Okay I am about to buy a 1993 850 GLT with 78,000 miles but when you turn the head lights on the AC comes on and vice versa. Also it is not blowing cold air.

Any helpful hints? Also should I buy the car or is it a indication of problems to come? Thanks for any advice.

Usually that's a ground problem somewhere, causing current backfeed into an adjacent system.

It can take literally days to figure that out. It isn't necessarily a sign of a totally messed up electrical system, but it's an indication that something has gone amiss and should be corrected, and the cause identified.
--
Chris Herbst
1992 945, 71k
Volvo shop tech

electrical probelem is the most expensive and costly to fine out....


try to get something newer ... 1994 or later,,, first year is the lemon. all dealer and shop said to stay away... ......

Just do it... another one will come your way... don't buy 1993 just don't do it...

I'd skip this car. Electrical / electronic problems like this have the potential (bad pun) to drive me crazy troubleshooting them and that's what I do for a living. It's possible that it would be an easy fix but I wouldn't bank on it. The car could have been flooded but it appears obvious that the wiring harness has a short between the two affected circuits. It's FINDING it, and realize it is never in an accessible place, like in the dash, that makes it difficult.

As far as the A/C, search this board and you'll find LOTS of information about 850 evaporators going bad and leaking refrigerant. A very expensive repair at over $1000.

Personally, I never buy first year models and '93 was the first year 850 in the states. Look around and you'll find a really nice '94 or '95 and keep in mind, when looking for an 850, a verifiable maintenance history is the holy grail.
--
Erwin in Memphis, '95855t, '86 Guzzi LeMans, '76 Montesa 348 Cota

Eric,
Run don't walk from this car...then go check out a later model year.

I would avoid a car with an electrical system that is as messed
up as this. Go look for another Volvo. There are plenty of them. :)

kevin