Wiring melt under dash

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89er
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Wiring melt under dash

Post by 89er »

How much trouble am I in with this rats nest on a scale 1 - 10? 1 being easy fix, 10 being a living nightmare. The only things currently not working on the Jeep to my knowledge are Air Conditioner, Heater, and Cruise Control. Where do I even start?

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'89 Grand Wagoneer Baltic-blue/Tan
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tgreese
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Re: Wiring melt under dash

Post by tgreese »

Snip out the burnt wires and splice in new. Just go one wire at a time, and don't be overwhelmed.

There was a reason for the melted wire. An '89 probably has specific places to look first - someone here that knows more about the last years of GW will comment.
Tim Reese
Maine beekeeper's truck: '77 J10 LWB, 258/T15/D20/3.54 bone stock, low options (delete radio), PS/PDB, hubcaps.
Browless and proud: '82 J20 360/T18/NP208/3.73, Destination A/Ts, 7600 GVWR
Copper Polly: '75 CJ-6, 304/T15, PS, BFG KM2s, soft top
GTI without the badges: '95 VW Golf Sport 2000cc 2D
Dual Everything: '15 Chryco Jeep Cherokee KL Trailhawk, ECO Green
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fulsizjeep
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Re: Wiring melt under dash

Post by fulsizjeep »

I had this happen on my 88 when the original choke wire landed and melted on the right side engine header. It is ugly but repairable.
Flint Boardman
88 GW, 401/727/208, 5" lift, D44s/4.10s/locked up, 35s
https://jubileejeeps.org/quadratrac
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fulsizjeep
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Re: Wiring melt under dash

Post by fulsizjeep »

If I remember right, I found that the choke power does not go through a fused circuit. That red choke wire melted against other wires in the loom all the way back to the ignition switch.
Flint Boardman
88 GW, 401/727/208, 5" lift, D44s/4.10s/locked up, 35s
https://jubileejeeps.org/quadratrac
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89er
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Re: Wiring melt under dash

Post by 89er »

Good advice folks thank you. Doesn't seem as nightmarish as it did looking at it last night.
'89 Grand Wagoneer Baltic-blue/Tan

letank
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Re: Wiring melt under dash

Post by letank »

Remember to disconnect the battery when you start the surgery...
IIRC that yellow wire is used on the ignition circuit
Michel
74 wag (349 Kmiles... parked, next step is a rust free body)
85 Gwag (229 Kmiles... the running test lab)
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babywag
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Re: Wiring melt under dash

Post by babywag »

fulsizjeep wrote:I had this happen on my 88 when the original choke wire landed and melted on the right side engine header. It is ugly but repairable.
Got my dad's '90 GW badly with emissions/choke wire short.
Destroyed a lot of engine harness and also the under dash harness. Really really stupid circuit design!!!
Real PITA to repair due to how many wires it melted.
-Tony
'88 GW (aka Babywag)

candymancan
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Re: Wiring melt under dash

Post by candymancan »

Is this the choke wire on the electric choke passenger side of the carb with the flat female connector ? Mine was dissconected years ago and laying on the intake manifold and i plugged it back in.. I guess it was disconnected by falling off and this is how it shorts and causes fires right ?


Or do i still have the wrong wire you guys are talking about lol.. can you maybe post a pic of this wire in the engine bay for me plz ? Id like to add a fuse to it before it causes problems lol
1998 Jeep Grand Cherokee 5.9L Limited 219k
1998 Jeep Grand Cherokee 4.0 I6 laredo 430k
1990 Jeep Grand Wagoneer 155k
1976 Jeep J10.. 85k(repaired)
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89er
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Re: Wiring melt under dash

Post by 89er »

An update for anyone interested:
I unbolted the bulkhead last week to find the blackened (charred perhaps) chunky rubbery grease all in and around the connectors that needs to be cleaned out, waiting for WD40 electronic cleaner to come in the mail still. The bolt to take apart the bulkhead is in the engine compartment hidden in the center of the bulkhead amidst all the wires.

Then inside the cabin there is 2 torx bolts on diagonal ends that hold in the Fuse box. I needed topside access so instrument panel also needed to be removed, just a few philips head screws and unplugging the speedometer cable and stuff from the back side.


Image

2 previously orange wires were clearly what started the meltdown as can be seen at the bottom here. I just deleted what was left of them and slowly repairing what I can. It's been a learning experience.
Image

I'm somewhat confident I can repair the 15 or so melted wires that remain. I'm less confident I can put all this BEEP back together once the time comes. Perhaps just a confidence issue.
'89 Grand Wagoneer Baltic-blue/Tan

dbabicky
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Re: Wiring melt under dash

Post by dbabicky »

I'm not even giving my !975 J-10 a chance to burn down. Come Spring it'll get a new 21 circuit wiring harness from BJ's and a Holley Sniper EFI. She's parked with the battery disconnected until Spring !! The Holley Sniper EFI has nothing to do with the fire hazard type harness, just thought it would be a nice upgrade. Had a Howell set-up on my 1981 CJ-5 with a 304 V-8. Absolutely loved it.

1979bettywhite
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Re: Wiring melt under dash

Post by 1979bettywhite »

I think you can do it no problem. Just take your time and exercise patience. Don't rush and try to get it back together quick. I have had to develop confidence in many of the tasks I have completed on the chief along the way. It might take me twice as long as someone with experience, but I get to learn and feel that sense of accomplishment when I am done.

You planning to solder or crimp connections? Good heat shrink is nice to use as well.
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89er
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Re: Wiring melt under dash

Post by 89er »

1979bettywhite wrote:I think you can do it no problem. Just take your time and exercise patience. Don't rush and try to get it back together quick. I have had to develop confidence in many of the tasks I have completed on the chief along the way. It might take me twice as long as someone with experience, but I get to learn and feel that sense of accomplishment when I am done.

You planning to solder or crimp connections? Good heat shrink is nice to use as well.

Thanks for the vote of confidence. I'm definitely using soldering and heat shrink. The issue I'm running in to is that I suck at soldering and the connection ends up fatter than the wire so I'm using larger than necessary heat-shrink tubing and it does great shrinking to the soldered part but doesnt fully shrink to the wire, particularly on the 18ga wires, so its a little loose at the ends and im having to wrap them with electrical tape. Getting a little better at it with each wire.

Would love to take a month to make sure its all ironed out perfectly but I saw Theodores thread (http://www.fsjnetwork.com/forum/viewtop ... 15&t=15857) with a fresh cut Christmas tree on his GW and I MUST do the same. Need to knock this out. Didn't get a chance to work on wiring yesterday because new fuel filter and (teamgrandwag) oil dipstick/tube came in and it took me an hour just to get the dipstick tube to go in at the correct angle.
'89 Grand Wagoneer Baltic-blue/Tan

letank
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Re: Wiring melt under dash

Post by letank »

thank you for posting, so we know if we give the right suggestions. As for putting it back together, as long as the wires are still pliable you should be good. The black goo is the dielectric grease used at the plant.

you can make it, as for soldering, better iron, hotter is better, but you need to act faster, put the solder on the contact and the iron on top... Or a good crimper.

ALSO, the main issue is that you do not know why the wires melted, so restoring the circuit to its original combo is good, but the problem may still be present... Orange is USUALLY related to lighting dash to courtesy to overhead... recheck the wiring diagram of your vehicle year, 89 is a bit different than others. Lower left when looking at the fuses is more of a heater fan fuse
Michel
74 wag (349 Kmiles... parked, next step is a rust free body)
85 Gwag (229 Kmiles... the running test lab)
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tgreese
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Re: Wiring melt under dash

Post by tgreese »

What kind of soldering iron? What kind of solder? Brand, composition, diameter?

The joint should be hot enough that the solder flows in when you touch the solder to the joint. If the solder blobs up, you are soldering at too low a temperature. You have to be fast so that the joint heats up to soldering temperature before you melt the wire insulation next to the joint.

I suggest adhesive-lined heat shrink, and uninsulated butt connectors. Crimp, then solder, then heat-shrink. A little extra flux can be helpful.

https://www.delcity.net/store/Non!Insul ... 0.h_801871

https://www.parts-express.com/search.as ... PortalID=1
Tim Reese
Maine beekeeper's truck: '77 J10 LWB, 258/T15/D20/3.54 bone stock, low options (delete radio), PS/PDB, hubcaps.
Browless and proud: '82 J20 360/T18/NP208/3.73, Destination A/Ts, 7600 GVWR
Copper Polly: '75 CJ-6, 304/T15, PS, BFG KM2s, soft top
GTI without the badges: '95 VW Golf Sport 2000cc 2D
Dual Everything: '15 Chryco Jeep Cherokee KL Trailhawk, ECO Green
Blockchain the vote.
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89er
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Re: Wiring melt under dash

Post by 89er »

tgreese wrote:What kind of soldering iron? What kind of solder? Brand, composition, diameter?

The joint should be hot enough that the solder flows in when you touch the solder to the joint. If the solder blobs up, you are soldering at too low a temperature. You have to be fast so that the joint heats up to soldering temperature before you melt the wire insulation next to the joint.

I suggest adhesive-lined heat shrink, and uninsulated butt connectors. Crimp, then solder, then heat-shrink. A little extra flux can be helpful.

https://www.delcity.net/store/Non!Insul ... 0.h_801871

https://www.parts-express.com/search.as ... PortalID=1

This is great advice. I will absolutely be getting some adhesive lined heat shrink tubing, not real satisfied with the cheap tubing I bought. I'll have to check on the solder, I think is just a rather thick lead free electrical solder.
I'm using the Power Probe micro torch, which has been excellent so far but I don't have much to compare it to. The shield for heatshrink that protects other wires is ace.

Image
https://www.amazon.com/Power-Probe-MTKI ... B01LTHHP8W
'89 Grand Wagoneer Baltic-blue/Tan

letank
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Re: Wiring melt under dash

Post by letank »

I took a peek at the 89 wiring, it is in the Haynes, and the orange for the 89 seems to be for 1) the electric choke control that is below the exhaust manifold, 2) idle speed solenoid, 3) the carburetor vent, and NO fuse on that circuit
Michel
74 wag (349 Kmiles... parked, next step is a rust free body)
85 Gwag (229 Kmiles... the running test lab)
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tgreese
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Re: Wiring melt under dash

Post by tgreese »

Proper flux for electrical and electronic - https://www.amazon.com/d/Soldering-Flux ... ering+flux The proper solder has a flux core, which is plenty for bright new metal. If you are soldering old car wires, a little extra flux will help. Apply flux to prepared joint, warm the joint so it melts in, then solder normally.

Good solder for car wiring - https://www.amazon.com/Kester-24-6337-0 ... er+63%2F37 - 63/37 is a "eutectic" alloy of tin and lead. 60/40 is fine too, though its melting point is slightly higher.
Tim Reese
Maine beekeeper's truck: '77 J10 LWB, 258/T15/D20/3.54 bone stock, low options (delete radio), PS/PDB, hubcaps.
Browless and proud: '82 J20 360/T18/NP208/3.73, Destination A/Ts, 7600 GVWR
Copper Polly: '75 CJ-6, 304/T15, PS, BFG KM2s, soft top
GTI without the badges: '95 VW Golf Sport 2000cc 2D
Dual Everything: '15 Chryco Jeep Cherokee KL Trailhawk, ECO Green
Blockchain the vote.
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89er
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Re: Wiring melt under dash

Post by 89er »

letank wrote:I took a peek at the 89 wiring, it is in the Haynes, and the orange for the 89 seems to be for 1) the electric choke control that is below the exhaust manifold, 2) idle speed solenoid, 3) the carburetor vent, and NO fuse on that circuit

Oh sweet, any chance you could upload a pic of that page?

I've been going off the electric FSM, the 2 14OR at the bottom left were my problem. Is any of that stuff (electric choke, idle speed solenoid, carb vent) worth me reconnecting new wires?
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'89 Grand Wagoneer Baltic-blue/Tan
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tgreese
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Re: Wiring melt under dash

Post by tgreese »

Should be labelled as connection/wire 12 on the wiring diagram. The 14OR means it's an orange 14 ga wire. There are two of them going to connection 12.

http://oljeep.com/gw/elec/89GW_elec/198 ... System.jpg

B6 should be the bulkhead connector location, though I don't know where that will show up. Maybe on the connector itself, though you may need intense light and magnification if you can find it.

Whether you keep these depends on your plans for the Jeep. If you keep the factory carburetor, you need to power the electric (actually 'thermoelectric') choke. The bowl vent solenoid closes the float bowl vent to prevent escape of fumes from the carburetor when not running. The carburetor solenoid (idle stop solenoid) closes the throttle plates tight when you shut off the ignition to prevent run-on (a guess, but pretty sure that's right).
Last edited by tgreese on Tue Dec 04, 2018 1:37 pm, edited 1 time in total.
Tim Reese
Maine beekeeper's truck: '77 J10 LWB, 258/T15/D20/3.54 bone stock, low options (delete radio), PS/PDB, hubcaps.
Browless and proud: '82 J20 360/T18/NP208/3.73, Destination A/Ts, 7600 GVWR
Copper Polly: '75 CJ-6, 304/T15, PS, BFG KM2s, soft top
GTI without the badges: '95 VW Golf Sport 2000cc 2D
Dual Everything: '15 Chryco Jeep Cherokee KL Trailhawk, ECO Green
Blockchain the vote.
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89er
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Re: Wiring melt under dash

Post by 89er »

tgreese wrote:Should be labelled as connection/wire 12 on the wiring diagram. The 14OR means it's an orange 14 ga wire. There are two of them going to connection 12.

http://oljeep.com/gw/elec/89GW_elec/198 ... System.jpg

B6 should be the bulkhead connector location, though I don't know where that will show up. Maybe on the connector itself, though you may need intense light and magnification if you can find it.
Excellent, I had no idea what that first number was before the color/gauge number. Makes a lot more sense now. Pretty sure this chart is the cabin side of the bulkhead connector showing where that B6 would be. Concerned about B5 14orange AC clutch feed. Thats gonna be critical to getting the AC up and going I would think.

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'89 Grand Wagoneer Baltic-blue/Tan
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