Hi there. Rookie Volvo owner here. I'll post a full intro soon, but first I have an interesting question.
We just bought this wagon,174k mi,75k on rebuilt engine, and everything works fine except that the driver's side headlamps (hi and low beam) are DIM! When I switch from hi to low and back again,the engine wants to stall out; if I'm signaling for a left turn or have the 4-way flashers on, it WILL stall out. UNLESS the front left turn signal lamp is unplugged at the socket. Then it's fine and I can see into the next time zone. Also, the upper side brake lights don't work(bulbs are ok) and the fog lamps are inop. I suspect that the combination switch is shorting out internally,but any other possibilities are open for investigation. This car has been in New Mexico for a few years at least, so I think that corrosion is not a major concern. Still, I've been wrong before....All ideas are welcome!

As for the taillights... there are no upper brake lights, unless you mean the one in the hatch. Only the bottom sections of the lights are lit.
The upper red part is only for rear fog lights, and it's only on when the headlights are on, and only on the left side normally (so you can tell that they AREN'T brake lights).
--
Rob Bareiss, New London CT ::: '86 244DL- 215K, 87 244DL- 230K, 88 744GLE- 198K, 91 244 180K

If you look under the hood at the L/H front inner fender below and behind the headlamp there are several ground wires connected to the body at a common point.
These ground all the lights on that corner of the car and, I suspect, the ignition Power Stage ( or ignition amplifier as it is sometimes known) which is fitted behind the air filter box.
If the lights are dim due to this ground being bad it could bring the ground connection for the Power Stage well above 0 Volts and effectively reduce the supply voltage across it to less than that required for it to operate.
I`d bet that cleaning up the grounds will cure this problem.
Maybe one of the resident gurus here can come up with a better idea, but this seems to me to be the most likely answer. Don`t forget to post when you do find the answer to the problem.
Good luck,
Colin,

Colin-
You nailed it dead-on! I unbolted the ground terminals from the body(10mm hex),cleaned them and the bolt on the wire wheel, replaced one female terminal, cleaned up the other one(actually the fog lamp ground for that side),scuffed the body around the bolt-hole a bit, put it all back together and WOW- good as new! Side marker light works, all signals work, high-low beams work. No front or rear fog lamps yet, but I suspect that cleaning the other side, which is BURIED behind the air-filter box, may help with that. Fog lamp bulbs and fuses are okay, but no voltage is getting anywhere. It looks like I'll need some time to uncover that other ground terminal block-definitely not today :-0
Thanks,fellas!
-shirleysdad

Glad to be able to help, and thanks for posting the results, this is the only way we know if our advice is correct.
It`s not only gratifing for the person who posts the correct advice but widens the knowledge of all of us here.
Best of luck with the rest of the problems.
Colin.

Wow! I LOVE that diagnosis. It sure does make sense, and it's one of those damn things that would have you scratching your head for days!
I was thinking more along the lines of a short circuit, which didn't make sense- it should have blown the turn signal fuse. I like it! Clean up the ground screws and see whatcha get!
--
Rob Bareiss, New London CT ::: '86 244DL- 215K, 87 244DL- 230K, 88 744GLE- 198K, 91 244 180K

Check ground connections at left of head lights. Check the FAQ for more info.

welcome and good luck. Joe

I see the terminal block-just above the battery; headlight and side light grounds running to it. I notice some light corrosion on the headlight plugs themselves, where they plug into the bulb. BTW, just how many grounds should be plugged into this terminal block?(:/ I only count two....I almost wish this wagon didn't have an airbag; then I could get to the combination switch in less than a day and troubleshoot this from both ends....more later as I find it....SD out.