Ignition control wiring problem, '89 Cherokee
#1
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Year: 1989
Model: Cherokee
Engine: 4L six
Ignition control wiring problem, '89 Cherokee
An issue has returned that I discussed here two years ago: https://www.cherokeeforum.com/f2/sym...ailure-203912/
The problem was that the control wire connections into the ICM had "corroded" or more accurately, burned out. I fixed it by acquiring a replacement ICM and pigtail from a wrecking yard.
Two years on, same problem, so now we know something is wrong that causes the control wire connections to overheat. For 25 years there was no problem, but now it's returned after 2.
I'll try and interpret wiring diagrams for clues but can anyone point me to a source for this connector? The wrecking yard won't let me have it, they now only sell the entire harness.
The problem was that the control wire connections into the ICM had "corroded" or more accurately, burned out. I fixed it by acquiring a replacement ICM and pigtail from a wrecking yard.
Two years on, same problem, so now we know something is wrong that causes the control wire connections to overheat. For 25 years there was no problem, but now it's returned after 2.
I'll try and interpret wiring diagrams for clues but can anyone point me to a source for this connector? The wrecking yard won't let me have it, they now only sell the entire harness.
#2
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Year: 90,84
Model: Cherokee
Engine: 4.0,2.5
Could the coil primary be shorting and drawing way to much current, but still work?
Given time I could "McGiver" about any connection, there has got to be a way. Agreed, I have two of those with more than 25 years on them that are fine. IIRC the coil primary resistance is about Zip, pole to pole. Suspicious that it's grounding.....
Given time I could "McGiver" about any connection, there has got to be a way. Agreed, I have two of those with more than 25 years on them that are fine. IIRC the coil primary resistance is about Zip, pole to pole. Suspicious that it's grounding.....
#3
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Year: 1989
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I replaced the coil two years ago because I couldn't remove the melted connector from the original. When two parts behave exactly the same way I can't suspect them of being the problem. Something outside the ICM is causing too much current to go to GND (the center connection, the only one to burn out).
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Year: 90,84
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Engine: 4.0,2.5
Well..I've got to drop back and punt...A longtime mantra of mine, "If it's Goofy and makes no sense, suspect grounds" Cruiser here on the forum couldn't agree more I'm sure. 89 has no C-101 connector, but whatever is left on tips 1 trough 5 probably would be smart. Maybe something else is looking for ground back through there? (that wire does go other places besides ground I'd assume)
Lot's ground through the ECM or TCM which have their own grounds. My guess is things are not grounded directly to prevent damage from missilainous mischief. (like hooking jumper cables up backwards).
"Something outside the ICM is causing too much current to go to GND"
Voltage is kin to water pressure, pushing electrons through things. With normal system voltage it's only a matter of how much resistance there is. A "short" is kin to opening a valve or having a broken pipe.
Boy, got me. Does seem way lot's of current went through that. Check all the other grounds is about all I have.
onlyjeepparts.com has a phone # They might have the connector.
Lot's ground through the ECM or TCM which have their own grounds. My guess is things are not grounded directly to prevent damage from missilainous mischief. (like hooking jumper cables up backwards).
"Something outside the ICM is causing too much current to go to GND"
Voltage is kin to water pressure, pushing electrons through things. With normal system voltage it's only a matter of how much resistance there is. A "short" is kin to opening a valve or having a broken pipe.
Boy, got me. Does seem way lot's of current went through that. Check all the other grounds is about all I have.
onlyjeepparts.com has a phone # They might have the connector.
Last edited by DFlintstone; 01-31-2017 at 03:12 AM.
#5
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Year: 1990
Model: Cherokee (XJ)
Engine: 4.0
How was the JY harness attached to the original?
Soldered? Shoulda been.
Ever done this?
http://cruiser54.com/?p=41
I would do Tips 1,3,4, and 5 if it were me.
Soldered? Shoulda been.
Ever done this?
http://cruiser54.com/?p=41
I would do Tips 1,3,4, and 5 if it were me.
#6
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Year: 1989
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Wow. I looked over the wiring diagram and saw how many devices were grounded at the dipstick mounting bracket and thought, hmm, maybe that's coming loose. So I looked and it was so buried in grease I thought rather than get all filthy reconnecting something that's been tight since 1989 I'll .... etc. Obviously owning an old Jeep is not for the lazy. Thanks for the Cruiser54 site! Great stuff there.
#7
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Year: 1990
Model: Cherokee (XJ)
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Just as a reminder to folks how many things ground at that dipstick tube stud, click on the link below.
http://cruiser54.com/?p=19
http://cruiser54.com/?p=19
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#10
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The ones used on our early XJs are GM Weather Pack connectors (Delphi, Delco, and so forth) and are readily available online and at good parts stores. You can also order the pigtails pre-made up instead of the individual pins, seals and connectors if you don't possess the tools to make them up. The green one is specific to the GM-style MAP sensors that we have-- notice the 2 orientated notches on the outer circular pin guides? My '87 uses standard black connectors if I recall correctly. I have a few spares for making up new ones, or adding wiring for accessories.
For examples:
https://www.amazon.com/Delphi-Packar...1W4ZH88XK8XDQ0
or
https://www.amazon.com/OLS-3-Wire-We...therpack+3+pin
vs
https://www.amazon.com/Map-Sensor-Ha...sensor+pigtail
For examples:
https://www.amazon.com/Delphi-Packar...1W4ZH88XK8XDQ0
or
https://www.amazon.com/OLS-3-Wire-We...therpack+3+pin
vs
https://www.amazon.com/Map-Sensor-Ha...sensor+pigtail
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Year: 90,84
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It isn't all that easy to photo ether! Better to really clean every surface. Once I just loosened the nut and sprayed cleaner through, jiggled things, repeat a few times. Better to really clean every surface though. A hard film can happen that that process will not work on.
Last edited by DFlintstone; 01-31-2017 at 03:25 AM.