Ok this is a weird one.

My turn signals worked fine with the headlights OFF but once the parking lights or head lights were turned on I would have the rt turn signal illuminated (no flashing) and the left side did not work at all.

I assumed I needed a new flasher / relay so I picked up a good used one. FYI- Its integral to the hazard switch on our cars so its not cheap...

Fifty bucks later I have the same problem however the left blinker works with the headlights on but the right side stays stuck on. I started fooling with fuzes and relays under the hood and found that the problem went away when I pulled the relay for the parking light nothing surprising here, but since many of the relays are common I tried switching a few of them around to no avail.

I decided to spent the day chasing grounds starting in the rear and all looked good. when I went to the front and pulled the right (passenger side) turn signal bulb I found that the connections on the dual filament bulb had serious signs of creep and were contacting each other! I cleaned up the bottom of the bulb with a file and made a new grove into the plastic between the two electrical contacts to restore isolation and voila its fixed!

Hopefully this saves someone else a little hassle and money....

Thanks for reading,

Will

Good find! A search of the archives might have turned up this thread noting my similar situation. I just replaced the $2 bulb, thinking the heat may have used up too much of its allotted lifetime.

http://www.brickboard.com/RWD/volvo/1410422/S90-V90/turn_signal_poltergeist_exorcised.html
--
Bob: son's 81-GL, dtr's '94-940, my 83-DL, 89-745(V8) and 98-S90. Also 77-MGB and some old motorcycles.

Just so you know you can trim the solder between the two contacts, using a knife, so that they are no longer touching and you don't even have to replace the bulb.

Once the excess solder is gone the problem won't re-occur. When you put in new bulbs the problem will come back eventually.
--
~William~ 1985 240 DL - 365,000 & 1998 V90 - 190,000

Mystery solved!

This was a great recommendation. replaced all four bulbs. But just so you guys know, Autozone has the wrong bulbs on file for the rear signals. I had to match them manually...

Anyway, Right turn signal dual souldered points were fused together.

Thanks for posting the solution. As often occurs, it's corrosion and age at electric connections that bedevil these older cars. This exemplifies the virtue of looking at simple trouble spots first.

Chris in VT, '94 945 w/ 168K

Wow, this is the same problem I am having with my 98 S90 (218K Original motor). I read in another forum that they guy replaced all four of the turn signal lights, and fixed it.

I have replaced the hazard/turnsignal relay/switch.
I pulled and tested the turn signal switch and it tested out ok.
I pulled the turn signalfuses, and the right turn signal still persisted.
Then I noticed that when I turned on the headlight switch when off into "Parking" mode, the right turn signal would come on solid.

I was beginning to be worried that I had a murned out breadboard under the relays, or wiring that went bad.

Thanks for posting. I will check this out today!!! We'll let you all know!