1993 850 Electrical issues

socalvolvo · Post by **socalvolvo** » 07 Oct 2015, 11:36

So I'm having some strange stuff happening. to my 93, 850.
I've written down the symptoms in the order that they have occurred.
One month ago dead battery. Test alternator (good). Buy new battery.
3 weeks ago low battery light turns on intermittently (Start up, and low speed accelerating usually).
1 wk ago: Interior dash lights out (replaced fuse- working now).
5 days ago: Sun roof not working properly. Closed it and have not tested due to rain.
4 days ago: A/C not working properly. Blinking dash light. Low pressure at best.Turned off.
Same day car stalls at idle.
1 day ago: Car is dead. Discover radiator fan is cycling even though not enough juice to crank car. Jump started and ran car for less than 5 minutes. Detached battery so it wouldnt drain overnight.
Today: Car started up. Drove wife to school (A/C off, radio off). Car stalls at idle. Starts back up no problem. Park car, bite nails.

Post by **jose456891** » 07 Oct 2015, 13:36

I say alternator

But that only explains part of you problems.

I would check the wiring harness for exposed wires/rodent damage

Car stalling could be from a sharp electrical load (ie short), bad ignition rotor, fuel pump, MAF.

Go to this thread and pull the codes off the ECU. That should help us help you better.
https://www.matthewsvolvosite.com/read-codes-volvo-850

Carboncopy · Post by **Carboncopy** » 07 Oct 2015, 14:10

Check for a short or loose connection at the starter terminal where the B+ wire from the alternator meets the starter solenoid. I was having an intermittent stalling and dead battery problem myself and that's what it turned out to be. Took me a while to track that down after driving myself nuts testing the alternator and batteries.

socalvolvo · Post by **socalvolvo** » 09 Oct 2015, 18:12

Update so far. I've been working so haven't had much time to work on this problem however i had the alternator checked again and it's good. The dash light fuse burned out again.
I just tried to pull some codes and A-jumper is not working at all. No blinking in any of the slots.

850TurboTurtle · Post by **850TurboTurtle** » 09 Oct 2015, 22:54

My 95 850 has about 7 smaller red wires coming off the positive battery terminal as well as the main lead. Given the race of problems, you might check that connector and make sure everything is tight.

socalvolvo · Post by **socalvolvo** » 01 Nov 2015, 15:11

So i was about to give up and bring the car to my backyard mechanic because it started to stall in dangerous idle (stops signs,Red lights). However some drunk A**hole sideswiped the car while it was parked on my block. Hit and Run. Broke the axle, bent tie rods, warped knuckle. So it went to the mechanic anyway. Replaced everything but the mechanic couldnt replicate the stalling, or the stuck radiator fan. He removed the sunroof circuit thinking that the short could be causing the problems. I got the car back and drove all over town, No issues. The next day stall at idle. Stall at idle. And then Stall while driving to mechanics. Basically coasted into his lot. Would not start after that. So it's back at his shop. Hoping for the best.

sjbock1 · Post by **sjbock1** » 05 Nov 2015, 19:24

Have you checked the camshaft position sensor and the wiring for it? I have an 94 850 NA that tries to stall at stop signs and red lights in humid or wet weather until I've been driving for about 15 minutes and I guess the wiring dries out. To prevent the car stalling in wet weather, I put the car in neutral and turn off the a/c when idling. I noticed a few months ago that the plastic cover on the electrical connector from the camshaft position sensor looked cracked and as if the lower 1/4 of it was missing. Sure enough when I stuck my fingers in there and touched the electrical connector, the whole plastic cover disintegrated leaving the wiring exposed to the weather. I couldn't disconnect the electrical connector because of 22 years of grease and dirt. I didn't want to force it because the car still gets me to work and I haven't had time to get a new camshaft position sensor. (Actually I'm not sure which sensor to buy because the Bosch number on my sensor isn't exactly the same as the ones I find for sale on line. I also noticed the part number on my original MAF is different from the ones I see for sale.)

socalvolvo · Post by **socalvolvo** » 05 Nov 2015, 19:45

Thanks for the reply. It could be The CPS but that doesn't account for all the other funky elec issues (sticking fan, sunroof and dashboard short etc). A few years ago I was having stall issues and replaced the CPS. The stalling was solved. However, i bought a used one ($40us) at a volvo wrecking yard. A new one is approx $250. I believe they are pretty much plug & play. It was an easy fix. It very well could have also failed. I wish it was that simple this time but i fear it's more complicated.