7

On a 2003 Saab 9-5 Aero, only the left rear fog light lights up. The right side has a bulb but when I switch the bulbs, the left still is the only side that lights up.

I thought it might be a wiring issue, however a friend mentioned that his Porsche only has wiring and bulbs on the left side for the reverse fog light.

Is the left side really the only side that should light up for a pair of rear fog lights?

(The fact that the right side has a bulb in the Saab seems strange to me, but maybe it was easier to make them symmetric during manufacturing).

jzd
  • 3,615
  • 24
  • 35

4 Answers4

5

I did some research on some Saab forums. I found that typically on US bound Saab 9-5 a bulb is installed on both sides. However, the metal circuit on the passenger side is cut to disable that side. This is to prevent the rear fog lights from appearing as brake lights (there are arguments about the legality of dual rear fog lights in certain US locations).

It appears the circuit can be soldered back together and to enable dual rear fog lights.

jzd
  • 3,615
  • 24
  • 35
1

The legal requirement (in the UK) is for there to be at least one, however where your car is fitted with two rear fog lights they should both light up, otherwise you could fail an inspection if the police decided to stop you.

All the cars I have ever owned have had 2 rear fog lights, but you do see a lot which have one side fitted with a red fog light and the other with a white reversing light.

I would advise checking the wiring.

Rory Alsop
  • 18,600
  • 7
  • 60
  • 100
1

I have a 1993 Saab Saloon and only have one fog light on the drivers side. It must be designed like that.

DucatiKiller
  • 32,976
  • 22
  • 150
  • 267
Stevie.
  • 31
  • 1
1

VW (in the Bentley service manual) says that only one of the rear fog lights is used (depending, I would think on the side of the road where the car is driven).

The rationale that I've seen for this is that the rear fog needs to be distinct from a brake light, otherwise it may just cause confusion. Since rear fogs are rare in the US, they probably just cause confusion anyway, but hopefully a bit less.

dlu
  • 14,506
  • 8
  • 52
  • 85