850 wagon '95 Courtesy lights/central locking kaput

volvoheader79295 · Post by **volvoheader79295** » 24 Sep 2009, 09:59

Hello. Great forum and site!!! I just bought a pretty nice black 850 wagon with 180000 miles on it. Runs well and in nice shape, but I think probably wrecked in its last few thousand miles which was not on the CarFax. Anyway, it is a fix-r-upper for very little money out. I have been a 240 guy (I have 4 runners and 1 for parts) and can do some stuff. The 850 is a new animal to me. The main irritation at the moment is the courtesy lights do not work and the central locking does not work either. The lights do work manually, but not automatically when the door is opened. I do not know if it is a switch, a relay (wherever that is and whatever it looks like) or a bad wire or ground. The same is true for the central locking which is a feature of this car. There is no switch on the dash for it, however, at least that I can see. The fuse for it had been pulled and when I plugged it back in the lock on the passenger side will start going up and down by itself over and over. Scared my wife to death! I had to pull over and pull the fuse. I found some used actuators from a junked 850 and can replace if I need to. So my main issues or questions are about the courtesy lighting and the central locking. I need some direction to go in and not start flailing around with needle nose pliers and tape. I have a multimeter and wire testers, but no where to start. Can anyone help me with this?? The Haynes book is not much help in this area, it seems. Thanks!!! ~ vvhdr

FCPEURO · Post by **FCPEURO** » 24 Sep 2009, 10:11

First, look at the obvious things like the fuses and make sure the switch in between the lights is set to auto and not off.

If that all checks out, you will need to look deeper into it. This is when a service manual like the Haynes manual comes in handy.

volvoheader79295 · Post by **volvoheader79295** » 24 Sep 2009, 10:30

Thanks! I will do that. However, I was actually hoping for a bit more specifics from someone who has experienced similar issues with the 850 or similar model. Is there a relay somewhere to test? Haynes does not tell me where exactly. Does this happen frequently? If so, what is the likely culprit? Are the two problems completely separate or are they related somehow since both deal with the door?

Post by **Ozark Lee** » 24 Sep 2009, 12:39

There is a relay, 205 / 206, that covers both the central locking and the delayed interior lighting. That relay is in the lower central electrical unit which is mounted high on the firewall, inside the car, directly below the fuse box location.

If you have not already done so snag a copy of the factory shop manual from here:

https://www.matthewsvolvosite.com/downlo ... vo_850.zip

The schematics are much better than the Haynes.

...Lee

volvoheader79295 · Post by **volvoheader79295** » 24 Sep 2009, 13:56

Thanks very much. I am a 240 guy (I have 4 runners and 1 for parts) and can do some stuff. The 850 is a new animal to me. Very helpful and legible. So I guess that relay is accessible via under the dash and up in there? Just bought a set of TORX screw drivers and sockets for this car. Time to start using them. jg

Post by **Ozark Lee** » 24 Sep 2009, 16:14

So I guess that relay is accessible via under the dash and up in there?

Yep, just remove the lower dash panel (T-25 Torx) and then play contortionist.

...Lee

volvoheader79295 · Post by **volvoheader79295** » 19 Oct 2009, 21:57

Finally back to this project. I found the proper relay and at least the courtesy lights work properly, HOWEVER, the central locking is still erratic and acts on its own, especially when driving. Is it possible that a loose ground wire from the actuator on the right front is causing this? If so, how would I fix that?

Post by **Ozark Lee** » 20 Oct 2009, 07:08

Is it possible that a loose ground wire from the actuator on the right front is causing this? If so, how would I fix that?

Possible but not likely, most of the time it is a bad switch in the door lock. The door switch circuits are completed to ground to activate the circuit. If you suspect a bad ground the ground wires are black and they go to the chassis on the respective A-Pillars.

...Lee

volvoheader79295 · Post by **volvoheader79295** » 20 Oct 2009, 07:49

Thanks Lee. I previously pulled the door locking actuator and replaced it with another one that I discovered had 10 wires at the connector and not 12, which mine had. The replacement did not work electronically at all. So I found a working relay and put my old 12 wire lock back in. The lights work now (probably due to a better relay), but the actuator is very erratic. At least it is doing something. My reason for guessing a ground wire is my experience with 240's and ground wires getting loose. When the car sits quietly the actuator is quiet, but the slightest movement makes it jump. Riding down the road and it goes wild with the vibration. My thinking now is to find another one with 12 wires at a junk yard and hope. My car is a basic wagon and I am speculating that may be the reason for 12 wires instead of 10. Ten wires seems more common. My schematic from the 850 shop manual only shows 10 wires. I love now having the lights come on when the door opens, but alas, I will need to pull the fuse because of the door locks popping up and down and so will lose the lights. Any additional input is welcome. ~ john