I'm a newbie, which may become even more apparent as you read my questions. I owned a 1995 base model 940 wagon for almost 10 years and it now has ~166K miles.

Today yhe bulb failure warning light on the dash lit up when I started the car and, being all-too-familiar with the frequent bulb failures on the 940, I immediately set about figuring out which bulb was out.

Everything up front seemed OK, but when I checked the rear lights, the top light (fog light bulb?) was burning brightly only on the left side tail light (US driver side). AH-HA, I thought, easy enough...but I was wrong. I popped off the covers to the tail light housing inside the rear of the wagon and immediately saw that there WASN'T A PLACE FOR A FOG LIGHT BULB in the top position on the right side, which may explain why there was no top light burning there. How had I owned this car for so many years and not noticed that??? My car doesn't have front fog lights and I never think to use the rear fogs, so I never throw that switch, except possibly by mistake. But my first question is...is there really only one rear fog light on one side of the 1995 wagon or should the other side have one too?? Mine doesn't even have an opening in the housing for a bulb. And if I'm only supposed to have one fog light, how come the warning light comes on even though the fog light works?

But now I have a new problem, which is where it gets even more confusing for me...

I checked all the tail light connections, disconnecting and reconnecting the wires and bulbs in both tail lights, along with checking the tail light fuse, which was fine. Apparently the bulb failure warning light ONLY lights up when the fog light switch is turned on, but the only fog light bulb is working fine.

Here's where it gets even more confusing for me...I now have no brake lights yet the bulb failure light on the dash doesn't light up unless the fog light switch is turned on. No brake lights and no bulb failure warning related to the brake lights. Any ideas?

Based on other online posts, it may be the bulb failure relay, but before I buy a new one for $60-80, I thought I'd check with you folks to see if there's something else to check.

Frustrating....

That left side light is a parking light. They're only on the left side for parallel parking. Other than that, I can't help you.