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Discussion Starter #1
Today, while driving on the interstate, out of the blue the car died. And when I say died, I mean 100% dead. Not only did the engine quit but there was absolutely no electrical power - no lights, instrument panel lighting, turn signals, radio, nothing. It was as if someone disconnected the battery. I coasted to the shoulder, tried the key a few times (nothing at all - stone dead) and popped the hood to see what I could see, which was nothing. I wiggled a few connections (battery cables, ground connections, alternator plug, whatever random connectors I could reach) but nothing seemed loose or out of place. After a few minutes, whatever was wrong magically fixed itself. The lights came back on, dash lit up and I was able to restart the car. This happened twice more on the ride home. It's like that scene in Airplane where the runway lights go out and the guy says, "Oops. Just kidding." So there's obviously a loose connection or intermittent short of some kind. What should I be looking at? Where could I have a bad connection that would kill the electrical for the entire car?

Three things that may be relevant: First, a few weeks ago, I noticed that the large ground cable from the battery is chafed (I have Gary's battery cables installed). It's not chafed all the way through, plus I wrapped it in electrical tape and put a section of wring loom over it. I don't think it could be that but maybe? Second, and I think not coincidentally, over the last week my ABS light has illuminated for a minute or two several times while I was driving, and there were maybe three or four times when all of the dash lights (ABS, high temp, oil pressure, etc.) lit up at once, also while driving. The car didn't die, though. It didn't even seem to stumble. Third, a few times over the last week or so, including today, I have noticed that the dash lights seem to get dimmer and brighter as the RPM vary (brighter at higher RPM).

So, any suggestions as to where to look? Thanks.
 

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First off, it would not be a short, or you would blow fuses, or there would be sparks. So, it is an open, or a bad ground. It is something that is going to require troubleshooting with a meter. You will only be able to troubleshoot the problem when it is happening, so the timing of the occurrence will be critical to your solving it. Intermittent issues are the toughest to fix.


The assistance I can give is to hook up your meter, and start shaking wires and wiggling ground connections. The one clue is that it seems to be global in nature. I would start with the cleaning battery ground, and hot lead. Then check the cables for corrosion at the connectors.
 

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That, and strong indication it's associated with coming up to temperature. Something opening up as under hood gets hot.
That main post in the fuse panel?
I'm with the wiggling every wire, and hitting on everything that looks electrical, - when hot.
And I thought there's an issue with "instant dead" from a faulty ECT sensor and/or bad wiring to it. Yes-no?
Google symptoms of a failing ICM and coil.
Google things that fail an OPTI when hot.
Do our cars have a main breaker (not fusible link) that may be weak and resetting itself?
All dumb questions I know.

And yes, major cable corrosion fail can be hiding under normal looking jacket.

I'm in just to find out what you find out. Let us know what it is (was).
 

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First off, it would not be a short, or you would blow fuses, or there would be sparks. So, it is an open, or a bad ground. It is something that is going to require troubleshooting with a meter. You will only be able to troubleshoot the problem when it is happening, so the timing of the occurrence will be critical to your solving it. Intermittent issues are the toughest to fix.


The assistance I can give is to hook up your meter, and start shaking wires and wiggling ground connections. The one clue is that it seems to be global in nature. I would start with the cleaning battery ground, and hot lead. Then check the cables for corrosion at the connectors.
Great advice. I tried searching for a link to all ground locations, but haven't the same tenacity I once did.

Aux battery post. Primary electrical system. Fuel tank ground. Trunk ground. These are some I'd focus on, but again and to be sure, tracking down with a meter as Fred suggested will yield best, finite and quickest results.
 

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Discussion Starter #5
Thanks. Unfortunately, this one is SO intermittent that I'd have to get incredibly luck to track it down as it's happening. I will try tracking it down with a meter while wiggling things. It's not the ICM. Or if it is, it isn't failing the way it did last time. I don't think it's the coil either since the entire car (lights, radio, everything) dies. It also doesn't seem to be temperature related - it's more random than that. I'll try the above suggestions and see what works out. Thanks.
 

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the under hood fuse box battery connection must be removed and checked. this can melt down and do this . common on 1995 ..
 

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Discussion Starter #7
Thanks. This is a '96. I did look at that today, though. The post looks fine and wiggling it and the cable connecting to it didn't have any effect. I do think the issue may be in the underhood distribution center, though. Pulling fuse 11 (60 amp maxi fuse labeled body 2) reproduces the exact same symptoms. I installed Gary's electric WP harness a few weeks back and had the distribution center apart. At the time, I had to fix an unrelated issue with the wiring for the fuel pump fuse. It may very well be that I stressed the wires going to fuse 11 while I was in there or inadvertently caused a different issue.
 

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When mine did that a few years ago, it turned out to be the ground cable to the battery. It had no visible problems. but once I replaced it I have never had the problem again. It was exactly the same problem, total loss of power while driving and I was lucky enough to coast into a parking lot. You have been around here long enough that I doubt you have a zinc ABP :) just for fun, try replacing the cable with a known good one and see if the problem continues. Good luck.
 

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Discussion Starter #10 (Edited)
As far as I can tell from the FSM, the only ground that would cause this issue is the main one from the battery to the body or to the block. All the others seem to handle smaller subsets of items. The ground strap at the driver side cylinder head seems to be fine, as does the ground cable from the battery to the block but I'll check again. The cables are Gary's heavy duty ones, though they're years and years old by now.

This morning while I was checking out the underhood distribution center, I discovered that the positive cable going to the auxiliary post was a little loose - enough for me to move the cable easily but not enough that it seemed to be losing contact. It's possible that I loosened it up yesterday moving things around but I doubt I loosened it this much. It was barely finger tight. Wiggling it didn't seem to affect continuity to the fuse but I tightened it up and am kind of hoping that I found the issue. So...what are the odds it was that simple?

ETA: The battery ground cable connection at the block (behind the alternator brace) is nice and tight. I know it's clean because I cleaned it very well when I installed my electric water pump harness a month or two ago.
 

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Be sure to check out the 3 or 4 Ground wires on the Front of the Driver Cylinder Head near the Coil. Pretty sure the ABS is grounded thru there among many other things. Pull each "Ringed" wire off the post, clean and inspect them for a solid connection to the wire itself. I had one of these pull off the ring and cause all kinds of issues and had to re-crimp a new ring terminal on the wire. Clean each side of the metal ring and coat them with some dielectric grease.

Also when switching over to Gary's cables, found a need to upgrade the Fender ground. His wire is so rigid that the sheet metal screw/star washer setup would not hold well. Converted that over to a Nutsert/bolt setup and can really since down on the heavy wire. It sounds like you've done a good job rechecking your Grounds off the Battery when you replaced yours. As for the chaffing of the ground wire, I wouldn't sweat anything shorting out since its ground, but would be sure to recheck your routing/security of those wires to make sure nothing "does" happen.
 

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you did mess with the under hood fuse box so that is why I said to check that battery feed wire to it . that must be very snug. a lot of current flow there. fans/fuel pump uses a lot of current as well as the injectors.

I would remove that connection and make it shine ... then snug it down...

also the engine block ground at the driver side head should be removed and wire brushed ..

aftermarket wiring is something I just don't see quality IMO....
 

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aftermarket wiring is something I just don't see quality IMO....
Hope you don't mean Gary's cables. His stuff is Better than OEM.
 

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Hope you don't mean Gary's cables. His stuff is Better than OEM.
perhaps Gary had a bad day or the person installing these messed up .

never seen gary's work . when I make up high power cables I will solder the lugs and crimp then heat shrink . no corrosion never will loosen max current flow no resistance over time. IF I need to do a cable repair .. or modify some install ..
 

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Discussion Starter #15
Thanks. Those are helpful suggestions. The connections at the block and fender (ground) and ABP (positive) are all clean and tight and I rerouted the main ground wire yesterday. I also wrapped the chafed part with electrical tape, again, and then sealed it with some heavy duty, submersion-rated heat shrink. I redid the ground at the front of the cylinder several years ago for exctly those reasons. It looks good but I'll keep an eye on it.
 

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perhaps Gary had a bad day or the person installing these messed up .

never seen gary's work . when I make up high power cables I will solder the lugs and crimp then heat shrink . no corrosion never will loosen max current flow no resistance over time. IF I need to do a cable repair .. or modify some install ..
Seems doubtful that Erik missed anything as he mentioned he has rechecked the setup/connections already. I also doubt Gary had a bad day but it is possible, but if you look at what Erik posted, he's had these cables for a while so doubt "bad day" craftsmanship would show up years later.

If you are not familiar with his stuff, then check out his website, here is a link to his Battery Cables....

Caprice / Impala SS / Roadmaster | Innovative Wiring LLC

....and they are a thing of beauty. The Material and attention to detail (like all of his products) are 2nd to None. He even offers customization in Top and Side Post cables depending on your needs. Sure certain aftermarket stuff for our cars can be Crap, but I can assure you Gary's products are not even in the same League as that junk.



Thanks. Those are helpful suggestions. The connections at the block and fender (ground) and ABP (positive) are all clean and tight and I rerouted the main ground wire yesterday. I also wrapped the chafed part with electrical tape, again, and then sealed it with some heavy duty, submersion-rated heat shrink. I redid the ground at the front of the cylinder several years ago for exctly those reasons. It looks good but I'll keep an eye on it.
Good call on getting it covered better. Just be sure to check those ring terminals really well. Hopefully the problem doesn't turn up again but it would have been nice to actually see a failure. I hate it when you move things around and not sure what "fixed" the issue and have to worry if it will show up again at the worst time. Like miles from home on Vacation....been there done that. :frown2:
 

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Discussion Starter #18
Gary makes very nice stuff and he's a good guy on top of that. At this point, I'm using his battery cables, water pump harness and fan relay setup. All are terrific. The only issues I've ever had were operator error and he's been very helpful when I had questions. I can't recommend him enough.

So far so good on the drive in to work. 40 miles and no sign of any issues at all - no flickering of any dash lights and no loss of power. I'm pretty hopeful that tightening the connection at the ABP did the trick but, yeah, I really would be more confident if I'd seen something more obviously broken and fixed it.
 

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Gary makes very nice stuff and he's a good guy on top of that. At this point, I'm using his battery cables, water pump harness and fan relay setup. All are terrific. The only issues I've ever had were operator error and he's been very helpful when I had questions. I can't recommend him enough.

So far so good on the drive in to work. 40 miles and no sign of any issues at all - no flickering of any dash lights and no loss of power. I'm pretty hopeful that tightening the connection at the ABP did the trick but, yeah, I really would be more confident if I'd seen something more obviously broken and fixed it.
since you did find loose connections and then secured them then you now know what happened since you did drive 40 miles with no issues. high current low voltage systems require a perfect solid connection .
 
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