1983 Jeep CJ7 coils keep burning up

  • 1983 JEEP CJ7
  • 6 CYL
  • 4WD
  • 197,000 MILES
I have a 1983 jeep cj7 4.2 strait six and my coils keep burning up I have gone through three so far I even tried to install a balist coil resistor to help it but it even burned up what is my problem where is my problem
Thursday, June 3rd, 2010 AT 12:37 AM

1 Reply

  • 11,004 POSTS
OK Boss,

Several things to check :

See if "I" terminal on your SOLENOID is putting out constant 12V instead of 12V when key is in the start position (temp 12V while starting only) I'll give you a "Nelsomatic" Pic----THIS IS MASSIVE OVERKILL--BUT LOOK AT, MAKE SURE YOU ARE SET UP LIKE THISTEST "S" and "I" make sure they do what the diagrams say they should do (MORE STUFF AT BOTTOM)

See my profile. Yours may not look like this, but TAKE STUFF LOOSECLEANTIGHTEN WELLDO NOT JUST PASS IT OFF AS, "it looks good".

Do not leave off where the Battery cables connect to the Battery clamps! (not the posts) Do them too!

While you are at it, Both ends of Pos cable, Both ends of NEG cable.

If you still have the problem, you're probably looking at $20 to replace the SOLENOID. Follow Battery Positive cable to find it.

My stuff may be OVERKILL, but at least you will know what everything is and does.

Like my newly made "NELSOMATIC" stuff? I am cyber stupid, and did that! Keeps me from hunt and pecking so much!

Please Reply, Good or Bad.

I will continue to try to help you through your whole ordeal, even if this didn't help you. Just continue to Reply at "reply to question".

Love, Turddog

Follow POS BATT CABLE, It will end up here, at the SOLENOID, looks vary, function is the same.




Positive cable from battery

2) out to starter motor

3) on my jeep, this goes to the alternator

4) this feeds my fusebox (all of my accessories)

5) "s" wire is from key, 12v only while you are "cranking"

this wire activates the solinoid's electromagnet, which in turn, connects---a & b internally (only the 2 large gauge cables can handle the amperage the starter "pulls").

When the solinoid is activated, it throws 12v to starter using the large gauge cables (1) pos from batt--thru solinoid internal connection--(2) to the starter, while key is in "cranking" mode.

This is the total reason for a solinoid, because it would not be practical, to run the heavy cables to and from your key switch.

6) "i" wire (optional), feeds coil "full 12v", only while "cranking", after you release the key, the coil reverts back to reduced voltage, supplied by your key in the "run" position.

7) "mount" ground, unit must have a good ground (batt. To engine, engine to frame, frame to body [all must connect, somehow] )

(3 & 4, on my jeep) are fusable links, all are not marked, my #3 is, #4 is not....its sort of a "wire" fuse.

If they are good, tugging on them will be just like a wire, when they are "burned up", they will stretch out lke a rubber band.

Unfortunatly your rig is almost as old as my newest! ('77)

people tend to rig up stuff/splice/remove things over the years....

Are you running a coil---external resistor only?

Unfortunatly your rig is almost as old as my newest! ('77)

People tend to rig up stuff/splice/remove things over the years....


The wire from your key (on position) is not all, but partly a RESISTANCE WIRE (just like using a CERAMIC type resistor) UNLESS SMARTY-PANTS GOOFUS removed/replaced/tied into it, years ago

Any wild stuff with the ignition module wires?


Love, Turddog
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Thursday, June 3rd, 2010 AT 5:06 PM

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