Diagnostic on Temporarily Dead Electronics (1 Viewer)

[98100Crusher]

Diagnostic question for the group:

Twice in the last month I've gotten into the truck (98 LC with 155k) and turned it over and everything is dead electronically. The first time there was some power that quickly (a second or under) faded out meaning no lights on dash at all, no interior lights and couldn't move shift lever. The battery was six months old and I still had the old one so I replaced it and it fired right back up so I assumed it was bad battery. I replaced the battery and hadn't had until issue until yesterday.

Yesterday I was getting the car inspected of all places, had the car in the inspection bay and jumped back in to back it out when it did the same thing. This time it didn't seem as if there was any power at all. The inspector (its an independent shop who just does inspections) grabbed his jump starter and it fired up on the second or third turn of the key.

I was going over in my head what's different and its rained pretty hard the last few days here(but everything I looked at was bone dry) and when I jumped back into truck I probably turned the key faster than I normally do (I usually give it a 'one one-thousand' count in the second position before turning it over completely).

I've ordered all the fuses and am breaking out the FSM but figured I'd post here too as its my dd. Apologies if I've missed a thread on the topic (I didn't see one where everything was completely dead but then fired back up after a reset).

 

[2001LC]

If your lucky this is and easy fix.

Clean & grease battery post. If post are not greased when cleaned or new they build a thin layer of oxidation that inhibits current/charge. After which you'll need a full charge on battery, either with charger or two hour HWY drive. See what happens.

Two other possibilities come to mind:
1-If unlucky you could have issue in fuse box, issue with security system.
2-Bad alternator.

 

[Eharmz]

Just came to the forum to look up this exact problem I have been having with my 98' with 292k on it. I am wondering if it has anything to do with the trailer brake controller, as the first time it happened the display went all over the place before the car lost all power...It stayed dead for a minute or so and then fired right back up (though the settings on my cd deck were all gone and the clock was wrong, so complete power loss). Second time this happened was yesterday morning when I was leaving for work...nothing, dead....came home from work and it fired up on the second try. This time though it didn't look like a complete power loss as the clock and cd deck still had normal settings. Don't mean to hijack your thread, just hoping more will chime in on possibilities. Will start with the battery terminals and fuse box.

 

[98100Crusher]

fyi - My battery posts were clean and greased.

Intuitively it feels like there's a short/surge in the system where a reset/back off time fixes it. The electronics are nineteen years old so not a shock that normally reliable parts would start to fail. My plan is to start with the fuses and start to inspect and replace components unless it fails again to trace through the system.