How many of us are there? Owners of Dodge based RV's?

[whiteknight001]

I'm new here, and curious.

How many of us in Class C own Dodge B300 incomplete
cab/chassis based RV's? I know two others- Steve aka
Ripsaw, with a 1977 Brougham, and Leroy aka 1978_Dodge
_Delta who owns a 440V8 powered sharp looking 1978
Delta RV. I would like to ask, and offer, help, idea
swapping and comparing notes on our particular RV's
which are based on the Dodge B300 van chassis.

Yeah, I know. These are low tech, podgy old RV's that
would be considered "entry level" for folks like me,
but I have a deep and abiding respect for the quality
of these old "monsters of the open road". And anyone
wanting to pick brains, joke about, share notes or just
brag about our old A- Dodge-io's are certainly welcome
to PM or email me. Between all of us we can form a real
good support group, and help each other with problems
we know we'll encounter with an older vehicle.

Sure. I'd love a new RV. But I'd rather have an older
one already paid for, and a lotta great memories. Call
me frugal, an old hippie, or whatever you will. I'm proud
of my old land yacht.

Mopar Madness Manifest in the flesh,

Mark aka White Knight

P.S. Mine's a '72. Is there an older one out there someone's
motorvating in? Maybe even a Travco? W/K

[Griff_in_Fairba]

Assuming Jerry has solved the first part of his problem -- finding the little bugger (i.e., coolant temp sensor), let's try to solve the second part -- getting the temp gauge working.

Instead of just addressing his problem, I want to take a more general approach on the assumption other people will run into similar problems.

This will require several posts, as I take time to gather information and write the posts while taking breaks from other stuff. (Such as getting things ready for winter ... which will be here in a few weeks or a month.)

Most of our older motorhomes have four gauges: Fuel Level, Oil Pressure, (Engine) Coolant Temperature, and Electrical Ammeter. The first three operate in a similar fashion and the same basic problems and troubleshooting techniques apply to all three. The fourth (Ammeter) is an evolutionary holdover who's operation is an anomaly compared to the first three.

I will be focusing on the first three because of their similarities and ignoring the fourth because of it's significant difference. (Also, I consider ammeters to be functionally outdated, an opinion I will explain if anyone's interested.)

The following is oversimplified diagrams of basic gauge circuits. The top circuit demonstrates the basic wiring of gauges in older vehicles, such as most of our motorhomes. The bottom circuit reflects that found in newer computerized vehicles.



Note: Leeann may recognized this diagram. It's part of an article I started writing several years ago but haven't (yet) gotten around to finishing. (Back then, Leeann helped me with proofreading and editing what I've gotten done so far.) Also, this diagram is copyrighted by me and may not be used without my permission.

Missing from this diagram is a voltage regulator between the +12v and the gauge. Most gauges operate on nominal 5 volt current, which is an apparent technological holdover from the days of 6 volt automobile electrical systems.

In most older vehicles, a single voltage regulator (which is often referred to by other names) serves the fuel, oil, and temp gauges. This regulator is usually mounted on and wired into the instrument cluster.

Aftermarket gauges have a voltage reducer/regulator built into the gauge itself so it can be simply wired to +12VDC supply.

The gauges themselves are actually just voltmeters, displaying voltage levels ranging from zero to five volts.

The sensors, in turn, are variable resistors which vary the amount of current (voltage) in the circuit based on whatever they're monitoring.

When the fuel level/oil pressure/coolant temperature is low, the sensor increases resistance in the circuit. This causes the voltage to drop to near zero and the gauge needle to remain towards the left side. As these conditions rise, the sensor resistance drops, allowing more voltage into the circuit and causing the needle to move to the right.

At this point, you're probably thinking, "Jeez, this is simple." Well, you're right. It generally take me less than an hour to find and fix gauge problems and sometimes a little as five or ten minutes.

I have a good idea as what Jerry's problem is but I prefer the "teach a man to fish" approach.

BTW - there's been a revision to that saying ... "Give a man a fish and he'll eat for a day. Teach a man to fish and he'll sit in a boat all day drinking beer."

I'll stop here temporarily while I go do other things. When I take another break from those other things, I'll describe what can go wrong with gauge systems and how to find the problems.

(Yes, I will get back to starter vs deep cycle batteries eventually. However, Jerry's problem presented an opportunity to take a break from that and look at something that's simpler.)

[Griff_in_Fairba]

Wolf_n_Kat wrote:
Hey, I've changed out one of those!! Admittedly, it was a completely unrelated car and engine...

Jerry, those little suckers are 'maybe' about 3" OAL, and the hex head can be anywhere from 3/4" to 1". Like Griff said, they can be a wooly booger to find because it's kind of like trying to find a particular rivet on the Golden Gate Bridge - especially if the wire has come loose. (which is a pretty good analogy, considering most of that little basket-case is inside the engine block!)

I tried hunting it up, but the Haynes manual is relatively useless. Good luck!!

Oh hey, Griff... You mentioned getting 10 years out of the battery on your 1990 E-150? In 2009 the battery in my wife's 1992 Ford F-150 SWB 4X4 'gave up the ghost'. I went and picked up a new battery, and when I pulled the old one out I thought "You know, that battery tray looks awfully clean and shiny..." Looked at the old battery and turns out it was Motorcraft. 17 years on a factory original battery!

How often does something like THAT happen?!? 😄

Let me guess -- your wife's F-150 is a daily driver, primarily used for short trips around town and is rarely parked for more than a day or two between trips?

The kind of driving that's hard on fuel mileage and engine oil is actually very good for extending battery life.

Long battery life is more common than most people realize. Someone on the 'net said, "Most car batteries don't die -- they're murdered." With a little bit of care, a VRLA battery could easily outlast the vehicle it's in.

I know a semi-retired heavy equipment operator who's about 20 years older than me. He has a bulldozer left over from his working days, with a BCI group 4D battery that was 10 years old when he retired at age 65. (He showed me the receipt.) Nowadays, he mainly uses the bulldozer to plow his driveway in the winter.

When he's not using the bulldozer, he keeps a multi-stage charger/maintainer on the battery, with a timer that turns the charger on every three days. It's an open cell battery so he checks the electrolyte monthly. In the winter, he uses an engine hoist and cart to move the battery into his heated garage. (4D batteries are heavy and expensive, which is why he uses an engine hoist and performs regular maintenance.)

Extended idle periods (more than three days) are hard on battery life. Added to that is the fact the electronics in newer vehicles are a parasitic load that slowly drains the battery when the vehicle is not being used.

I like your "rivet" analogy when it comes to finding the coolant temp sensor. However, if I recall correctly, the sensor in older Mopar engines is only about one inch long and the stud has 8-32 threads. (If I get a chance, I'll try to find one of my spares to verify this.)

If I'm not in a hurry, I replace the OEM push-on connector with a ring terminal and lock it between two nuts on the stud. (The push-on connector has an annoying tendency to become loose and fall off.) I also use a Q-tip to apply a little dielectric grease to the stud, nuts, and ring terminal. (I also a little dielectric grease when I'm in a hurry and just push the OEM connector on the stud.)

As I've said before, be careful when applying the dielectric grease. The brass colored hex base is the ground part of the circuit and any dielectric grease that spans between the stud and hex base will create a short circuit that bypasses the sensor.

[Ballenxj]

Wolf_n_Kat wrote:


I tried hunting it up, but the Haynes manual is relatively useless. Good luck!!

I wouldn't give two dead flies for a Haynes manual. Never had any luck with them.
If I need to put out money for a manual, I will go out of my way to find one put out by Chilton's. 😉

[Wolf_n_Kat]

Hey, I've changed out one of those!! Admittedly, it was a completely unrelated car and engine...

Jerry, those little suckers are 'maybe' about 3" OAL, and the hex head can be anywhere from 3/4" to 1". Like Griff said, they can be a wooly booger to find because it's kind of like trying to find a particular rivet on the Golden Gate Bridge - especially if the wire has come loose. (which is a pretty good analogy, considering most of that little basket-case is inside the engine block!)

I tried hunting it up, but the Haynes manual is relatively useless. Good luck!!

Oh hey, Griff... You mentioned getting 10 years out of the battery on your 1990 E-150? In 2009 the battery in my wife's 1992 Ford F-150 SWB 4X4 'gave up the ghost'. I went and picked up a new battery, and when I pulled the old one out I thought "You know, that battery tray looks awfully clean and shiny..." Looked at the old battery and turns out it was Motorcraft. 17 years on a factory original battery!

How often does something like THAT happen?!? 😄

[Griff_in_Fairba]

Look here for help looking for the sensor.

The first picture shows why you're having trouble finding it. The alternator is on the left side of the picture, the upper radiator hose is on the right side, the heater hoes are on the top side, and the belts are on the bottom.

Farther down the page is a picture with an alternate location, next to the upper radiator hose housing.

In a motorhome, it's harder to find because the front of the engine is relatively hard to see.

[Griff_in_Fairba]

Okay, found an image ...



The part on the left side of the image is threaded into the water pump, intake manifold, or radiator hose housing ... the only part you'll see is the hex part, insulator, and small stud to the right of the larger threads.

[Griff_in_Fairba]

Jer&Ger wrote:
Hi everyone. It's been a while since I posted, but I need some help. I think the last time I posted I was talking about picking up another Dodge based RV & I was going to rebuild it. Well as life can happen sometimes, I'm still working on it. I could use some help on something that I have not been able solve on my own. My temp gauge is not working and I don't know where to start. I've checked online to try to find where the sending unit is located & not finding it. It's a '76 440. Any help would sure be appreciated. TIA, Jerry

It's not surprising you're having problems locating it ... I just did a quick google trying to find a good picture of the sensor ... most of the pictures that came up were of more modern sensors, with the more complex, multi-wire connectors required for use with engine management computers.

You're looking for something that looks like a small bolt head with a small diameter threaded stud sticking out the top. (Some have 1/4" blade connector instead of the threaded stud.) The fact that they're small makes them especially hard to find, as well as the fact they're often located behind hoses and other stuff.

Your sensor should have a single wire going to it, unless the wire has come off, which often happens.

Typical location is towards the front of the engine on the water pump, intake manifold, or radiator hose housing. (From what I can tell from a quick look-see, Mother Mopar put them in a variety of places on big block engines ... all located in the same general area near the distributor.)

Let's find it first and then I'll walk you through simple trouble shooting. (I know several possible causes, besides a loose sensor wire, that could cause the gauge to stop working ... all of which are simple to diagnose.)

[Jer_Ger]

Hi everyone. It's been a while since I posted, but I need some help. I think the last time I posted I was talking about picking up another Dodge based RV & I was going to rebuild it. Well as life can happen sometimes, I'm still working on it. I could use some help on something that I have not been able solve on my own. My temp gauge is not working and I don't know where to start. I've checked online to try to find where the sending unit is located & not finding it. It's a '76 440. Any help would sure be appreciated. TIA, Jerry

[Griff_in_Fairba]

Ballenxj wrote:

Griff in Fairbanks wrote:

After 5 o 6 unsuccessful attempts, hook up a battery charger and go get a cup of coffee because you've probably flooded the engine.

That's assuming it's a carbureted vehicle? Do fuel injected ones flood?

Yes, I was referring to carbureted vehicles. Unless I specifically mention newer technology, such as fuel injection, it's safe to assume I'm talking about older vehicles. (As a teenager, I started with a 1947 Willys Overland wagon and moved "up" to a 1949 International Metro van.)

I only know of one case of fuel injection flooding. An acquaintance tried to boost engine performance by drilling out his injectors. He didn't realize he would have needed to reprogram his computer to stand any chance of this working. The result was crappy performance when the engine actually managed to run and top end performance effectively disappeared.

Fuel injector system problems are typically the opposite of flooding. Instead, fuel starvation is the usual problem, due to gummed up injectors or malfunctioning high pressure fuel pump. (My 1990 Ford E-150 van has three fuel pumps ... one in each of the two fuel tanks and a third inline pump that boosts fuel pressure to the level needed by the injectors.)

It's also safe to assume I'm talking about cooler or colder temperatures. (Most of my vehicles experience difficulty when ambient temperatures rise above 80°F.)

LPG (i.e., propane) remains in a liquid state when temperatures fall below -30°F. Vaporization of gasoline is slower than propane, even at temperatures above zero. So, colder temperatures increase flooding problems.

Newer computerized vehicles arguably have an advantage over older vehicles. The multitude of sensors allows the computer to continuously adjust the engine to compensate for a wide range of conditions, such as ambient temperature, demand on the engine, etc.

There's a downside to the computer's ability to compensate for the ignition system being in less than ideal condition. This ability allows people to ignore routine maintenance until things are so far out of whack that the engine simply won't run.

A well-maintained computerized engine is slightly more efficient than an equally maintained non-computerized engine. However, the improvement in efficiency is not as great as most people believe. This slight efficiency advantage quickly disappears when people fail to properly maintain their engine.

A little more than 15 years ago, I proved a non-computerized, carbureted engine can be set up to be more efficient than a newer vehicle. After rebuilding the 351M engine in my 1980 Ford Bronco, I got access to an expensive diagnostic machine, which we used to "dial in" the engine specifically for my typical uses. After tweaking the ignition and carburetor, we put it on an emissions measurement machine and the results surprised the emissions technician. He discovered my engine was putting out less emissions than a new vehicle, even testing a car with less then 500 miles for comparison.

Before closing, I'd like to point out something in my previous post you may have overlooked. Assume a poorly maintained engine with thicker oil. Starting this engine in colder temperatures would require extended cranking, routinely drawing the battery down to the 30% discharge level. On a daily driver, assuming two starts per day, the battery would be tango-uniform in less than six months.

On the other hand, consider the OEM battery that came with my 1990 Ford E-150 van when I bought it, with less than 10 miles on the odometer. This van was my daily driver and the original battery lasted over ten years before I was finally forced to replace it.

[Ballenxj]

I think I may have murdered a battery or two when I was young and knew everything. :R

Griff in Fairbanks wrote:

After 5 o 6 unsuccessful attempts, hook up a battery charger and go get a cup of coffee because you've probably flooded the engine.

That's assuming it's a carbureted vehicle? Do fuel injected ones flood?

Griff in Fairbanks wrote:

It's 1:00am so I think I'll stop here and leave deep cycle battery differences for my next rambling.

This one should be interesting. :C

[Griff_in_Fairba]

Time to continue my ramblings with, as promised, starter versus deep-cycle batteries.

Note: "Starter" batteries are often called SLI (starting, lighting, ignition) batteries in an apparent effort to refocus the descriptive name applied to these batteries.

Starting an engine requires a very high rate of discharge spanning a brief period of time.

As we've seen, initial demand on the battery can be as high as 1500 amps for a period lasting up to two tenths of a second. Demand then tapers off to several hundred amps, for a total discharge period of 10-15 seconds. (10-15 seconds may not seem very long but imagine holding the ignition key in the start position for 15 seconds to get an idea how long it really is.)

The size of the engine and its compression ratio are the two primary factors determining the size and duration of discharge demanded by the starter. Other factors include type and condition of the fuel and ignition systems, ambient air temperature, and oil viscosity,

The size of the battery, the electrolyte formula, and the battery's internal design and construction determine how well the battery can meet the demand placed on it by the starter.

The initial surge of electricity comes from the electrochemical process that occurs where the lead and electrolyte molecules are in direct contact with each other. Manufacturers design their SLI batteries to have the largest possible lead surface area to increase the size of the lead/electrolyte boundary, resulting in the highest possible amount of amps during the initial surge.

Ideally, very thin lead plates, separated by thin layers of electrolyte, would allow more surface area in each cell. While this would create a very large initial surge, the battery's charge would be quickly depleted. Thin layers of lead and electrolyte also create issues in terms of battery durability.

As a result, manufacturers have to balance a battery's physical size, durability, and magnitude of the initial surge, along with the amount of time it takes to deplete the battery's charge.

As the available electrons in the lead/electrolyte boundary are depleted, the process spreads outward, drawing upon molecules located deeper in the lead and electrolyte. This secondary electrochemical process takes longer and produces less amps than the initial surge, effectively serving as the battery's reserve capacity.

It's worth noting that the curve on a graph of a SLI battery's output in terms of number of amps over time is very similar to the demand curve of a starter.

The design and construction trade-offs needed to produce a SLI battery results in limited reserve capacity. Therefore, SLI batteries are designed to produce intense burst of energy for a short period before being recharged. They are not designed for continuous draw over an extended period.

The typical starting cycle draws less than 3% of the battery's charge. Deeper discharges shortens a SLI battery's lifespan, with a 30% depth of discharge limiting the lifespan to 130-150 discharge/recharge cycles. 50% discharge reduces the lifespan to 100-120 cycles and 100% discharge shortens the lifespan to as little as 12-15 cycles, which is one-tenth the 30% discharge lifespan.

Whenever I hear somebody cranking their engine until all they hear is the relay clicking, I can't help thinking, "Another battery's just been murdered." Growing up in northern Minnesota and living in Alaska since 1980, I've seen quite a few batteries being murdered, as well as murdered a few myself. It didn't take me long to learn how to keep from murdering batteries in subzero temperatures, which are especially hard on batteries. (And, I'm grateful to the old-timers who helped me learn this.)

In subzero temperatures, you quickly run into the law of diminishing returns. Limit your cranking to 5 to 10 seconds. If the engine hasn't tried to start (i.e., fired at least one or twice), wait 3-5 minutes to allow the battery to build up its surface charge before trying again. After 5 o 6 unsuccessful attempts, hook up a battery charger and go get a cup of coffee because you've probably flooded the engine.

This assumes you've prepared your vehicle for cold weather with an ignition tune-up, winter weight oil, and fuel system and choke adjustments if necessary. In high school, my buddies and I made hundreds of dollars jump-starting college student vehicles, which were probably fine in Minneapolis but not tuned-up well enough for the -20°F and below temperatures common in Bemidji.

It's 1:00am so I think I'll stop here and leave deep cycle battery differences for my next rambling.

This is necessarily a significant generalization. Many (most?) professional electrochemical scientists and engineers don't fully understand what goes on in lead/acid batteries. As a result, these batteries tend to be magical mystery to the average person, which leaves the door open to a flood of misinformation and questionable gimmicks. One place that seems to have reliable information is the Battery University website.

[Ballenxj]

Griff in Fairbanks wrote:

Ballenxj wrote:
You have been a wealth of information here.
Just sayin, in case there were any doubts.

Is this a nice way of saying I'm a know-it-all? :B

Well, my Mama always said to mind my manners. 😉

[Griff_in_Fairba]

regis101 wrote:
OK. I'm calling it. Party at Griff's place. Who's in??

Yah, sure ... like any of you will make the trip just for that. One of the advantage in living in Alaska is it's much more unlikely for the in-laws and out-laws to just drop in. (According to my dad, if your spouse's relatives are in-laws then your relatives must be out-laws.)

Besides, I recommend going to the Kenai Peninsula instead of coming to Fairbanks ... lots more interesting scenery and things to do. (I could easily spend a month or more just wandering around the Kenai.) If anyone does plan to come up here, I'll map out a fun-filled, interesting trip, including things average tourists don't get to see or do. Regardless, I wouldn't recommend coming up before May 1st or after September 30th. (Even then, you'll probably run into at least one snow storm.)

Leeann wrote:
How far along on the house are you?

Main floor diaphragm (joists & subfloor) is done, caulked, and sealed with deck paint. Been working on basement floor. Raised wooden basement floor instead of slab, with subfloor/joists resting on box beams on sill plates on foundation footings.

Ballenxj wrote:
You have been a wealth of information here.
Just sayin, in case there were any doubts.

Is this a nice way of saying I'm a know-it-all? :B

[Ballenxj]

Griff in Fairbanks wrote:

BTW - turned 60 years old on the 17th of this month.

Well then, HAPPY BIRTHDAY belated. 😄
You have been a wealth of information here.
Just sayin, in case there were any doubts.

[Leeann]

Happy Birthday!

How far along on the house are you?