'98 XJ Buzzing Under Dash

So, I've had my "new" XJ for a couple of days, '98 Sport, 4.0L AW4 NP231. The turn signal won't "flash" when I activate it, but the lights come on steady. I searched here, found out that the fuse in the passneger kick-panel controls the flasher and rear defrost. Check the fuse, it's fine. A further search here reveals that the flasher unit behind the knee panel below and outboard of the steering wheel is a multi-function relay for both flasher and rear defrost. I replaced it last night, turn signals work now, rear defrost still doesn't. Also, the new flasher now frequently emits a buzzing sound, which goes away when I use the turn signals.

What I got from the other searched threads is that it could possibly be a bad ground in one of the turn signal bulbs, particularly the front ones. I'll clean those sockets out tonight when I get home. What about the lack of rear defrost? Could it be that I have a bad flasher unit, even though it's new? And why is the flasher buzzing? I'm thinking something else must be up, but chasing electrical gremlins has never been my strong suit.

Thanks in advance.

Doug

buzzing could be the relay contacts intermittently making contact - if you have a marginal ground that could definitely explain this. Sounds to me like an intermittent connection somewhere in whatever provides the ground to the module when the turn signals are not in use, since using the turn signals makes it stop, probably by providing a more stable ground.

1000 percent positive the buzzing is coming from the flasher? Should be one or more warning buzzers/chime module under the dash.

Use a piece of vinyl tubing stick one end in your ear and then move the other end around under the dash to try and isolate where the sound is coming from.

I'm positive it's the new flasher relay that's buzzing. I grabbed it and shook it (knee panel is still off until I get this squared-away) and felt it vibrating, it stops sometimes when I shake it. So a bad ground somewhere else then, eh? Where should I start with that? I'm planning on removing and cleaning the bulb sockets at all four corners today, any idea where the flasher unit grounds? I assume one of the wires in that harness goes to ground somewhere, I suppose I'll stand on my head and see if I can chase it down. What about the lack of rear defrost? Anything else I should look at related to that, besides just buying another relay?


How come I have more electrical problems in the first week of owning my '98 than I did in 14 years of owning my '91?

:banghead:

It could also be an intermittent connection anywhere else related to the flashers - the fact that it goes away when you use the flashers tends to indicate a power/ground to me though. I'll have to look at my schematics later tonight and see if I can find any other possible wiring failures that would cause this.

Alright, thanks kastein. I'll be chasing bulb socket connections and the harness from the flasher unit this afternoon. I'm waiting for the airbag to deploy as I'm messing around with under-dash wiring.