2nd Gen Non-Engine/Transmission Bad electrical ground? Or???

[Ncostello]

The 1999 3500 4x4 at works has an issue as of today. When you turn on the hazzard blinking lights... the dash lights and the radio lights blink as well. Mechanics are assuming the batteries are "bad"... to which I called them lazy and nothing but parts installers. They didn't like that. Truck starts and runs fine otherwise.



My thinking is a bad ground somewhere. Is there a "main" ground to the dash wiring of these trucks? I'll check it out myself on Saturday when nobody is around to bother me.



I once had a 99 Mopar manual... but sold it several years ago. So no luck there.

 

[mwilson]

Only on Hazard??? Could be a crossed filament in a bulb, front or rear. Also if it has a 7-way trailer plug look in there and see if the green goo is crossing the terminals.



Also maybe find a few new techs, "BATTERIES" ???????? Come on.

 

[barryg41]

I could send you the pdf for the wiring diagram for the whole truck, if you want it. I would need a email addy because its over 3megs.

 

[Ncostello]

Yes... only in Hazzard to my knowledge. But I've yet to check it myself. Often what the drivers say, then what the mechanics tell me... its like that game kids play where you repeat something around a circle of people. At the end its pretty dis-con-bobulated from the original statement. Let me check to see first... the shop may have the OE manual as well. I think I remember seeing it on a dusty shelf. Obviously... they've never used it. But thank you!!



It does have a 7 pin trailer connection... that gets wet alot and hit with salt. And from what I remember seeing... the wiring to the tail lights (HD truck style, cause its a dump body) looked to be in poor shape. Maybe a cross there somehow. I will definately check the trailer connection.

 

[Bob Cochran]

Even blown fuses sometimes causes weird back feeds at times. I was playing with the trailer plug and blew a fuse. I cannot honestly remember which one(I think would not have expected it to be blown based on what it was labeled) but it caused the fog lights to light dim when they where not turned on. Just something else to check and yea bad grounds to weird stuff too.

Usually check fuses first, grounds second, then get out schemes and really get to work!!!

 

[Ncostello]

Lucky me. After some visual inspection and testing... it turned out to be quite simple. The left rear tail/stop/turn bulb had a filament out and it was touching the tail lamp filament. So when the hazzards were on it was "back feeding" the tail lamp circuit... and thus also the dash instrument lights. Also did it with the brakes. These aren't the pickup bed tail light assemblies... but rather the typical semi truck combo lamp housings with a dual filament bulb. I call them Jeep lights.



We haven't had them out at night in recent weeks so we never noticed a burned out tail lamp.



Glad this didn't turn into an electrical nightmare!!!

 

[SRath]

Make sure you pass that info along to those mechanics; it will separate the merely ignorant and inexperienced from the lazy and stupid.



Nice call, MWilson!

 

[DieselDoghouse]

Nice detective work "Watson"... I was about to suggest pulling all the directional bulbs as next step. Comes from my (posted)experience when the left turn signal would launch the wipers!!! Yes, chide the mechanics, but most are sorely unschooled in electronics-I blame their instructors!! What a wonderful digital age we live in (suffer in?). Somebody hand me a VOM-I need to check for an offset voltage!!

 

[Bob Cochran]

Good deal glad it is solved.

Lucky me. After some visual inspection and testing... it turned out to be quite simple. The left rear tail/stop/turn bulb had a filament out and it was touching the tail lamp filament. So when the hazzards were on it was "back feeding" the tail lamp circuit... and thus also the dash instrument lights. Also did it with the brakes. These aren't the pickup bed tail light assemblies... but rather the typical semi truck combo lamp housings with a dual filament bulb. I call them Jeep lights.



We haven't had them out at night in recent weeks so we never noticed a burned out tail lamp.



Glad this didn't turn into an electrical nightmare!!!

 

[DODGEDADDIE]

I have a battary drain going on,,2 new 1000amps,,that go dead in 2-3 days. . !!!??,

Nothing is on,,any ideas on WHERE TO START?





THANKS

Mike In Maine

 

[SRath]

You don't have any info posted on what year your truck is, but that is a serious drain. FYI: the headlight switches in these trucks has been known to short out and literally burn them to the ground. I'd be checking. Mine has melted down twice before I made my own relay harness for the trailer lights.

 

[mwilson]

As mentioned above, we need to know what your truck is... .



If it has a glovebox light check that first, that will kill a charge in 2-3 days, seen that kill many a battery.



If not, do a search on here. There are detailed procedures for locating a current draw written by some clever guys regarding the use of a multi-tester. You will have to start isolating circuits until you find the culprit.



Patience is the key, don't panic and start cutting/hacking as I have seen some people do.



If you have to run the truck and can only troubleshoot when you have a spare minute start unhooking the negative cables when you leave it so that it will fire up and go when needed.



Ask questions as you go, we will help you.



Another Mike in Maine.

 

[jhoughton]

Another area to check as others have posted is the seat belt relay.

 

[DODGEDADDIE]

OOOOOPSS!!!. .

98 ,,,,12 VALVE

With 193,000. . ",,5" exhaust,,370 injectors,,K&N FILTER



MiKe In Maine