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Electrical Headlights inop

Electrical Headlights inop
Vikingone

Vikingone

Senior Jeeper
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Location
Lake Worth FL
Vehicle(s)
85' CJ7, 4.2 Liter, swapped in T18
About to go through and troubleshoot why my headlights don’t work. I’m not the best at reading wiring diagrams so I was wondering if there are some main things I need to be aware of. Are there certain grounds I should watch out for? I did notice that the wiring to my dimmer switch has wires broken off.


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I'd start with the switch it self they go bad and usually take wires with them

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The factory wiring routes all headlight power they the dimmer switch, so if you have wires broken there, that would be your problem. Most of it at least. Seriously consider a relay setup for your headlights - they run brighter, and redirects the heavy load away from the headlight switch and dimmer switch, increasing reliability of both.


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I'd start with the dimmer switch pull the plug and look for corrosion.
 
The headlight wiring is probably the easiest to follow. Red wire (power) to the dimmer switch. Gray wire and gray wire with trace. Gray to headlight (low beam) drivers side, splice and across grill to pass side low beam. Gray with trace (high beam) same route as low beam. Head light connector has three slots with wire Gray,gray with trace and black.The black one is the ground, usually leads to a screw on a rusty grill. Clean that up for sure. Make sure your grill is grounded. Turn signals are grounded to the grill as well.

How much rust you have will affect ground. The grill is grounded via the fender bolts to the grill which is grounded via the tub to fender bolts. The tub is grounded via the frame to tub bolts IIRC. Frame is grounded by web strap to the engine block. Grounds are the biggest culprit of electrical things. Sounds like a pretty hokie way of grounding. When things get rusty, ground goes away.

If your dimmer connector needs to be replaced, you can get a new one here and do some splicing. https://www.repairconnector.com/products/Dimmer-Switch-Connector-for-Ford-Chrysler-AMC-3-Leads.html
Looks like it is out of stock, if you can't wait or find one somewhere else. the other GM Ford connector will work fine.

As all have said, dimmer switch is generally a problem. New ones are $10 or so. Found out why my lights would only work sometimes when I got irritated and kicked the dimmer switch and lights came on.

Best thing is to do what shum8 suggested and use relays.
 
shum8 said:
The factory wiring routes all headlight power they the dimmer switch, so if you have wires broken there, that would be your problem. Most of it at least. Seriously consider a relay setup for your headlights - they run brighter, and redirects the heavy load away from the headlight switch and dimmer switch, increasing reliability of both.


Sent from right here.......
Click to expand...

Not sure how that is done. I’d like to do it though.


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yellow85cj said:
The headlight wiring is probably the easiest to follow. Red wire (power) to the dimmer switch. Gray wire and gray wire with trace. Gray to headlight (low beam) drivers side, splice and across grill to pass side low beam. Gray with trace (high beam) same route as low beam. Head light connector has three slots with wire Gray,gray with trace and black.The black one is the ground, usually leads to a screw on a rusty grill. Clean that up for sure. Make sure your grill is grounded. Turn signals are grounded to the grill as well.

How much rust you have will affect ground. The grill is grounded via the fender bolts to the grill which is grounded via the tub to fender bolts. The tub is grounded via the frame to tub bolts IIRC. Frame is grounded by web strap to the engine block. Grounds are the biggest culprit of electrical things. Sounds like a pretty hokie way of grounding. When things get rusty, ground goes away.

If your dimmer connector needs to be replaced, you can get a new one here and do some splicing. https://www.repairconnector.com/products/Dimmer-Switch-Connector-for-Ford-Chrysler-AMC-3-Leads.html
Looks like it is out of stock, if you can't wait or find one somewhere else. the other GM Ford connector will work fine.

As all have said, dimmer switch is generally a problem. New ones are $10 or so. Found out why my lights would only work sometimes when I got irritated and kicked the dimmer switch and lights came on.

Best thing is to do what shum8 suggested and use relays.
Click to expand...

I bought a new dimmer switch last night. I was just gonna sure it myself without a connector. Just have to find out what post is which on the switch.


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Vikingone said:
Not sure how that is done. I’d like to do it though.


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Click to expand...

It’s not difficult - gathering the bits and pieces is harder than actually doing the work. Because I am lazy - wait - LAZY, I found a harness already made up and was plug and play. The guy making up the harnesses has since stopped, but I’ll dig around and find the write up for you


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Hey your not Lazy. Your just getting warmed up. When you decide to get going you roll. :chug: When you take over for that guy that quit I would like a set. :banana:
 
The original member that started making the plug and play relay harness offered to us was Jimbos76cj. He stopped making them but has a few threads on here dealing with the harnesses. This is the first post he made inquiring about our interest in the harnesses: https://jeep-cj.com/community/threa...-pre-made-head-light-upgrade-harnesses.19110/

I installed one of his harnesses on my '76 CJ5 in 2013 and it is still working great. Best lighting upgrade you can do for an old CJ (IMHO).
 
hdgapeach said:
The original member that started making the plug and play relay harness offered to us was Jimbos76cj. He stopped making them but has a few threads on here dealing with the harnesses. This is the first post he made inquiring about our interest in the harnesses: https://jeep-cj.com/community/threa...-pre-made-head-light-upgrade-harnesses.19110/

I installed one of his harnesses on my '76 CJ5 in 2013 and it is still working great. Best lighting upgrade you can do for an old CJ (IMHO).
Click to expand...

Yup - That’s where mine came from as well. One of the few visible differences I know of.....


Sent from right here.......
 
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