Electrical problem getting worse. Any help highly appreciated

[Motorhead350]

I finally got my passenger window to work again by swaping the drivers master window switches, but a ton of problems occurred.

1. A/C head unit will sometimes work, mostly does not.

2. Interior lights do not come on at all when opening doors.

3. Power lock switch does not work.

4. Doors UNLOCK when ignition is turned!

5. Radio display will dim. Also radio stays fully lit when headlights are on, but buttons do not light up.

Here is where is get's really funny...

When you hold the unlock button for the doors, the clock will turn on and off on command, interior lights will turn on if the switch is turned on, radio will dim if headlights are on... you can literally get these light to turn on and off with playing with the unlock button.

I put the old lock switch on the "new" junkyard set and the results were the same as with the other switch.

I am hoping this is simply a fuse or circuit that went on while I changed the window motor.

Gauge lights all stay on, radio will always work even with lack of display and windows ALL work all this time now. I highly doubt this is all because of the lock and unlock button, but the button seems to be controlling the function of other electronics now. :eek:

Anyone have a clue as to what is going on or why things only work when I hold down the unlock button?

Also, are master window switches "Marauder specific"? I looked up part numbers on-line and they match, BUT these are only for aftermarket companies so I do not see those websites as a credible source.

[Shaijack]

Dom you have Grimlins. $8.00 for it...

[L.Mark]

I feel your pain big time...I'm still fighting the gremlins that invaded mine about 2 months ago. Nowhere near as peeved off as your gremlins are. Some of my problems went away when I unpluged one of the main connecters under the brake booster, Mike said it was one of or THE main connector to the PCM. Worth a shot and it's free. Hope it helps Dom!!!

[WhatsUpDOHC]

Did the ghost move from the house to the MM?

[fastblackmerc]

Sounds like a grounding issue.

Check all the grounds, especially the one from the right side of the cam cover to the firewall.

[babbage]

Sounds like a grounding issue.

Check all the grounds, especially the one from the right side of the cam cover to the firewall.

+1 ^^^ Any cables got the "green meanies" ?

Add another ground to the negative terminal on your battery (which is how old?)

New Alternator perhaps? Check for a pinched cable, near drivers side head.

[ctrlraven]

Sounds like a grounding issue.

Check all the grounds, especially the one from the right side of the cam cover to the firewall.
This would be my first step as well, the MM seems so very sensitive to power/ground problems. The smallest flux can cause a waterfall effect in one area and that rolls over into another module etc etc. This is why most mechanics hate working on vehicles with electrical issues as they can be very hard to diagnose because it becomes a process of elimination.

Should try doing the big 3 upgrade, it could solve the issues, if not it's still a benefit to the overall electrical system.

[BAD MERC]

Definitely sounds like a ground issue. Ground a test light and probe other metal body structures with it, dash, engine, doors, computers... and if the filament lights up - it's passing ground.

You don't need voltage to illuminate a bulb - making it pass any current will illuminate it - as low as 300 milliamps will cause visible light.

[Spectragod]

Most likely a bad ground or grounds, drive it till you smell smoke......

[Motorhead350]

I had no issues until I missed with the window switches.

I will check the unit by the passenger head too. Thanks guys.

AC works again.

[RF Overlord]

Dom, I thought it was your house that was possessed, not your car...

Try taking the "new" window switches out and see if the the problems go away. If not, talk to your priest.

[Motorhead350]

Dom, I thought it was your house that was possessed, not your car...

Try taking the "new" window switches out and see if the the problems go away. If not, talk to your priest.

Are you sure my issues will go away with things unplugged?

I thought even if they were all good switches, without all electronics connected an issue would occur.

[fastblackmerc]

Are you sure my issues will go away with things unplugged?

I thought even if they were all good switches, without all electronics connected an issue would occur.

Try it.......

[Motorhead350]

Try it.......

I shall later today.

[Motorhead350]

Pulled the master switches and nothing changed, no additional problems neither.

Time to go at the firewall, this will suck.

[WhatsUpDOHC]

I remember reading that the drivetrain is isolated from the frame and that poor grounding of the straps from the drivetrain to the frame cause hard to diagnose electrical issues.

[Motorhead350]

Took out box by firewall, sodered what looked like the issue... problem not fixed.

Grrr

[Motorhead350]

All that's left is to check that little black box by the brake petal.

I have checked ALL fuses and mismatched new and old switches, even simply disconnecting them.

I also gave the battery a try by disconnecting the negative for a few minutes, nothing changed.

One upside to all of this is I found my anti-freeze leak. I hope I can get this done. All I have to do is unplug and replug that little box? Sounds too easy to solve this issue.

[Spectragod]

Sounds like you may want to call someone to locate the bad ground.

[fastblackmerc]

All that's left is to check that little black box by the brake petal.

I have checked ALL fuses and mismatched new and old switches, even simply disconnecting them.

I also gave the battery a try by disconnecting the negative for a few minutes, nothing changed.

One upside to all of this is I found my anti-freeze leak. I hope I can get this done. All I have to do is unplug and replug that little box? Sounds too easy to solve this issue.

Did you check the grounds? Sounds like you didn't.

[babbage]

Yeah Dom did you check the grounds - try adding another ground wire! File metal so its shiney - needs a good contact to conduct.

Dont just check them, pull, file, replace.

[Motorhead350]

LCM appears to be shot.

No gages or tail lights.

Everything else is back to working.