Electrical gremlins? Gauges & aftermarket radio

98 XJ with about 145K. Kenwood KDC-X994 head unit has been in for 6 months with no problems, hooked up to two amps, one for highs, one for a sub.

So I was driving back from D.C. to Richmond today, about a 2 hour trek, when I had all types of weird electrical problems going on.

First, the radio cut out for a second, then turned back on with no issues. Almost like it reset itself. A few minutes later, the radio went dead, and all the dash gauges went dead too. Every gauge went to zero, except the speedo which kind of just fell to the 6 o'clock position, all while I was driving down I-95. Pulled over and checked out the fuses in the PDC, noticed one of the 15AMP mini fuses was blown. Replaced it and the new fuse immediately went, battery was still connected but the vehicle was off. Went over to AutoZone, got a pack of replacement fuses, replaced the blown fuse and all was well.

Then the radio started exhibiting all types of weird behavior. Shutting off when driving over potholes. The highs would cut out, or just the sub would cut out. Turning off the radio then turning it back on would remedy that. Then the radio died and so did all the gauges again. Replaced the fuse, gauges work, but the radio is still exhibiting strange behavior.

I think it's fairly obvious that the radio needs replacing, but do you think it would cause the fuse that controls the gauges to blow? The radio has fuses built into it, you would think those would blow before the underhood one would if there was some type of short. I checked the radio ground and the engine and battery grounds and everything looks fine. Any suggestions?

Have you pulled the radio out and looked at all the wiring for shorts?

I was hoping not to revive this thread, but low and behold.

For the past week everything had been fine, the radio was working perfectly, no fuse blown.

I ran into problems yesterday on the way back from work. Was driving along, nothing crazy, didn't hit any bumps, but out of nowhere the radio and gauges go out. Replaced the *I think* #16 fuse in the PDC, immediately blew, then just drove home w/o radio and gauges. (see pic)



Pulled the radio out, checked the wiring harness for shorts, couldn't find anything in particular. Replaced the PDC fuse again. Fuse blows again on the way to work this morning.

A few other things I've noticed. With the fuse blown and no keys in the ignition, the power locks will unlock, but will not lock, activating the switch to lock the doors results in nothing. If I put turn the key to the ON position, the locks work perfectly fine.

This XJ has a DEI alarm with an LCD display, the kind that tells you if the door was opened or the hood or the hatch or if a window was broken, etc. When I activate the alarm it does work, but it takes a little longer than usual and states that the door was opened when the alarm was on, even though that's not the case. Not sure if this is just a coincidence because the #16 fuse is blown.

Anyways, I know that I'm gonna have to trace back some wiring to find the short in the system. Unfortunately, I do not have a wiring diagram for a 98, I have one for a 2000 but the PDC is different in that year. From what I could find by searching that fuse is connected to all the gauges, the dome lights, and the radio. Anyone have any tips on finding the little bastard causing the shorts without tearing apart the entire dash and interior?

There is a ground strap that go's from the back of the engine block to the fire wall. Should be braided. Check to make sure that is not loose or damaged. That was my problem when the same thing happened to me.