740 Gle sedan 1986 inside, stop/ brake/ fog, red light

[jonaix]

I am currently experiencing no rear "fog" stop lights, at least thats what I think they are called. The most inner two stop lights on my sedan... I have been struggling with my brake light failure warning lamp in the instrument panel cluster, for some time. I believe the bulb failure relay's are fine since I get the same result of no brake light in the fog lens, with three different relays. I am currently looking at my fuse/relay holder from the underside and inspecting all connections and wires, etc., and I was also wondering if there is a resource somewhere on-line where I can find the way it should look... I understand it is very precise information to request. But, I believe this is what the original post is requesting. For example... I have several wires that are clipped/piggy backed, and overall really clustered up and tangled in knots behind my ashtray, how can I become to make sense of these wires? and would anyone understand where the fog brake light wire sits in the cluster? Thanks

[jonaix]

The lights aren't coming on when the brake is pressed down. The double filament bulb is, but the inside, stop/ brake/ fog, red light on my sedan, is not functioning. The diagnostics performed have been:
-I have checked what I believe to be most of the relevant fuses.
-no bulbs are out.
-replaced the Bulb Failure Warning relay 3 times with 3 different relays (possible that all three are no good, though I think differently).
-And I've jumped the positive wire from the double filament bulb on just one side of the car--then both lights came on, on both sides SO, I think the ground is working fine for the lights.
-I've inspected under the relay/fuse holder, and found that indeed there was nothing wired into the number three position which holds in parentheses this "(rear fog lights)"; then I found that at position 25, it reads "(rear fog lights USA/CDN)", I then realized it's fuse was missing. so I put a 15 amp fuse in there. And then the warning lamp on my instrument cluster stopped lighting up, which is a blessing.
--But, as far as I know the rear fog lights are still not lighting up when the brake is pressed.
Any advice from here on out is greatly appreciated. Thanks

[billofdurham]

Welcome to Matthew's Volvo Site.

I have merged your posts as we don't encourage posting similar topics in more than one thread. However, there is some difference in detail in the two posts so they are both available for other members to read.

First I need to clarify which light isn't working. I believe it is the rear fog light but you refer to the rear "fog" stop lights. The rear fog light(s) aren't stop lights. They only illuminate when you switch them on using the switch on the dash. The switch is located to the left of the steering wheel next to the main light switch. The headlights must also be switched on.

The purpose of the rear fog lights is:

Rear fog lights
The rear fog lights are considerably brighter than the normal tail lights and should be use only when atmospheric conditions, such as fog, rain, snow, smoke or dust reduce the daytime or nighttime visibility of other vehicles to less than 500 ft. (152 meters). (The headlights must be switched on.)
Note that local regulations governing the use of these lights may vary.

The above information is from the owner's manual. If this doesn't answer your query post back.

Bill.

[jonaix]

Thanks for clarifying as to the rear fog lights. I am actually wondering about the most inner red light on the back of my sedan. Is this a stop light? or are they the fog lights? are they supposed to turn on when the brake pedal is pressed? if so, I'm in a difficult position because I don't see why they aren't turning on.

[billofdurham]

Outer top - turn signal.
Outer bottom - tail light/brake light.
Centre top - reversing light.
Centre bottom - tail light.
Inner top - reflector.
Inner bottom - rear fog light.

The rear fog light does not turn on when the brake pedal is depressed only when you switch it on with the headlights as in my previous post.

If you don't have an owner's manual you can find one at: Owner's manual

Bill.