My wife's '89 740 GL has lost both its main brake lights. The light over the trunk (back window) still works. Bulbs are good, contacts clean. No voltage at the rear connectors when the brake pedal is pressed & the back glass light is lit.
The owner's manual says that fuse #4 powers the brake lights, & pulling it kills the back glass light.
Other posts talk about 'integrity relays' & repair of same. Could this be my problem, & if so, where are they on the 740? I've followed the bundle from the left tail light assy up to the seat back without finding any connectors.
Thanks,
Charlie