Symptoms Of A Dead Time Control Unit
 

Evening all,

I decided to make one last check of everything to make sure my '92 is absolutely ready for inspection this weekend, and I've noticed a few things that are making me believe the Time Control Unit has failed:

Rear wiper doesn't work when switched to intermittent, if switched to "on" and then back off, it stops where it's at and doesn't come back to it's "home" position.

The courtesy lights do not work.

The clock doesn't light up

The rear defogger doesn't seem to work (the light doesn't come on in the switch, and the glass doesn't seem to get warm)

HOWEVER, I looked up the wiring diagram, and the other systems plugged into the thing do work (Auto seat belts, front intermittent wipers, tail lights, and HVAC).

All in all, none of the malfunctions would cause it to fail the inspection, but it would be nice to have the courtesy lights at night, and the rear defogger for in the mornings. Any insight?

Re: Symptoms Of A Dead Time Control Unit
 

Your symptoms are very similar to what I experienced when the time control unit died in my 1995 SVX.

Re: Symptoms Of A Dead Time Control Unit
 

Well, I am an idiot. Okay, I shouldn't be so hard on myself, but really, you'll all get a laugh out of this.
I wanted to make completely sure the Time Control Unit was faulty before digging it out and finding a replacement. I pulled up the wiring diagram and found every fuse that provides power to the sucker and started back tracking the problem. As it turned out, fuse 25 (under the hood) was blown - kinda.
A visual inspection said it was okay, but the test light disagreed with me. Key on, touch one contact to one side and it lights up, touch to the other side and you can see the light's filament glow, but it looks more like an electric stove burner rather than a glowing light. Hmmmm... Replaced with another 10 amp fuse, both terminals lit up, and the clock and dome light works again.
So how did I miss that? Well, I took a close look at the bad fuse and it didn't blow out in the typical fashion - the center piece was intact, but off to the side on the post was just barely disconnected, nothing you'd ever catch by just glancing at it. So yeah, lesson learned - just because a fuse looks good at a glance, it's still better to test it

Re: Symptoms Of A Dead Time Control Unit
 

Good info and nice to know. Thanks.