86 Cherokee. Need desperate electrical help!!!! plz

I was driving my Studebaker pickup down the Blue Ridge Parkway one very dark foggy night and without any warning the lights went out.

The next few minutes were very exciting.

Turns out that modern halogen lights and 45 year old electrical systems don't play nice together.

Funny thought, once everything got straightened out that truck has the best lights of anything I've driven, including my Jeep!

Jeff DeWitt

Earle Hort> I have a Physics degree, I studied Electrical Engineering for four years in

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Reply to
Jeff DeWitt
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That could be the reason for the melted wire at the light switch on his, but not the blowing fuse...

Mike

Jeff DeWitt wrote:

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Reply to
Mike Romain

Even with the Radio Harness off and the wires taped up. It still pops a fuse!!!!!!!!!!!! So does anyone have any other suggestions??? Could over amping the circuit like this asshole did by 5 amps, have anything to do with it? I've come to the conculsion that the wiring is toast, shit the whole piece of crap jeep is toast, but sadly its the only thing I have to work with. I mean lets face wiring in a radio isn't rocket science. I know what the constent 12v is I know what the accesory 12v switch is, I know what wires go where. I didn't just stick wires together. As I stated previous the radio was wired and when I drove the vehicle from College about 30-35 minutes away the radio was PLUGGED in and sitting on the passenger seat playing cd's, it was just not mounted into the dash. I know most of you guys are trying to help and I really really appreciate it, I'm just losing it I'm pissed off when I wake up and I'm pissed off when I go to bed. Not to mention if and when I ever sort out this problem I still have to contend with a Ripped air intake, from the box to the throttle body, A leaking Auto Transmission that could either be the pan gasket or what looked like a busted up Trans-cool line that some asshole fixed with a piece of rubber hose and radiator clamps, a new raditator, the front driveshaft has a CV style joint that the boots been pushed in and more then likely the guts have been containmented so that has to be pulled apart and checked and repacked with grease.

I'm sorry all if I come across as an asshole, but all this from what is suppose to be a daily driver vehicle.

I think I've lost it plain old and simple.

Dave

Reply to
Dave G

You need to go back to stage 1.....

It worked when you got it......

Something you 'fixed' wasn't broken. It didn't just up and short out.

'You' might know how to wire a stereo, but the last person or several people ago maybe didn't know how. Hence the cut wires.

Having the radio sitting on the seat running means dick. It is getting power. PUTTING IT IN THE DASH ADDED ANOTHER GROUND PATH FOR A SHORT! Also a place to pinch a wire when they slide into the dash.

YOU NEED TO REMOVE IT AND REMOVE 'ALL' THE WIRES GOING TO IT AND THE CUT WIRES YOU 'FIXED!

(sorry for shouting, but you don't seem to get it. It worked on the seat is all you keep saying, so you therefore think it must work in the dash. Wrong.)

Is it now impossible to go back to stage 1 because you have forgotten what you fixed or taped up?

You messed with wires on the headlight switch too right?

I mean come on, it is one circuit. It blows fuses. Over fusing something 'shouldn't' have caused a short.

Adding a bad radio is a common short path. The radio can act as a major body ground which blows fuses if you are lucky and/or cooks the radio. This is called ground theft and happens because the wire mesh strap from the firewall to the engine or the cable from the battery to the fender is rotted or dirty. By putting the radio in, you make a new ground circuit so it doesn't have to steal it through the gas or brake pedal any more.

Please answer the questions posed instead of ranting on. I know you are pissed, but some of us here have actually rewired Jeeps.

Did you remove 'all' the light bulbs from the park light circuit? You can remove the 5A dash lights fuse as well to cut that out of the circuit.

The bulbs are known to short out for the signals and running lights sometimes. The glass falls out of it's base and the wires short.

The 10 amp fuse that blows should have the parking lights, the tail lamps, the headlight warning chime/buzzer and the instrument panel dimmer switch on it.

The chime/buzzer module is a rectangle box plugged into the top center of the fuse panel above the flasher. You could pull that out.

You can remove the fuse that blows and put the multimeter set on 20 volts across the fuse socket or you could put a test light there. With a short, you will read 12.2 volts or so and/or the light will light up. Wiggle harnesses and remove light bulbs until it reads 0 volts.

You can also do this with the meter set on continuity or ohms. You hook it to the side of the fuse that leads to the lights, not the power side (find out which with the meter set on 20 volts) and pull bulbs until it stops beeping or take the fuse out and put the meter back on that blue wire that beeped before and then pull bulbs until it stops beeping. When it stops, you have found the location of the shorted bulb or wire section.

Also just to note. Because the radio was killing the battery and you 'wired it correctly' the short happening for 25 minutes might have overloaded the headlight switch's parking circuit. You might need to remove the switch and see if it looks melted down.

Mike

86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail >
Reply to
Mike Romain

You guys are making me *almost* nostalgic about my old 1966 MGB that used to regularly drop all lights on the commute between Moab to Green River...in the middle of the freakin night after a long delay in a missle launch. Wonder what brit engineer thought it was a good idea to route the high current portions of the wiring right behind the front grille where the tiniest sharp pebble would always get caught and cause a short to the positive ground. Or created those voltage regulators that guaranteed your twin 6 volt batteries behind the seats would boil acid all over the unprotected metal carriers. Or the electrical fuel pump would decide to short internally. Or put wires to driving lights that were never standard equipment where those wires would get pinched and short non-relayed high current to ground.

Jeff DeWitt proclaimed:

Reply to
Lon

Damn man, I have rewired more than on MGB and a couple Austin Mini's, plus an old 66 Rover 2000TC. Had the damn battery blow up in my face because of that regulator on the Rover. It had boiled the battery hard on a highway run and I needed to disconnect the battery at night due to some short drawing it down. Likely the regulator thinking back on it... LOL! (sold the car before I ever did find that short) Pulled the battery cable and Bam off comes the top of the battery. Pieces sliced up my eyebrow and cheek and punched right through the hood. Good thing I was real close to water....

Jeeps aren't 'supposed' to act like those nightmares.....

Mike

86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail >
Reply to
Mike Romain

Do I take it (since you didn't mention it) that you actually had an MGB that ... wait for it ... didn't let the rain in ? [gasp]

Dave Milne, Scotland '91 Grand Wagoneer, '99 TJ

Reply to
Dave Milne

There wasn't all that much rain in the high Utah desert, but oddly enough I never got that much rain...granted I had an aftermarket top with the sorta gasket-flange at the windows and a thickened gasket like area at the button downs.

Dave Milne proclaimed:

Reply to
Lon

The ones I saw could even keep out the snow, but man you think a CJ7 is cold in the winter....

Mike

86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail >
Reply to
Mike Romain

Not to forget the parts that would just fall off as you drove down the road..

Reply to
billy ray

With the harness disconnected and all the wires taped up, from the radio. (the wires are not connected to anyting, not even the radio harness.) with all the bulbs out and I mean park lights tail lights side marker lights and turn signals, and with the chime/buzzer module out and the 5 amp instrument fuse out, and the instrument panel off, it still blows a fuse the instant you turn on the headlight switch. So its practicly back to the way I got it minus ( the dash still tore apart and all the kick panels off and the panels under neath the steering colum.) I just don't get it, it has to be a dead short somewhere. I'm lost........

Thanks for the help

Dave

Reply to
Dave G

The method given below will find a shorted bulb, but not necessarily a shorted wire section or socket. Over fusing can cause a short, or exacerbate an existing short, by melting insulation and causing conductors to touch. This is a nightmare, because it will cause symptoms that just don't make sense, and necessitate taking apart the harness to find the wires that are shorted together. Nobody likes a fused-solid harness, where one cannot even separate different strands of wiring or determine which color is which. I am not saying that this is the case with this vehicle, but it will be, and soon, if you don't start tracing wires and finding the fault, as Mike recommends.

It takes some skill and experience to find a fault in wiring that is all wrapped up, using just an Ohm meter. (I have decided that Ohm should be capitalized. It is a proper name. So are Volt and Ampere.) But you can always unwrap the harness and look for physical signs of damage. You should probably do this anyway.

Earle

Mike Roma> I think you need to stop and go back to the basics.

Reply to
Earle Horton

What a piss off eh....

I will take a guess that the headlight switch itself has melted down internally then. I would be removing it and testing it.

Headlight switches do melt down internally. This can be from halogen lights with no relay or even from an extra 25 amp feed on the park light circuit.

I recently melted down my 'new in 2000' headlight switch. Just from running replacement 'normal, not high powered' halogen headlights without a relay. My 86 CJ7's switch was designed for 'normal' GE headlights, not halogen.

Oh... There was one cut black wire you mentioned 're-connecting'.....

Mike

86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail >
Reply to
Mike Romain

I pulled the headlight switch and it looked fine but I replaced it since it was only 11 bucks, to no luck. Tommorrow I'm taking it back to the guy I got it from, he said he would give me a hand in looking for it. I'll let ya all know how it goes.

Dave

Reply to
Dave G

Well guys I found IT!!!!!!!!!

I just first off want to say thank you to all those who helped out (Mike I espically thank you for being patient with a noobie to electronics.) . Here is what it was the back lincese plate wire melted down and was causing the short. So even with the bulb pulled out it was still shorting out. We found this after we tore apart the back liftgate. Un-plugged it and BOOM all my markers and interior lights kicked back on like clock work : ) So it had nothing to do with the Radio. Well I just wanted to fill you guys in.

Thanks again I can finally get a good nights rest.

Sincerely

Dave

Reply to
Dave G

Reply to
L.W.(Bill) Hughes III

Wow... That is just plain nasty and unusual. You are persistent at least.

Mike

Dave G wrote:

Reply to
Mike Romain

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