92 volvo 740 wagon, 4 cyl auto regina. Brake lights stopped working a while ago. Checked the fuse #4 --good. Shift interlock works. I replaced the brake light switch even though I think it was fine. Took the bulbs out and tested, they all work. The haynes manual shows no relays, but Judging by the thinness of the two wires going to one connector and the three wires to the other connection of the brake light switch, I cannot believe that current for the brake lights is flowing through that switch. Can Any good soul please guide me as to where I might look for an answer. If nothing surfaces I may jury rig an old fashioned non relay style of brake light system but If I can fix it properly all the better

Thanks all Volvo gurus

Brian

 

This is a weird one that bugged me for a while.
Turned out to be the bulb failure sensor in my case.
Also knowing the difference between the brake light switch and the switch that cancels the cruise is handy... this bugged me on a 240.
Ed7

 

Well, ok Brian, but only if you promise to cut down on the posting! Two posts in two years...getting a little ahead of yourself, mister!! Just kidding...If you have digital multi0meter you might check if power is making it to the brake lights. If it is, than you probably have a bad ground and it's probably in the trunk where it got hit by cargo. And yes, the bulb out relay will cause these symptoms. They're cheap at fcpgroton.com