Headlights dim when I apply the brakes and fuse blows? HELP
Posted 23 August 2012 - 02:53 PM
Alright so I have a 88 Comanche with 2.5 with 4 speed 2wd no ac,ps,pw,pd nothing! Just a base model Comanche. I have recently installed the 99 Cherokee front end and when I turn on my lights they all come on and work fine but when I start driving and apply the brakes the headlights will dim slightly and my parking light fuse will blow? And my gauge light shuts off and all my running lights shut off? Brake lights, headlights, and blinkers all still work?
Posted 23 August 2012 - 03:16 PM
88 MJ Pioneer 4X4 SWB - April 2013 MJOTM - 4.0, AX-15, NP242, D30 + E-Locker / D44 + Aussie, 4.11 gears, 31s, 1.5'' lift
88 MJ Pioneer RWD SWB - Sold
89 MJ Pioneer RWD SWB - My Brother's MJ - 4.0, AW4, D35, 3.07 gears
05 Jeep Grand Cherokee - Sold
08 Dodge Charger R/T R&T - Sold
11 Ford Fusion Hybrid - DD, 2.5L Hybrid
Axial SCX-10 Comanche - My 1:10 Scale Comanche Project
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Posted 09 September 2012 - 08:34 PM
'87 Comanche converted to 4x4 4.0L AW4 NP242, lifted 5 1/2", 33/9.50/15 tires, upgraded brake booster, 90 wiring harness and open cooling system. Tilt, column shift, bench seat, extended front bumper with front tow hooks (room for hidden hitch), canopy, recent new rear bumper 3500lb pull $3500 Good reliable daily driver
Posted 09 September 2012 - 10:09 PM
I think I would begin by removing ALL the light bulbs in the front -- the headlights, parking lights, and side markers. Then try stepping on the brake and see if the fuse blows. It probably will, but -- if not -- replace one bulb at a time until it blows, and that will tell you what circuit to trace.
Since shorts typically occur upstream of devices (light bulbs, in this case), the above may not show you anything. If not, then the next step is to unplug the connectors feeding each light bulb from the harness. Step on the brakes. Hoefully no blown fuse. If that works, plug in one light at a time until you find the one that causes a blown fuse, then trace that circuit.
Self-appointed President for Life of the International MJ Preservation Society
1987 MJ Pioneer 4.0L 5-speed
1988 MJ Chief 4.0L 5-speed
1988 MJ SporTruck 2.5L 4-speed
XJs -- "A few"
Posted 03 November 2012 - 08:24 AM
( ive put a higher amp fuse in for the time being, and it still dims but doesn't blow fuse so thats how I've been driving it)