91' XJ Electrical Problem

[DDX]

I have been having a few problems with my 91 XJ. Recently, I installed a head unit and 4 speakers, and since then (although im not sure if it was immeadiatly after) I have had problems with electical shorting out. On a 15 amp fuse are my: Tail lamps, parking lights, instrument panel dimmer, and the buzzer that lets me know my lights are on when the car is off adn door is open. I continually blow this fuse, the second I turn the lights on, it blows it. I have checked all the things on the fuse (all the lights and stuff) but cannot find anything that would cause this short. The only thing I havent checked is the buzzer because I cannot find it.

Now, like I said earlier, I dont think its because of the new radio because its on a differnt fuse and works fine, but I cannot think of anything that'd cause this.



Also, my drivers side power window only works about 1/2 of the time, completely randomly, it will go half way down and stop, even if I continue to hold the button. I have checked connections to the switch and theres nothing wrong there.


Anyone help please?

[XJnick]

Hi,

There is one common thing that links the radio and the tail lamp circuit together.... the Illumination Relay circuit. This circuit is responsible for the radio and clock's illumination. When you turn on your headlamps, this circuit is activated, and is probably causing the fuse to blow.

Go back and check and double check that you didn't get any wires crossed when installing the radio. Most aftermarket radios have their own backlighting and don't tap into the Illumination circuit, so be sure that wire is either connected properly or capped so it isn't grounding out.

Hope that helps
-Nick

[DDX]

I took out the radio and tried again, still blew it.

[XJnick]

The problem is most likely in the wiring, not the radio head unit it self.

Try this... The illuminaion relay should be under the driver's side dash by the fuse block. It would be a 5-pin relay. Try unplugging it from it's socket and see what happens. If the fuse continues to blow, the problem is somewhere before the relay or possibly a different circuit. If the fuse stops blowing, the problem is in the relay or somewhere downstream of the relay.

-Nick

[DDX]

Well, in an odd turn of events (It seems the man who is puting up the drywall in my basement was an auto-electrician for 10 years!) he gave me a hand, and in about an hour, we traced it to the back. It seems back there thier is a couple of cables, one male, one female, that are for who knows what, and I thought I disconected them when I put my speakers in, so I connected them after the installation. It appears that was the whole problem.