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Electrical Another burned up dimmer switch

Electrical Another burned up dimmer switch

TSB8C

Old Time Jeeper
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Cut-n-Shoot, TX
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1984 CJ7, 420 HP "ZZ6 EFI" Crate engine, 700R4, D300, Dana30 front, Dana489 rear, 4.56 gears, 4" lift
This seems a common issue for CJ's - the floor mounted dimmer switch burns up and/or the socket along with it. My headlights (prior to LED conversion) quit working and tracing the wiring I discovered that the dimmer switch had a burned center prong and the socket connector had partially melted. Now we all know that these old CJ's had some inferior wiring for some circuits, and this appears to be one of those areas. So I decided to do a mod to this wiring that removed the high current draw of the headlight bulbs away from this headlight switch and dimmer switch wiring and instead move it to some relays in a separate fuse box. Now the headlight switch and dimmer switch merely activate the low current draw relays instead. Now I later upgraded to LED lights (headlights and turn signals both), so this may be a moot point since those draw lower current. But I still like the mod and thought others might as well.

First off was a new headlight switch (Crown # J5751098) and a new dimmer switch (Crown # J5461816). I also needed the dimmer switch electrical socket connector (AC Delco # 89581YB). Next comes the fun part. Locate the two power wires for the headlights where they come out of the junction block on the driver side firewall (one wire for low beams and one for high beams). See the pic below for the connections. Cut these two wires. Now connect up two relays, one for high beam and one for low. Connect the wires you just cut from the junction block to pin 86 (one on each of the relays). Connect the other end of the wires you cut (going out to the headlights) to pin 87 on the relays (be sure to connect low and high to the right relays). Now connect a direct wire back to your battery (through a fuse) to pin 30 on each relay. Then simply ground pin 85 on each relay. Each relay should now have 4 wires on it: fused power from the battery on pin 30, output power to the headlights from pin 87, activation power from the junction block on pin 86, and ground on pin 85. Now when you switch on the headlights and use the dimmer, you are actually applying 12V to the activation coil on the relays (one at a time depending on low or high beam selected on the dimmer switch). These relay activation coils only draw about 1 amp of current through your headlight and dimmer switch wiring. Nowhere near the 10 amps or so two halogen headlamp bulbs would draw. The power for the headlights is actually coming straight from your battery (through a fuse you hopefully installed) and the relays (normally capable of 30 amps each).

Even if you're not experiencing burned wiring or electrical connectors, many report brighter lights when doing this mod as well. So may be a great choice and it's easy and cheap to do. And who doesn't like modding something else on their Jeep just for the fun of it?

fusebox_firewall_side.webp Headlight_Relays.webp
 
There are a few companies that make harnesses for this. I installed one from Speedway Motors.
Those after market harnesses certainly make it easier. But with just two cheap relays and some wire, it's a very simply mod that takes about an hour. In my case, I had already installed a secondary fuse/relay box to handle the fuses and relays for the front/rear spot lights, onboard air compressor, and aux power outlets. So I used two of the relays and one fuse slot in that box for this headlight mod. Just cut and spliced a few wires and presto.
 
Expect more issues as Crown is China made junk
 
Expect more issues as Crown is China made junk
Hopefully this mod and the switch to LEDs has greatly reduced the strain on the electrical components. I've also replaced all dash lights/indicators and under dash courtesy lights with LEDs as well. So the headlight switch really handles verry little current anymore at all. But you do echo a common perception of Crown's quality (or lack thereof).
 
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IIRC the OEM hi/lo beam switch was made by Delco.
Gary
 
Interestingly earlier this year a class action law suit was filed alleging that GM falsely claims their AC Delco line is made in the US when in fact it is also made in China. Not sure how that suit ended up. But I do know there is a difference between their "AC Delco Professional" and "AC Delco Genuine Parts" lines. I've never seen a Jeep headlight or dimmer switch as part of their "Professional" line of parts. If the "cheaper" line is indeed made in China, you're probably getting the same level qualify of item as Crown sells - maybe even made in the same Chinese plant, but packaged in a different box. Oh well, cheap and easy enough to replace again if necessary some years down the road.
 
I went to buy an ACDelco fuel filter/regulator at O’R…. and paid over 100 bucks. I returned it because it was made in Taiwan and instead got their knock off brand for less than 30 bucks. Guess what, it was the EXACT same unit in a different package. The clerk just said that I was just paying for the brand! At least he was honest.

On another note, what does it take on a CJ to bring the dimming function up to the turn signal lever…Anyone?
 
I went to buy an ACDelco fuel filter/regulator at O’R…. and paid over 100 bucks. I returned it because it was made in Taiwan and instead got their knock off brand for less than 30 bucks. Guess what, it was the EXACT same unit in a different package. The clerk just said that I was just paying for the brand! At least he was honest.

On another note, what does it take on a CJ to bring the dimming function up to the turn signal lever…Anyone?
I'm guessing your talking about your 68 CJ. You would have to change over to a GM type column.
 
CJ, it’s for my 82 daily driver. These have GM columns as we all know. You might be referring to a column from a newer Chevy vehicle…
 

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