All electrical power dies intermittently - HELP?!?

[Ozz]

Greetings,
My Marauder has an electrical gremlin that I am hoping you guys can help me diagnose.

In the past, I'd hear a click under the dash and my radio and clock would shut off for a few seconds and then come back on.... it appeared that the clock display was always a little dim after this started happening.

Today I shut off the car and heard a buzz from under the dash. It lasted 3 seconds or so and then it stopped. I turned the key and the whole electrical system was dead. No dash lights, no interior lights, no power what so ever. I made a couple of calls to try to get a tow truck and heard the buzz again. I turned the key and viola - the car was back to normal. The clock and radio settings were reset but other than that, back to normal.

What could be buzzing under the dash? I have an extra LCM that I can swap in if you think it might help.

A little side info - I wrecked the car a year and a half ago - extrememe front left. The wire harness was compromised which caused my AC, overhead console and power steering to go dead intermittently. I got that fixed last summer. Could this be the fender wire shorting and causing a surge? Are there any circuit breakers that automatically reset in the dash? That's the only thing I can think of since none of the fuses are blown when this happens and all function came back after the second buzz sound.

[W4LTD]

I am NO expert, but it sounds like it may be a grounding issue...

[Zack]

...or the fusible link has unfused, starter connection loose, battery terminal loose.

[justbob]

Ignition switch?

[Ozz]

I hate to think of doing this but I may have to take the fender wire harness out and go through it to make sure all the wires are in good condition. I was lucky last time in that the insurance company paid for it to be fixed but I doubt they'd pay twice.

I may try to get a replacement harness at a junk yard or something before doing anything else.

Thanks

[omarauder]

I hate to think of doing this but I may have to take the fender wire harness out and go through it to make sure all the wires are in good condition. I was lucky last time in that the insurance company paid for it to be fixed but I doubt they'd pay twice.

I may try to get a replacement harness at a junk yard or something before doing anything else.

Thanks

Sounds like a lot of work, but I would definately check over your "compromised wiring harness" repair for shorts, opens, etc as well as color codes on the individual wires (orange wire to orange wire, etc).

[babbage]

I'd look at grounds too - Add another ground to your neg terminal.

[magindat]

There is no SURGE in automotive DC unless the voltage regulator fails - and that's AC!

[Black_Noise]

If your losing power, check the power.

Start at your battery, check the posts, and the cables, and follow the power wire to the fuse box, skim across the tops of the fuses with a old bulb style test light and make sure you have power on both sides of all fuses.

other than that.... Id have to start thinking about it harder

[Ozz]

I'm thinking it's more of a short since something under the dash buzzes before the power shuts off.... some sort of relay that cuts power when it gets hot or something.

Regarding the wire harness - does anyone know where to get one? The production part number is 3W7T-14290-P or -V. I have a 300A so I assume it would be the earlier 'P' version.

Anyone know of any 300A's that are being torn down for parts? I may post something in the classifieds.

Thanks.

[Glockafella]

sounds like me at WOT...joking...The Lidio Tune does make the headlights dim slightly at WOT, fun fun fun

[rayjay]

When you fixed the wiring after the wreck did you address the chaffing issue at the firewall that some have had?

[Ozz]

When you fixed the wiring after the wreck did you address the chaffing issue at the firewall that some have had?

Tell me more.... the dealership fixed the wire harness so I doubt they did anything about non-accident related problems. Does the chaffing occur on the main harness (14290) that goes from the fuse box behind the battery, to the headlights and around to the firewall on the left side?

Thanks.

[fastblackmerc]

Tell me more.... the dealership fixed the wire harness so I doubt they did anything about non-accident related problems. Does the chaffing occur on the main harness (14290) that goes from the fuse box behind the battery, to the headlights and around to the firewall on the left side?

Thanks.

Use the search function. There is a post with pictures I believe.

[rayjay]

Ozz, I've read about the issue, but do not remember the details. It should come up with a search.

[Ozz]

Well all electrical died again last night when I picked up my kids at daycare. My wife was unavailable to come get them so I had no choice but to start trying to diagnose the problem right then and there.... I lifted the hood and checked the + battery terminal. It was tight as expected. I then checked the - terminal.... it was completely loose.... I wiggled it to the point where it was snug (no tools with me) and checked - power was back on. I tightened it when I got home.

The last time the battery was unhooked was when the wire harness was fixed by the dealership - last summer.... Assuming the problem is now gone - it's safe to say that they left it loose. I'm sure I didn't do it since i always unhook the + terminal and leave the - terminal tight when working on the car.

Thanks for all the suggestions - especially about checking ground. I'm crossing my fingers that the problem is now solved.

THANKS!!!