Weird Electrical Issue/ Need experience of RV.net

[Shacklaw]

If you recall the scene from Indiana Jones where he looks into the pit and says "SNAKES, it had to be snakes"...that's me right now.

I'll try to condense-I've had this poor ol' coach for years. Last time I actually used it as a coach, I was having an issue of draining batteries and a small "shock" from the frame if you were sweaty and touched it, but it was manageable. It thereafter became the building office for our house, was taken to the lake to be the building office for the lakehouse, was brought back home and allowed to sit for a couple of years. About 5 years total. I have now decided to restore it.

I attempted to start it. No go. Fresh battery, jump box, nothing.
Changed starter. Rolled over several times, spuddered. Nada.
Check the battery drain with multimeter on amps on negative post,
23.4 amp draw with everything off. It would go to 34, then down to 10.5, then 0, then back up. Never stayed constant.

I isolated the chassis side from the coach side (as far as I can tell) Coach Batteries out, bird disconnected, etc.

All that is left is: Power cable from chassis battery to on/off solenoid, (power equal on both sides), cable to bird, bird to starter. If you don't connect the 2 cables at the bird (battery and starter) no power loss. As soon as you hook the 2 cables together (that's their normal config.) you get a 23.4 amp draw. Alternator completely disconnected. Seems to be from the cable to starter.

New Starter (same results with old, so it was good) a main cable to the solenoid, a small wire to the start pole, and a light purple heavy wire from the main cable lug up into the loom towards the dash. Best I can tell that's ALL that's hooked to the battery.

I'm stumped!!!! The light purple wire goes somewhere. I see it go into the loom, but I have yet to find it on the other side. Does it go to the ignition switch? Fuse panel? Where?

This is a lot of draw for NO FUSES being blown. I've check all fuses under the hood, nada. Out of ideas on where to look. Ignition switch? Fuel pump? What could draw that much amperage and not be easy to find? IDEAS?

[BobcatDriver]

A reasonably priced clip-on AC and DC digital current meter plus volts; MASTECH MS2108 at about $60 on the internet. Two current ranges, 40 and 400 amps plus regular DVOM settings.

[Shacklaw]

Not yet! I was so happy it ran I forgot! Can't get back to it for a few days, but I will check that out! Thanks

[enblethen]

At least you are moving forward!
Did you check the wiring output from the oil pressure sensor to the fuel pump?

[Harvey51]

Great news!

[Shacklaw]

Ok!!! I just wanted to update. I went and ground paint and rust off of the chassis and replaced and improved the old grounding system.(Chassis/motor side only so far) Success!!! After chasing gremlins and think, rethinking and overthinking, it was in fact a ground issue. Amp draw at present, ZERO. MAmp draw is about 148Ma. I was told it should only be about 50ma, but I'm happy!

Fresh new battery, hooked a Holley inline low pressure pump I had in the shop, and BANG, she started first hit! Let her run for 45 minutes or so, no issues other than a service light (knock sensor-likely poor gas) and it's exhaust smells bad! Ugly gas!

Anyway, wanted to update and say thanks to all! It was a big help as always. I'll be back I'm sure when I move to the Coach side! haha!

[enblethen]

It could be a ground issue. I replaced the battery to engine cable a while back. It was pretty burnt where it attaches to a bolt on the intake manifold near the AC compressor.

[Shacklaw]

Thanks, will track power to pump tonight. Idiot lights come on. I've been poking around at this thing by myself, likely get my wife involved. LOL! Long way back to the tank to hear the pump.

Decided maybe I've been looking at it the wrong way. Called a hotrod buddy of mine, and first thing out of his mouth was "bad ground". "Too simple" I said, and immediately did some "grounding" improvement work.(He's rarely wrong) We'll see if that helps in tonight's session.

[enblethen]

Does your dash idiot lights come on in the on position?
If the voltage is low or not getting good voltage the engine will be difficult to start as the ECM voltages may not be high enough for sensors.
After the fuel pump runs for the few seconds, the power to the pump comes through the oil pressure sending unit. Verify that the connector is tight on sending unit. It should have voltage on the orange wire. this is the same orange wire coming from the fuel pump relay. It then sends power to the pump on either a tan/white or grey wire.
Do you here the fuel pump run. Have helper turn on ignition switch while you listen close near the tank.
Hows you fuel filter? On frmae rail passenger side near rear axle.

[Shacklaw]

Thanks guys! If the internal fuse is blown, will it read at all? Still getting amp readings. I was surprised, thought 10a and boom!
Pump relay was right where you said it was, thanks enblethen. I pulled it this morning before work, plan on doing amp readings this evening with it out.

Engine is not seized, actually had it spudder on starting fluid and build oil pressure, so that was a relief. (Did make me pucker a little until it rolled over). My background is high performance/offshore race boats, so when they sit for awhile, we just pull everything and go through it. I built this motor and redesigned the injection system, but it's still just a motor that's been sitting for awhile! haha! Kind of my first attempt at starting something "as is-where is" and I must say, it's been kind of different.

I used some stuff called Pri-G in the fuel, then added 5 gallons of premium. I use it to winterize boats and atvs, etc. Snake oil guys on Youtube claim it will at least make old gas burnable, others say it will return it to factory fresh (hmm), but we'll see if it works at all in this application.

I have changed all the ground wires to the battery bank (6v are out right now) and made sure I had good ground to all components and drivetrain. Didn't get an opportunity to test anything, as by the time I spent messing with it yesterday, it got late and my older battery wasn't charged enough to be accurate I didn't think, so I just packed it in for the night.

Hope to be able to get onto it tonight. Still not getting fuel to the TBI either, so seeing if that is a symptom or separate issue.

Thanks again for all the help! Good ideas all! I'll keep you posted.

[Harvey51]

I doubt if there is a significant current drain with everything turned off. So sorry you blew your Fluke's 10 amp range; easy to do. The thing is, to measure current it must flow through the meter so you must open the circuit (unhook a wire) and insert the meter in the circuit.

As a rough check for lost current, charge the battery well, wait overnight and see what voltage it has. 12.6 is fully charged, 12.0 is half charged. If it's only down a tenth or two don't worry about it now.

The jumper cables from battery to starter suggestion is really good; there undoubtedly is corrosion in the cable end connections. I bet you end up buying new cables.

Can you figure out if the engine is seized? Like pushing or pulling it in gear? My dads old tractor wouldn't start after sitting for several years, was seized. I put a quarter cup of light oil in each cylinder through the spark plug holes, left it for two weeks and it turned over. Unfortunately I tried too long and burned out the starting motor. (My dad was over 90 and could no longer crank it. When I was 18 I could turn that crank a quarter turn while he could do half a dozen. Old age can feel like hell.)

Consider the condition of the old fuel. Best to get as much as you can out of the lines and tank before attempting to start. I have no idea how to dispose of it - ask at your recycle center. I hope it is old enough to allow a siphon hose into the tank and has the fuel pump outside the tank. Carburator? Injectors? Fuel pump? Filter? Worth getting professional advice or help before attempting to start it again!

[westend]

Your Fluke has already blown it's amperage fuses when you directly connected to a draw greater than 10.5 amps. No idea about the measurement you have.

Here's what I'd suggest first: Make sure your solid state BIRD is functional. One way to test this is to measure voltage at the starting battery and then measure voltage at the coach batteries. Push the "aux" jumper button that connects them and see if the voltage rises in the lesser battery.

Next, I'd completely disconnect that BIRD and try to start the vehicle with just the starting battery. Measure it to make sure it has a good charge before start initiation. If it's low (likely), put a charger on it.

You have a couple of problems---a battery interference because of a drain, a vehicle that hasn't seen constant use and may suffer from all the ills that entails (fuel system clogging, bad gas, ignition components not serviced, etc).

I'm kind of amazed that you seem frustrated about starting this vehicle. You may not have any experience with vehicles that are stored for a stretch but, for me, it is always a drama of covering many steps to get them functional again.

[enblethen]

Did you disconnect the alternator main cable?
What happens when you use the "aux" start?

[Shacklaw]

I forgot to mention that. Had meter on outside, went through EVERY fuse in the "Control Center" under the hood, then set up some jumpers and moved the meter inside, went through all the fuses under the dash. Nothing!

I do believe when I go to the Start position, whatever it is is sucking SO MUCH amperage in the start position the starter won't hardly turn the thing over. I got it to fire and spudder on starting fluid for a few seconds, but it zapped all the battery life.

That's what kind of started the whole thing. I would leave it at the lake, plugged into shore power. All seemed fine, come back next weekend and all the batteries are dead as a doornail! Seemed Amps draw exceeded the converters ability to charge.

[joshuajim]

You could start pulling fuses one at a time until the amps drops.