HELP! My BJ almost caught fire

[wesintl]

I was wheeling with treeroot on Red Cone and just finished using the winch and 100 yards down the trail I see white smoke coming from under the hood. I stopped and wouldn't turn off so I stalled it. Popped the hood and the passenger side battery ground to the body completely melted and was on fire. We once throughed everything and the rest of the wires appeared fine. The only acc off the other battery were winch and aux lights. So then I had no power to anything. The edic relay on the passenger footwell was the only thing clicking. We tried to diagnose but didn't conclude anything besides it's probably the fusable link. I was able to get her started and drove home. Thank god for mech diesel.

So I'm gussing I had a good short and blew the fusible link. Hopefully thats the case. Any pointers to find the Fusable link quickly and anything else I should look at? 85 bj70 12v

Thanks all

Wes

[Greg_B]

Yikes! At least you and your truck are in one piece!

I know there was chat on fusible links on the DTLC a while back. Wonder if they are a dealer item still...

Sorry not much help...

gb

[crushers]

the fuseable link is (2?) black wires going from the battery to the small black box about 4" away...
cheers

[wesintl]

That little tiny thing the just connects 2 wires? I doesn't even look like a fus link.

So Far i'm fawked. The negative battery to the body produces 12.78v

The wire coming off the + with the green connector 6" down is the once causing the - to - charge. I guess this is going to be a drawn out major league headache

[crushers]

that woudl be them...

[brownbear]

Ok looking at the wiring diagram. Not sure how your fusible link would cause this. its just a fuse. it supposed to prevent this kinda thing.

but anyhow, this is what I would do. ( disclaimer- just educated kinda guess use info with own judgement)

you must have a serious short to ground. So first with all the battery leads disconnected.
take your mulitmeter and check from the pos battery lead wire to chassis ground. you should not have continuity. if any of the switches or systems like lights are turned to the on posistion you will get a reading thru that system.

in theory you should have no ohms on that meter. now there may be something. but should not be low.

if you have nothing I would then turn the key on and see what you get. cause the short to ground could be thru something ignition related.

if you do get a reading. you can pull fuses to try and see what could be causing it.

basically pull fuses till you hit the one that causes the short.

long shot, but maybe you had a battery do some weird reverse polarity thing. with the battery leads disconnected which pole has what, does the negative show positive polarity??

it looks like two fuseable links for a 1985 70 series and three for 60 series..

so you would have two wires going to it.......? then leaving the links are red and white wires. white going to ignition and red going to hazards and headlights.

also remember your starter is the main power draw from the battery that is not fusible linked. straight wire connection. only the solenoid controls it. not that this could be the problem. but its another wire to disconnect. if it chafted thru you would be welding along the frame.

glow plug relays have done crazy things to me before. I had on that was seriously shorting out. dragged the voltmeter to the bottom. but that way key on, when the power was off I was ok, it didn't keep going.

so thats your big question, is this power on or off that is continuing the melt down?

hope that helps somewhat.

[treerootCO]

I think you should start with the dome light fuse. That is the last possible thing that can cause everything on the truck to stop working!!

[honk]

Is the winch still connected? If it is, and since the melt SEEMS to have happened when you used it, maybe it's shorted or one of it's solenoids are stuck on?

just a thought....

[wesintl]

Many Thanks to Treeroot for helping me get off the trail and get home. I'd do the same for you We started pulling fuses and diagnosing where the lead went but with power to the body everything seemed to power Finally we found that the dome light fuse caused the short in the body to go away. Hooked everything back up and then some with the 7.5 amp fuse for the dome light pulled and everything roared to life.

Now to find out where the short it in the dome light. I dunno if I'll ever know what caused it. My first thought was the winch because we had just used it but it had also started to pour rain at that time so that might have contributed or been the problem. I'll be having fun today. At least I can take it wheeling without using the dome light.

Stupid question on the Fus link. Is that wire supposed to melt or what? I'm used to the old style 40 series fus link that looks like a little box.

Thanks for the tips BB they are always handy for ele diagnosis. Also to the rest of you guys mud comes through again.

Do you guys like that pic from treeroot of the - to body producing light

Wes

[brownbear]

Thats wild the dome light? you would think that if there was short at the dome light, the current draw would have increased and blown out the fuse, or if not the fuse it would have meted the light gauge wire that goes up to the dome light. But not the main heavy gauge chassis ground wire.

keep a wrench and gloves handy to remove the negative post in case it happens again.

[wesintl]

Originally Posted by brownbear

Thats wild the dome light? you would think that if there was short at the dome light, the current draw would have increased and blown out the fuse, or if not the fuse it would have meted the light gauge wire that goes up to the dome light. But not the main heavy gauge chassis ground wire.

That's what blows us away too. no blown fuse or the fus link

unfortunatly I didn't have any dreams last night that revealed the answer and I haven't heard from treeroot either I so I suspect the same

[brownbear]

try a science experiment, take a 14 gauge wire or 16, wire a 7.5 amp fuse in the middle, attach one end to the pos of a battery and the other to the negative. The wire will heat up and melt and or blow the fuse. But that would happen long before a heavier gauge ground wire will even start to get warm.

not saying the dome light isn't the problem.... but before you put the family or dog into the vehicle and go sit in traffic, just something to consider. fires are not fun.

I had a wire from a amp meter on a Corvette burn the entire length from starter to amp meter. pretty gross, it was in a bundle.

something to keep in mind chafted wires or shorts cause a burn mark. like welding. if you can't find the burn mark then the draw isn't enough for melted ground wire.

for that kinda draw its a big item to ground. serious arcing and welding. or stuck on relays, etc.

i hope you have good luck. don't want to park a cruiser too long.....

[wesintl]

I think i found the culprit... Some lazy FAWK that installed the stereo!! that was me Still more work to do though since this was one of the first things to be removed from the battery and we still had draw.

[wesintl]

Well... I'm kinda back to the same issue :(

The EDIC continues to run back and forth while the fuel control relay clicks from + to - (yeah I took it apart) and I don't get anything upon crank (no click etc) I removed the LOP wire from the sensor and no change.

any suggestions?

[Behemoth60]

Originally Posted by wesintl

HELP! My BJ almost caught fire

Almost. ALMOST! Awe, come one. Drop us a line when you get the job done properly.

Try going over a curb in a parking lot, and having the positive side terminal from your un-secured 24V battery make contact with the fuel filter housing, burn a hole through the fuel line, squirt diesel fuel all over your engine, continue the short and ignite said fuel, and keep on driving. I finally found a nice parking spot in the shade, popped the hood, and doused the flames. The only reason I couldn't drive home was because the vacuum hoses from the buttfly valve to the injection pump were melted. Towed it home, replaced the two hoses, and she was driving again within 2 hours. To this day, some 2 years latter, the charred remains of heater hoses, melted brake resevoir, and bare wires with burnt insulation still criss cross under the hood. Sadly. I did have to retire the battery with the melted plastic casing last fall, however, it wasn't becuase the battery was melted... that' for sure!

Originally Posted by wesintl

Well... I'm kinda back to the same issue :(
any suggestions?

I say this ever time someone has intermittent eletciral problems.... Bad ground?
I ran a ground wire from the dash board of tippy to the negative battery terminal and magically fixed a bunch of annoying eletrical problems, including a funky chicken EDIC.

The other problem I've noticed is that the EDIC can do the funky chicken when it is wet. If it got doused on your wheeling trip, try drying it out.

Peter Straub

[Greg_B]

Any progress with this?

gb

[tlcruiserman]

Originally Posted by wesintl

Well... I'm kinda back to the same issue :(

The EDIC continues to run back and forth while the fuel control relay clicks from + to - (yeah I took it apart) and I don't get anything upon crank (no click etc) I removed the LOP wire from the sensor and no change.

any suggestions?

Wes,

I have been parting out an 85 BJ70 so I have a lot of the electrical stuff (my other 70's are all 24volt) still. Let me know if you need anything or want any wires traced, I have the harness pretty much out of the truck.

Cheers,

Michael

[wesintl]

No progress unfortunatly. I'm trying to follow the leads to the steering column but i'm not really anywhere. It wierd i'm back haveing a + charge on the drivers side body/engine side. I can't get anything on the right passenger side.. so I just keep trying to isolate. I just hope that it's not the wire in the harness that won't carry the proper volts. I'm pertty much testing relays etc. per the fsm right now.

Thanks for the encouragement guys. I may have to hit you up for some wires or relays Michael. I appreciate the offer

[wesintl]

ok.. speaking of which do you have the fuel control relay? Anyone know how much it is from the dealer?
maybe even the first geen connector off the + batter (drivers)

I think my batteries might be toast even though they give me 12.78v But I seem to be doing better getting juice from the wifes TDI.

I seem to be having issues with the white wire off the + so i'm trying to trace that.

[wesintl]

Well I toasted the batteries. They showed a good volt but the amps was another story. I think one had 60 cranking amps.. LOL I should have known better and applied the KISS principle. I now have 2 yellow top optima's. So far everything has been running well. I do need to replace the Fusable Link as it's on it's last leg. See other thread.

New batteries sure do turn the engine aweful quick.

Many thanks to all you mudders especially to those offering parts in time of need.

[Greg_B]

Cool, glad you got it figured!

gb