Dash light fuse blows every time I use headlight switch

[bc4lyphe]

I bought a TJ build 9/98, I'm guessing its MY 1999? 4.0 5 speed. Been going through it and fixing all the small issues.

It has an aftermarket stereo and the PO installed a new headlight switch. I put a new ignition switch in it. The heater blower switch doesnt work on High.

I found that if I have the stereo on and turn on the headlights, stereo turns off. Also if I have the stereo on and crank it up, eventually the odometer will blink when the "bass" hits, and if I turn the volume up more, itll shut off the stereo. I figured bad ground. Also to note, when the headlights were on the dash dimmer lights worked fine.

I found the stereo ground behind the dash and connected it to the back of the stereo. Now I can use both headlights and stereo at the same time and I can crank the volume without having the odo blink or shutting the stereo off. Now however the dash cluster lights arent working. I found the 10amp dash light fuse behind the glovebox blown. It blows every time I use the headlight switch, both marker lights (1st click) and headlights (2nd click).

Any ideas?

 

[q8ieng]

I bought a TJ build 9/98, I'm guessing its MY 1999? 4.0 5 speed. Been going through it and fixing all the small issues.

It has an aftermarket stereo and the PO installed a new headlight switch. I put a new ignition switch in it. The heater blower switch doesnt work on High.

I found that if I have the stereo on and turn on the headlights, stereo turns off. Also if I have the stereo on and crank it up, eventually the odometer will blink when the "bass" hits, and if I turn the volume up more, itll shut off the stereo. I figured bad ground. Also to note, when the headlights were on the dash dimmer lights worked fine.

I found the stereo ground behind the dash and connected it to the back of the stereo. Now I can use both headlights and stereo at the same time and I can crank the volume without having the odo blink or shutting the stereo off. Now however the dash cluster lights arent working. I found the 10amp dash light fuse behind the glovebox blown. It blows every time I use the headlight switch, both marker lights (1st click) and headlights (2nd click).

Any ideas?

Hello!

1- The heater blower switch doesn't work on high, it is either the AC switch panel on the dash is not working properly or the Blower Motor resistor, I have been in this before.

2- Check the stereo wiring, I do believe the wiring needs a rework.

 

[Flivver250]

Remove all of the wiring from the PO and start fresh from scratch. I pulled out miles of crappy wiring that some maniac did in the past and installed the accessory wires correctly fused with relays where needed and tapped into correct circuitry. An idiot with a spool of electrical tape does not always make a low voltage electrician. My Jeep was lucky it hadn't burned to the ground. Usually if your fan does not work on lower speeds, it is the resistor. It may be the switch, but do not be surprised if you end up replacing both. I would, just because they are both common failures after 15-20 years. May as well get it over with. I did the blower motor as well.

 

[Goatman]

Stereo/headlights sound like they have power in common too. The TJ has some odd wiring that makes the power side of a light sometimes act as the ground side for the marker lights, which change polarity when blinking which causes the LEDs you installed not work right. Or something close to that.
So, like said above, yank all the wiring the PO did. It is obviously fu@ked up. And rewire everything either back to stock, or on it's own dedicated circuit to prevent problems like this cropping up again.

 

[bc4lyphe]

Oh right on guys. The extra wiring was actually pretty decent and uncluttered. There was a relay to run hi/lo horns which was fused, and a fused switch under the dash to run some HiLites on the A pillars. I looked at the stereo wiring and at first glance it looked pretty good but then I noticed they had run the Black ground wire from the Alpine into the factory Orange which I looked up to be the Illumination.

I did end up take the blower switch apart and it looked like the center conductor was just concaved a bit and not making contact with the 4 speed wires. Bent it out and its working now. Ordered a new one for later.

I pulled the door switches out and set those to work properly. and popped a fuse in.

Other than the back door not locking and having to adjust the 4x4 linkage I think Ive got it all back to her former glory! Looking forward to hitting the trail soon.

 

[Flivver250]

Nobody gets off that easy!

 

[Goatman]

Sometimes people do...just not me. I always seem to get the ball buster of a fix.