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Starts, shuts down after a second, and wipers start going...

Rodzlla

Well-Known Member
Messages
85
Location
Northern Virginia
I apologize in advance for the book this will likely turn into.


A couple months ago, I took the battery, fuse block, and alternator out of the engine bay to prepare for the replacement of the intake manifold gasket and the camshaft cover gasket. After the gaskets were replaced, the alternator, fuse block, and battery were put back in. I was stoked to get the truck back on the road. Nope.


When I started the truck, it started, ran for a second or two, shut down, and the wipers started moving on their own. The truck would not restart. The wipers continue to wipe the windshield for a little while and then stop.


As I started reviewing connections and trying to troubleshoot this odd situation, I found the megafuse was blown. I went and bought a new megafuse. I replaced the megafuse and tried the ignition again. This did not change the no run condition. I started pulling stuff out again making sure things went back together correctly. When the fuse block was being put in again, I think I heard an extra click. I could be wrong, but the truck started up and stayed running after it was back in.


The truck ran fine for probably 45 days (allowing me to get it through safety inspection and emissions - thanks Virginia for another set of headaches). A couple weeks ago, the truck would not start again. Same thing... start, shut down after a second or two, and wipers turn on by themselves. Tow bill of $100 to go 2 miles back to my driveway.


So frustrated. I have a ton of work to do/finish around the house. Gotta keep my family happy and get ready to host out of town guests soon. I have not turned any wrenches on it since it was delivered to the driveway.
I did squeeze a few minutes out of an afternoon to fiddle around recently. I tried to start it up. Same result. No change. However, if I turned the auto headlight switch to the off position, the truck started. It stayed running until I turned the headlight switch back to auto. It then shuts down again.


I am fed up and unwilling to spend my evenings and weekends in the driveway under the hood. I am entertaining to option of taking it (via tow truck) down to the dealership and paying at least for the diagnostics charges. I really hate the idea of paying for the dealers time. Please help me avoid that.


I know there are some very knowledgeable Hummer minds here. Have you had this happen to you? Any ideas even if you have not had it happen before?

Thanks in advance.
 
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adventuredad

Well-Known Member
Messages
86
Location
Southwest WA
Definitely check the pins under the fuse box. When I got my truck, the cruise didn’t work and the temp display didn’t either. After reading through posts I found that mentioned and decided to tackle it one day. When I removed the fuse panel, the plugs under had been removed previously and were all jacked up. Finally found the pin that powers those things had been bent over, a little straightening with needle nose pliers and I was back in business.

Apparently those plugs can be challenging and are notorious for bending pins. I could totally see bent pins causing strange connections and blown fuses. This could easily cause a lot of strange behavior. That’s where I would start since you’ve already had it removed once.


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Jeepwalker

Well-Known Member
Messages
857
Location
WI
This is probably too simple, but quadruple-check your battery connections (and maybe grounds and engine/body ground). What makes me say that is when you engaged your headlights, perhaps the large amp-draw caused a 'spark' across perhaps a lousy + or - connection ....and the spark 'made' the connection good enough to start. Just a theory. Easy to check. These things are finicky on connections.

Also, do you think your starter solenoid could be failing? (or loose connection down there)
 

Rodzlla

Well-Known Member
Messages
85
Location
Northern Virginia
Adventuredad, I will pull the fuse block out one more time. Maybe there is a bent pin. I suppose that is a real possibility. I will try to check into this later this week.
 

Rodzlla

Well-Known Member
Messages
85
Location
Northern Virginia
Jeepwalker, I will take a look at connections again while I am looking at the fuse block plug pins.

As for the starter solenoid, I doubt this is the problem. But I will check those connections too.

Thank you.
 

Rodzlla

Well-Known Member
Messages
85
Location
Northern Virginia
All the more puzzling is the 45 days or so that it ran fine. I worry that something more complicated is at work here. Like the BCM is screwed up (since I assume the wipers are linked into it) and it somehow resets and 45 days from now, I will have all this happen again.
 

Traxx

Well-Known Member
Messages
682
Location
PNW
Most likely bent a pin reinstalling the fuse box, it is very easy to do. They can get folded back on themselves, I've done it once and it took me a fair while to find what pin it was.
 

Jeepwalker

Well-Known Member
Messages
857
Location
WI
When power and grounds get goofed up on modern vehicles (and electronics in general), odd things happen. In part it's b/c chips and latching relays are looking for a certain minimum quality of power. When they don't get it, their logic (in the case of microprocessors) get screwed up. It may 'kinda' work ..but not quiiiite right. It happens in electronics all the time which I play with on the side. Kind of like a VCR or CD player that would suddenly do 'odd' things like it had a mind of its own ...are almost always due to a power supply issue (failing capacitors) or poor switch or connector. I get (and repair) free electronics all the time. Very rarely is it something complex.

I've had similar issues with other vehicles and I understand how frustrating it is. After checking the pins, really go back and tripple-check the connectors you unplugged, and ALL the grounds and power connectors you can find. Some vehicles have a main ground connector too. And other fuses and below the fuse panel (not uncommon on outdoor fuse panels for corrosion on the underside.). I wish GM would have forgotten about highly integrated electronics. Sometimes I question what 'true' benefit it yielded ...but anyway we have to deal with how the world is as it is, right?

Good luck
 
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High Five H2

Well-Known Member
Messages
1,627
Location
West Texas
I had issues in my H3 with the wind shield wipers being on all the time. There was some corrosion at the bottom of my fuse box and the wiring harness to the ECU had been damaged when I sent the ECU in to get it programmed. The shop replaced the fuse box and repaired the harness and it fixed the problem... mostly...
 

Jeepwalker

Well-Known Member
Messages
857
Location
WI
Unfortunately it's becoming more common on a broad spectrum of vehicles where the ECM and fusebox become integrated and are exposed more to the elements than in prior years. I'm on a few other forums (different vehicles), and owners have noticed similar corrosion problems. Not just a GM thing.

Off-roading can accelerate issues.
 

JPaul

Well-Known Member
Messages
2,400
Location
Way up north, UT
All the more puzzling is the 45 days or so that it ran fine. I worry that something more complicated is at work here. Like the BCM is screwed up (since I assume the wipers are linked into it) and it somehow resets and 45 days from now, I will have all this happen again.
When I had the issue of the connector not being pushed in all the way, it took a while before it started showing symptoms. It might have been in enough before to have contact but then jostled loose over time. Still worthwhile to check the connections.

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4speedfunk

Well-Known Member
Messages
4,212
Location
Tardville
Use mechanical logic:

Problem started after you did some work under the hood. Most likely it is something you disturbed when doing the motor work. So go back and triple check everything you touched. The fuse box design on the H3 is horrible and the harness connectors are very difficult to work with. As many others have mentioned...it’s probably a bent micro-pin inside one of the connectors, or the connector is not fully seated.
 

Rodzlla

Well-Known Member
Messages
85
Location
Northern Virginia
I just got back inside from an hour or so spent looking at the things mentioned above. I reviewed the grounds, wiring from the battery to the alternator, the wiring to the fuse block, etc. I took the battery connections off, pulled out the fuse block, and checked for bent pins. None found. No corrosion on the pins or the plugs/connectors. I reassembled everything being sure the fuse block dropped in the base and connectors properly. I reattached the battery connections. Tried to start the truck... Now it will not crank/start at all (not even for a second). I shut the hood and walked back into the house just as frustrated as before.
 

4speedfunk

Well-Known Member
Messages
4,212
Location
Tardville
Wait a half hour...then try again.

When you disconnect the battery on an H3, the passlock system will sometimes block the truck from starting. It will also grab the key and lock it to the tumbler on the column. This will normally reset within a half hour.

If your battery is drained...it will need to be fully charged to clear the passlock system and release the key.

And yes...this is the dumbest feature in automotive history. Welcome to the wonderful world of GM.
 

Jeepwalker

Well-Known Member
Messages
857
Location
WI
I feel your frustration. Sucks. Been there. Try your best to keep a calm approach and keep posting the progress good and bad. Hopefully we can help you get to a point where operation is restored and it's a blast to drive again.
 

Rodzlla

Well-Known Member
Messages
85
Location
Northern Virginia
Do the other electrical features on the truck work, i.e. lights, key fob, locks, etc?

It seems that the other electrical stuff is working fine. Interior lights work fine. Turn signals. HVAC blower. Radio. All fine.

Just the wipers, headlight switch, and the ignition/starting are really affected.
 

Rodzlla

Well-Known Member
Messages
85
Location
Northern Virginia
Wait a half hour...then try again.

When you disconnect the battery on an H3, the passlock system will sometimes block the truck from starting. It will also grab the key and lock it to the tumbler on the column. This will normally reset within a half hour.

If your battery is drained...it will need to be fully charged to clear the passlock system and release the key.

And yes...this is the dumbest feature in automotive history. Welcome to the wonderful world of GM.

Went back out there today and tried it. No start. Wipers acting crazy again. Tested the battery and it is at 12.25 volts.
 

Alpha X

Well-Known Member
Messages
409
Location
The Motor City
Went back out there today and tried it. No start. Wipers acting crazy again. Tested the battery and it is at 12.25 volts.

I believe a battery charge of 12.25 volts is low, about 50%. You may want to fully charge that thing so it reads 12.6 volts. Perhaps a parasitic drain test will help point you in the direction of what's happening and where something may be going wrong. With a multimeter, you may learn some valuable info. I've seen some nice examples of how to do this on youtube because I need to do one as well. The more elaborate parasitic drain test requires you to look up the amperage of each fuse, to compare what it's supposed to draw, versus what it actually is drawing. See youtube links below.



https://www.youtube.com/watch?v=lRcj1fQcWwU

https://youtu.be/n5FJDgcdii8
 

Jeepwalker

Well-Known Member
Messages
857
Location
WI
Does it make any sound at all when you engage the key?
I'd go out and give the starter (and solenoid) a few good raps with the wood handle of a big hammer or something similar (don't beat the crap out of it, but firm whacks). Sometimes the solenoid or bendix sticks. After I re-did the exhaust/intake on my Jeep last fall, it wouldn't start. After looking at "Everything" ...turned out the starter was stuck. It may have been the solenoid, I never de-bugged it once it began to work again.

Inside the back end of the solenoid (the black plastic cap), there are heavy-duty copper contacts that carry full battery power to crank the engine. Each time you go to start it, a plunger comes back and the contacts on the plunger make contact with the solenoid contacts ....which happen to be the back of the bolts where the cable connects to. In the micro-second before the contact is made, sparks occur. Over time it 'eats' away at the copper and it becomes heavily erroded. Eventually, when it gets worn enough the contact may or may not fully 'make' causing a no-start situation. Ok, you may know all that, and this may not be your issues, but it's a good idea to double-check the basics while you're going down the tree of probable problems.

Again, this may not be your issue, probably not. But I would at the very least, whack it, and hook jumper cables or a remote starter to it to ensure it's operation, just so you don't mistakenly overlook a bad starter/solenoid or wiring down there. I'm on the Jeep forums a lot. 95% of the no--start or poor operation posters come out of the chute blaming the computer. Often the posters will have replaced 1/2 of the sensors and spent days or weeks thinking it was a very technical problem. And 94.5% of the time the problem ends up being associated with wiring, connectors, bad grounds, fuses, sensors, battery, vacuum, fuel pressures, etc.

6782N_2.jpg
 
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Traxx

Well-Known Member
Messages
682
Location
PNW
If the battery is good, cable ends have been replaced, then oddball electrical problems in these rigs generally start with the bcm.
 

4speedfunk

Well-Known Member
Messages
4,212
Location
Tardville
I agree...BCM would be next on my list. Clogged sunroof drains can funnel rainwater right into it. Again.... corrosion should be obvious. Remove the plastic cover in the passenger side footwell...the BCM is behind it.
 

Jeepwalker

Well-Known Member
Messages
857
Location
WI
I agree...BCM would be next on my list.

It's worth a shot. The only thing making me question it are two critical factors:

1) The problems began after you did your repair work (that's how I understood your post). Pointing towards some undiscovered issue that occured during your work. Which, if true, won't change after installing the new BCM. It's possible the BCM may work initially but after going through a 'learning process' may go into the same issue (not likely, but possible).

2) According to GM's own comprehensive study, the vast majority of computer modules returned as 'bad', were not faulty when tested. In cases when the problems did go away after replacing a computer module, the mechanic may have found the real problem (and never reported to the customer) ..or it was a case of bad connectivity or grounds which were resolved in the process of the swap-over. Now granted, the study I read was done some years ago, but EVERY frickin' car owner seems to quickly blame the computer when in fact they've shown themselves to be quite robust. I do believe you can send it in to be tested, which may be an option.

3) Knowing all this is why the FIRST items on the troubleshooting pages of service manuals is to thoroughly inspect a battery of items, wiring etc. to eliminate the 90% of most likely problems. FCA, Ford, GM ..they all indicate the same process in service manuals.

But having said that I know how frustrating it can be (I've been there banging my head on the wall), and the chance it may resolve your problem is worth a shot. I get that too.
 
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SoCalH3

Well-Known Member
Messages
106
Location
Beaumont
I had the exact same problem including the wipers going when I first bought my H3 Alpha, extremely frustrating! I even have those same notes on the invoice from the dealer. Happened about 1 in 20 starts. If I moved wires around under the hood, it would eventually restart. The first time the dealer couldn't replicate. The second time they figured out that it was a bad BCM part # 25816709 and replaced the Fuse and Relay Block part # 25908816. I was fortunate enough to get GM to agree to cover the labor and I covered the parts. I paid $828 out of $1463. Some how they ended up messing up the instrument cluster and replaced that on their dime of course. That was all in 2014.

After reading Jeepwalker's comments above, I'm wondering if either the instrument cluster was the original culprit.. Or possibly a problem in the cluster killed the BCM? It seems like they had to re-order the BCM after installing it.
 
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Jeepwalker

Well-Known Member
Messages
857
Location
WI
The second time they figured out that it was a bad BCM part # 25816709 and replaced the Fuse and Relay Block part # 25908816.

I say you replace the BCM ...and ONLY the BCM (not touching any fuseblock or any other wires or connectors) and see if that resolves the problem. Most times multiple things get replaced and there's no way with any degree of certainty to say it was the BCM. The 'black box' always makes a convenient target, even for GM.
 
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