Suburban dilemma

[Fryer5]

Last year I bought an 08 suburban 2500 with 51,000 miles. Body in excellent condition. I planned on using this to tow my trailer and be an everyday driver for my wife for many years to come. It ran and drove with no noticeable problems at all. I changed all the fluids, difs, transmission flush, transfer case. Gm dealer didn’t recommend a radiator flush at that time.
Now onto the problems
1. The stupid thing has ghost in it. An electrical problem that randomly completely resets the computer. The clock will be reset. No error lights on the dash. Sometimes when this happens it will not start. Turn key, NOTHING, no click, no dim lights. NOTHJNG. wait 1!hour, starts right up. It has done this to me twice while driving, leaving me and my family stranded on the side of the interstate. Once while pulling the camper.
2. The rear end is making a horrid noise, probably the pinion bearing. This truck has the 3/4 Ton 8 luv axle, it has been properly serviced by the dealer, and yet has spun a pinnipn bearing? Very frustrating.

So, I guess the advise I am looking for is should I fix it and keep it? (No one has been able to find the “ghost” electrical problem despite several thousands of dollars in repairs)
Or do i send it on down the road and start looking for it’s replacement.
To be honest, I am really not in a good place to be looking for new suburbans financially.


To add to this, my wife of course is saying never again to this truck, and after this expierence I am not wanting to buy another used suburban.

All input appreciated

Fryer 5

Ps. I have always been a GM fan, and still am. My other two chevys serve my family great

[BurbMan]

BenK wrote:
The fusible link is just that, a fuse via a length of special wire. Once it is over loaded, it is gone and there is no reset like a circuit breaker. Unless things have changed on newer vehicles.

I think the newer vehicles use an auto-reset circuit breaker in place of the old fashioned fusbile link.

[Groover]

A totally different idea is to inspect the wiring for rodent damage. I had a car acting really weird and thought that the transmission was out. The shop started taking the transmission out but found where some rodents had gnawed on the wires. He patched the wires and solved all of my problems.

[BenK]

Thanks for posting an update

The ignition key should not be the cause, as it is only in the game when you want it to run and the OP says it resets over nite when the key isn't in the game... Just think of what it would take to reset the computer/clock/etc over night when it is just sitting there 'off'...

The fusible link is just that, a fuse via a length of special wire. Once it is over loaded, it is gone and there is no reset like a circuit breaker. Unless things have changed on newer vehicles

A remote possibility if it is within the fusible link...an intermittent and is akin to load dumping the system

Good to hear that the battery is replaced, but the alternator and other chips that saw load dumping are still a potential problem that might create another load dump situation. Mainly the alternator diodes and might take down the new battery in short order

As Burbman stated, the high voltage spikes from constant load dumping will create shorts inside the battery to manifest itself in a flaky battery...that then contributes to more load dumping of the whole electrical system (voltage spikes)

Think of taking a 110 line and touching the electrical system on a regular cycle and only just a moment. That is what load dumping is...spikes of that kind of voltage or even higher. That will punch holes in the silicone chip...that will either open and/or short

Good luck

[punomatic]

newman fulltimer wrote:
those were known for the ignitions going bad. As far as the rearend take a look at 5he pinion yoke nut probably alittle loose

This was my first thought. I had a Chevy Cavalier that had a ghost like yours. After I spent hundreds on a new fuel pump and other electrical components at Chevy dealerships, a local mechanic found the ignition switch was bad. Problem solved.

[BurbMan]

It's entirely possible that the battery was causing the problems. It may have been shorting internally and causing the main circuit breaker (previously known as the fusible link) to trip. That would kill power to the whole vehicle and after it auto-reset all would be fine again.

That intermittent short finally got bad enough where it wouldn't hold a charge and the battery died.

[Fryer5]

Yes well, update. After having it back for more than a week, driving it everyday, I have had no problems with miscellaneous electrical problems. The clock/computer has not reset since I put the battery in. We are currently about 200 miles from Home, north (no camper or trailer). It gave me trouble on the trip up. I am still concerned about the secondary fuel pump, might just replace to be cautious. I haven’t let it get below 1/4 a tank since I got it back on the road.
I really wish there was a definite answer as to what solved the electrical issue, I might not ever know. (And I might not ever trust it).

[BenK]

Ah...more info and indicative of "load dumping" circular cycle...never ending until both the battery and alternator (or more components, as they take out lots and lots of components in that food chain) are replaced with new or 'good' rebuilt

Know folks don't know...nor believe of 'load dumping'...so do a search for believable info

Here are a few found in seconds



Wikipedia...classic definition, mainly automotive


Just a basic info site on how an alternator works
Note that semiconductors do NOT like, nor survive for long seeing voltage spikes (load dumps). Typically filtered with R/C circuits, but some employ MOV's (and they are painted cherry bomb red for a reason)


Info on what "load dumping" is


One automotive "load dumping" circuit


But...the best solution is to have your electronics savvy mechanic do the diagnosis and work. Bottom line is that, IMHO, the battery, alternator and regulator are toast and needs replacement "at the same time"...

Your on-board computers 'should' have protection built into their power circuits to avoid the voltage spikes load dumping generates...but only up to a point before they are compromised. One condition that will compromise them is too many voltage spikes along with too high a voltage attained

Good luck

[Fryer5]

Before I took it to the mechanic, the battery was dead. I jumped it and it started and indicated it was charging. Next day, dead battery. I replaced it at that point as I had left the truck running the day before when I jumped it for an hour (trying to get it to die again which of course it didn’t) and the battery had charged and it would restart no problem. When I removed the battery, it wasn’t holding a charge, dropping one volt in an hour, which is why i replaced it. Previously, it had never killed the battery.
I am really at my wits end with this one.

[BenK]

Fryer5 wrote:
snip...

1. The stupid thing has ghost in it. An electrical problem that randomly completely resets the computer. The clock will be reset. No error lights on the dash. Sometimes when this happens it will not start. Turn key, NOTHING, no click, no dim lights. NOTHJNG. wait 1!hour, starts right up. It has done this to me twice while driving, leaving me and my family stranded on the side of the interstate. Once while pulling the camper.

Key to me...the only way to 'completely reset the computer' is to remove power to the computer...and the computer power circuit most likely has a large capacitor to both smooth (filter voltage spikes, transients, etc) and hold power for a few seconds or more...so that means power gone not just a second or so, but longer

That is where the problem is and where my suggestions started...with the power source...the battery

Has the battery itself been load tested ?

If it is bad...it could have also load dumped the alternator making it kill subsequent 'new' batteries

Or the circuit between the battery and the computer has an intermittent connection(s)

Since bought used...check if the fuse-able link has been replaced...or somehow compromised...or maybe previous owner(s) installed a battery disconnect system...stuff like that is my now best guess is the culprit

[Fryer5]

Update:
The mechanics say that the rear end is shot, $1685 for the rebuild
They have no idea on the electrical problems. None. It has given them zero problems in the 100+ miles they have driven it.
But they found a bad wheel bearing in the front.

[mkirsch]

Friend of mine's wife's mid-2000's Malibu had a gremlin where it wouldn't start, but if you left it sit for an hour it would make a liar out of you in front of the tow truck driver. Turned out to be a faulty ignition switch in the column, as I recall. Was a well-known problem.

[Fryer5]

I do like that idea, but definitely not in the budget

[Kenz71]

Half joking, convert it to a diesel which would mean new engine, trans & axles. All the problem parts replaced.

[Fryer5]

@burbMan. I am going to check into the duel fuel pump issue with the mechanic. That could explain it shutting down while driving, then cranking and not firing, and after an hour it would restart. The truck is currently just sitting, as I am driving my pickup until I get it fixed, and with it being Christmas shopping season I don’t have the money to get it fixed without incurring debt, so it will wait.

@BenK. Thanks for that info on n the negative battery cable. I did replace both battery cables with new AC Delco cables. I also added an extra ground from the body to the engine. I have read the TSB’s but I am not a mechanic. It is frustrating