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cj7 electrical nightmare

961 views 9 replies 6 participants last post by  dylan0708 
#1 ·
alright heres the story i bought an 84 cj7 this is my first rebuild and im to the last phase... rewiring and electrical... alright now i labled everything to what i thought was the best of my capabilities and now i have hooked it all back up again and when i turn the key the engine will turn over and start no problem.. however when i turn the lights on the left blinker will stay on and the high beam button will not work... i do not have the tail lights or head lights or blinker actually hooked up but the lights on the dash are what stay on also the oil preasure guage and voltage lights along with the speedo lights do not turn on... during this process i lost two wires that go to the rpm guage and the clock. one thing i noticed was when the key is turned on and you touch the possitive wire to the battery terminal there is an odd ticking sound... and last but not least the fan inside will not turn on... any help will be greatly appretiated i have no idea what to do its a mess and i dont understand where i went wrong
 
#2 ·
If your tach is not plugged into the wiring harness you will not have power to the ignition. For now just plug the two wires for the tach together and run it that way until you can find your wiring for the tach. The tach is wired in series with the ignition so without it no power to the coil or module.
 
#3 ·
It sounds as though you have several different issues.

I hate to say it but you'll need to go back and double check all your connections. Double check your grounds, especially at the engine. Make sure the ground strap is installed at the engine mount and ensure the battery ground to engine block is clean and good.

Remember that the dash lights all get their ground through the speedometer.

The ticking sound you hear is most likely a chattering relay, which is an indication of a poor connection.

Why was all the wiring disconnected in the first place?
 
#5 ·
It sounds as though you have several different issues.

I hate to say it but you'll need to go back and double check all your connections. Double check your grounds, especially at the engine. Make sure the ground strap is installed at the engine mount and ensure the battery ground to engine block is clean and good.

Remember that the dash lights all get their ground through the speedometer.

The ticking sound you hear is most likely a chattering relay, which is an indication of a poor connection.

Why was all the wiring disconnected in the first place?
I had all of the wires out because I stripped the whole jeep for a frame up resto... I noticed when I bought the jeep however there was a major ground going to the passenger side motor mount and it had been cut but all the electrical in the jeep had been working before...
 
#7 ·
JOHN STRENK IS YOUR MAN!
User John Strenk has some GREAT posts about chasing the gremlins out of your wiring, and he has the best graphics/tutorials I've ever seen for this.

If you have specific questions, post them up and we'll try to help, but contacting John Strenk and searching is old posts is the best start for you.
 
#8 ·
Dylan, the negative cable to the frame is usual, but then you need a ground strap from the frame to the block, maybe a few, because the motor mounts are rubber and may be insulated.

If you have ever done wiring on a trailer you would know the answer. When ever the lights go bonkers, left turn signal and the right flashes, turn signal both lights flash, etc. it is BAD GROUND.

My son started his V6 for a V8 swap this weekend and melted the small ground strap off the battery to the core support. A little grinder action where the negative cable bolts to the frame and a ground strap from the frame to the block and he was cooking with gas.

Only a bad ground can screw things up royally. The current starts going backwards with unpredictible results. Sorry but you are going to have to scratch that shiney paint on the frame;-)
 
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