I have done the following: 1989 Volvo 740 wagon
Replaced every bulb in the car...all the same brand
Cleaned and checked all contact points for bulb sockets
Used dielectric compound on all connections
Replaced the bulb out relay

I have chased the problem from the back to the front of the car and back again. For a while, I could change the bulbs around and get my front signals back but now it seems stuck at this failure.

I now get the dash light only when I hit the brakes, and no front turn signals. Rear signals blink fast. Every light on the car works fine, even the front running lights that share the duty as the turnsignal.

I know I have an open somewhere, can anyone point me to the next step from a similar experience? Maybe a specific or common area of the wiring to check?

It is making me crazy!

I have read the FAQ's and know that I am close.

Thanks,
Edmund

are you sure you used the proper lights in all the sockets? single and dual filament bulbs? have you checked the grounds at all 4 corners? do you have the correct rear light assemblies? sometimes if you have replaced rear assemblies the electrical connector will work, but they are wired with the brake light on the upper inner instead of the outer lower.

Yes, all bulbs are as they should be. Light assemblies as far as I know are stock. I am going to check the grounds as you mentioned.

Thanks!
Ed

The only front lights checked by the Bulb Failure Sensor are the Low beams. So if you have a front signal lights problem, it's a separate issue.

At the rear, only the tail and stop lights are tested by the BFS.

Socket and ground conditions are suspect, if all bulbs light.

I believe there is also a wiring connector between the bulbs and the sensor, where poor conductivity might upset the Left/Right current balance.


--
Bruce Young
'93 940-NA (current) — 240s (one V8) — 140s — 122s — since '63.

Does anyone have an idea on where the connecter should be between the bulb out sensor and the lights?

Thanks,
Ed

I went through everything today, again.

I changed out the bulb holders, and ensured a good clean connection to all of the contact points on the tailight assembly. For about one minute, I got the left signal working on both sides. I went into the house, tried it again, and I got the fast blink in the rear and no fronts again...all the while, I get the signal out bulb when I hit the brake pedal.

My Wife came out to assist with checking what lights were working in back and reported that everything worked expect for the top tailights. All brake, including the high mount are working. Reverse lights work, signals on fast blink, still no fronts.

Up front, i found the small light under the headlights full of water and the bulb holder a bit rusty. Those lights have never worked (I have had various lighting issues since I got the car...went away and was fine for a month but is now back with a vengence). Could these be causing the problem? I grounded the negative cables but that did not do anything. The running light portion of the front signals are lit when the headlights are on. There is a two element bulb in those.

I traced the grounds and they are all tight and appear in good condition.

Anyone have more things to check?

Many thanks,
Edmund