tail light turns itself on

giftvolvo · Post by **giftvolvo** » 09 Apr 2013, 12:16

I own a 1998 V70 GLT and lately it's been doing something odd. Sometimes when I have to get up in the middle of the night to answer the call of nature, I'll notice that this car's tail lights are on. No head lights or anything else is on just the tail lights. I have tried turning the switch but nothing happens. If I start the engine and drive around the block and park it, the tail light stays turned off. The problem only repeats itself every few weeks. Any ideas what this might be? I have tried searching for this problem but it seems to be unique.

Post by **abscate** » 09 Apr 2013, 12:22

Drink less in the evening so you dont have to get up ??

Okay - Ill try to be really helpful. Thats a tough one.

Check grounds - bad grounds cause an awful lot of light problems - in this case the bad ground could be in the brake or turn light which is letting power go to ground through the lights.

Make sure which lights are lit - dont assume they are the tail lights because they are on constantly - could be brake or turn lights.

I would start by popping the switch out and seeing if you can isolate where the lights are getting voltage from. It seems for certain it is downstream of the switch- my guess is if you pull the plug on the light switch they go out.

Im sure this thread will get interesting.....

giftvolvo · Post by **giftvolvo** » 09 Apr 2013, 12:57

OK, thanks for the quick response but here's a dumb question. How many grounds are on this vehicle? (it's the standard engine that comes with this model 2.4 L turbo). I'll have to wait to find out which lights come on and see if the switch is the problem since this problem has a mind of it's own when it does this. At first I thought it only happened after it rained and I had set the traction control to 'Wet' but I haven't used that for several weeks now and it did this just the other night.

I will try to drink less in the evening but this problem could drive someone to drink.

Post by **abscate** » 09 Apr 2013, 19:37

There are grounds all over the place on each component...I don't know that model well enough to say where the ground straps are.

giftvolvo · Post by **giftvolvo** » 10 Apr 2013, 07:11

It happened again last night. A cop came to my door to inform me in fact, about 2:45 am. I was mistaken, it is the brake light and not the tail light. Thanks for telling me to be certain about that.

Post by **abscate** » 10 Apr 2013, 07:41

AHA!!

Bad brake light switch on the pedal perhaps. I believe all Volvos of this vintage trigger the brake lights with a switch that is closed when the pedal is depressed, perhaps the pedal is slightly bound up by something stuck in the linkage

giftvolvo · Post by **giftvolvo** » 10 Apr 2013, 13:35

Now that I know it was the brake light, I searched and found this thread: https://www.matthewsvolvosite.com/forums ... =1&t=34816

I will take a look this evening and see if an adjustment fixes it. If not I'll replace it.