Hey Guys,

A couple of weeks ago I started having intermittent issues with starting my 95 850. When I turn the ignition to start, the door locks would engage (which is not a feature of this car) and the car would not turn over. When this happens I have to disconnect and re-connect the ground terminal on the battery and then the car starts. Initially I thought the problem was a faulty door lock module, so pulled the fuse once I re-started the car. However latter that day the car would not start again. Anybody have a suggestion on the next steps to take for resolving this problem?

Thanks in advance,
Bill

 

Are you doing something to mess with your alarm/keyless entry? A lot of wired things trace back to the ignition switch being bad but that is a strange one.

 

Not sure if your locks issue is related or not; may suspect the electrical portion of the ignition switch.

Am assuming this is auto trans?

First step is ck for 12v at the starter green wire (small gauge one) when ignition is in crank position (will need a helper unless you hook up a test wire and/or light).

If you do have 12v there, then looks like starter is bad (assuming you don't have loose/bad high current cables going to the starter).

Since this is an intermittent issue you may want to wire up a test light to the green starter wire and lay it on the windshield under the wiper blade (hope it doesn't rain..) so you can "test" it every time you start it.

If you don't have 12v at the green wire then could be:

1. PNP trans switch
2. Alarm relay (if applicable)
3. ignition switch (elec portion)
4. some other wiring gremlin(s)

 

Hey guys thanks for yours responses.

rspi, I stopped using the keyless entry when this problem started occurring to eliminate this as a possibility. The ignition is a possibility, however it is not directly tied to the door locks as this is not a feature of this model.

gdog, Initially I thought that it may be the PNP trans switch, however moving the shifter around to different positions and back had no effect.

I'm leaning more to a problem with the Anti-Theft relay since the door locks are interrelated. Does anyone know a way to bypass the relay by jumping out the relay block?

Thanks again,
Bill

 

Why don't you just pull the relay and see if that changes anything. I don't even think people try to break into Volvo's anyway.

 

My understanding of the anti-theft relay is that it is required for the car to start. Is it not?

Here's a link to a wiring diagram of the 95 850 anti-theft system: http://www.volvoclub.org.uk/tech/ser...heftSystem.pdf

 

Yes, you are correct. If you want to bypass the relay (the starter disable portion anyway) jumper terminals 1B and 5B; refer to the wiring diagrams, Fig 13 in your pdf; top left corner; grn/red to grn/red wires.

Conversely you could ck for 12v during cranking on pins 1B and 5B. During cranking you should see pwr at both. If neither has pwr it's probably the ignition switch (or wiring); if 5B has pwr but 1B doesn't, then the relay is disabling your starter.