2001 Oldsmobile Alero Service Vehicle Soon.
Question: Why does my left and right brake lights don't work but the middle brake light does?
There doesn't appear to be any blown bulbs or fuses.
The high mount stop lamp is on a different circuit than the left and right brake lamp as it come out of
the left fuse dash fuse/junction block. It is possible that you have a bad connection within or on the
back side of that block for the wires that run to the brake lamps.
Since you did not leave the model year, i went with a 2001 Alero. These blocks have a tendency to
get corroded by water intrusion. It may show signs of water intrusion by removing several fuses and
look for signs of dried up water/rust, also on the back side of the block where all the wires come out.
This condition is probably the reason for the service vehicle light on the dash. But cant be sure
unless have the BCM (Body Control Module scanned for codes.
2001 Chevy Venture van.
Driver side turn signal works fine when the brake is NOT applied. As soon as brake is applied, turn
signal flashes very fast. Also related, when cruise control is on and as soon as you turn on the driver
side turn signal it turns the cruise control off.
Also related, when in reverse, the driver side turn signal does not work at all. Tried replacing the
bulbs and didn't work. Autozone suggested replacing the Brake light Switch.
As long as the bulbs that were replaced were the proper type, then this sounds like a problem in the
driver side rear lamp circuit board assembly. Sometimes the connector gets corroded, or the board
shorts out internally, causing all kinds of odd lighting problems, shorting out, open circuits, back
feeding. Try swapping the entire assembly with the pass. side, and see if the problems follow. If they
do, then you have a problem in that board.
Are You A Mechanic?
Your Help Is Needed In Our FORUMS
Brake Light And Turn Signal Problems