View Full Version : Mystery button and indicator lights

12-13-2007, 05:01 PM
I just picked up my 1997 D90 the other day. I've been driving it sparingly during this salty-road weather we're having in Mass. Anyways, I've been trying to figure out what a few mystery buttons do, and some indicator lights.

Here's a picture of the indicator lights. The middle light stays on all the time, even with the truck off. I've tried pressing all sorts of light switch combinations and nothing gets any of the other 2 lights to turn on. I have no idea what these are for! I do have an alarm with keyless entry. The alarm light is on the other side of the dash, and blinks when the alarm is active so I'm thinking these aren't alarm related.


In a similar location, I have this black push button under the dash. Again, no idea what it does and it doesn't do anything when I press it.


I also have what look like 2 toggles (3 position each) for city lights? These don't do anything either when I toggle them (with or without the parking/main lights on or off).

Any ideas? Love the truck. The white stuff in the pictures is snow blowing in :-)

Tyler from Mass.

12-13-2007, 08:49 PM
On my 90 that button near the dash is the passenger seat ejection button! Just kidding. Those light switches though are simply placed in the auxillary switch area and could have easily been wired to some kind of fog lights or work lights. :D :D :D

12-13-2007, 09:05 PM
Is it typical for buttons like these to have been wired then disconnected? I have Hella lights up front, and a work light out back. Those are controlled by, yet another, set of switches in the center of the dash.

The indicator lights are the most intriguing though since they are still "active". Active doing what is the question!

Once I've had the truck for more than a week :D I'll think about taking apart the console and traceing those wires. Would help if the thing fit in my garage... turns out I need to work on it in the driveway.

UPDATE: I'm pretty sure the black push button is the Viper/Python security system's valet button. The others are still a mystery.

12-15-2007, 04:06 PM
Why not ask the guy you bought it from?

12-15-2007, 07:40 PM
I'm not sure who the previous owner is.

I figured out that one of the toggles has no wiring, the toggle for the dash dimming was disconnected (reconnected it) and the other toggle has something to do with the Hella lights. Not sure yet, but it runs to some relays.

The 3 LEDs ran through the dash and firewall, then back under and up through the battery compartment to a small battery charger! The LEDs indicate battery charging status. This also explains the outlet hanging out the front of the vehicle, which is the power hookup for the battery charger.

Was a fun little investigation, and got me to learn how to remove the dash.

12-15-2007, 10:35 PM
Good for you for diving right into your wiring!:thumb-up: