Vmates

Ok, my 93 del sol began quite suddenly having an issue with the dash & running lights. They do not turn off. I work on my own cars and I'm an electronics engineer. So, I checked a few things out and concluded it must be a broken switch on the stalk/steering column. I removed the switch, and decided to disassemble it to see if something was physically broken or if the comtacts were dirty. Hey, the car has 400k miles on it.
The switch was physically fine internally...really simple set of slide contacts. However, the contacts were very dirty. Cleaned it up, reassembled, and dully tested good. Prior to all this I disconnected the battery.
So, I put thr switch back in place and no dice. I was OK with thinking I needed to buy a new switch. Without thinking, I unplugged the switch without disconnecting the battery. And guess what?
The dash/side marker lights still stayed ON. Yup, no switch hooked up and lights on.
I cannot find anything like a dedicated relay for these lights which indicates a simple circuit running through the switch and associated fuses. I've checked both fuse boxes (under dash & engine bay) and fuses are good. Obviously there is a short which bypasses the full off switch position. But I'm not having luck finding where. Has anyone come across this and could provide me with pointers? Is it possible that the problem is in the instrument cluster? Only reason I ask is that over the past year my speedo registers about 1/2 the actual speed I'm traveling. I understand that to be related to dirty contacts on the back of the cluster. But I haven't yet seen info connecting the cluster and light function.

BTW, nothing was recently added, removed, modified, or repaired. Like new radio, etc. Nothing obvious which could have a bearing on the issue. It just happened.

sumdewd

Honestly, I'd start with the easiest stuff first. Check and clean your grounds and battery terminals. I have seen some of the most mysterious behavior occur with dirty or loose grounds. The Del Sol uses an electronic vehicle speed sensor so that may also have something to do with bad grounds since it's also messing up.

After that's done, I would do a current draw test at the battery with the car off and remove each fuse one by one until the draw goes away.

From there, obtain a wiring diagram for that year Del Sol and go to town on that circuit causing the draw. Something's grounding through the light circuit or may be shorted out. I know on some models the sidemarker lights can go through the hazard light switch at some point.

Of course, this is all generic. I don't know if there's some magic fix or known issue for this year Del Sol. I fixed the same issue with a 96 Civic and a 99 Altima by replacing the headlight stalk entirely. Your best bet is to obtain the service manual with the diagrams, though.

Vmates

Thanks for the reply. I've done most of those preliminaries and have the diagrams. Just get current draw through the fuses for rt & lft running lights and cluster/environmental (AC/heat) cluster. So obviously it's as though there is a short somewhere. But you mentioned the speed sensor and as I look at the diagram I see that it could possibly be related. That hadn't occurred to me before. I'll unplug it and see if the lights go out. If so, then cool. If not, then I see a long day of getting dirty trying to trace the issue.

mk378

Look in particular at any wiring that is not stock-- alarm system, aftermarket radio. The running light circuit goes to the radio plug.