1997 850 NA Automatic not starting

[BlackThunder]

As always, Thank you for all the help here on MVS. I bought an Innova 3320 Multimeter that has automatic settings for DC and a large display - it is really nice so far.

I will check the immobilizer relay as soon as I can. I'm hoping it is something easy like that. In Minnesota there is already snow on the ground - so I have to get this done soon since I have to work outside.

Dustin

[BlackThunder]

Finally got a chance to work on my car again. I pulled the relay - it was way up there. Mine is under the dash. Hoping to see if I can either get a new relay to try or somehow bypass the relay. Maybe I could test the relay itself to see if it is good?

Relay

Dustin

[BlackThunder]

Update, pulled relay doesn't seem to matter. I can't get it to start but by hooking up a wire from the positive battery terminal to the green wire on the starter the car will start.

Any ideas?

[youtube][/youtube]

[erikv11]

With the red wire hooked up like that, you are doing what turning the key is supposed to do - providing 12 V to where the green wire connects. Since your wire works but the key doesn't, then as dj_v70 said, something is wrong in the regular electrical path from the battery to the where the green wire connects.

According to dj_v70 (sorry, I didn't dig up the wiring diagrams and read them myself), the normal electrical path is:
(1) red post on battery, then through that little red wire on top to and on to the ...
(2) ignition switch
(3) alarm relay
(4) PNP
(5) where the green wire connects

So you see, actually, just pulling the relay was not the suggestion. Look at the path 1-2-3-4-5 above: when the alarm relay is out, the key will never start the car, because you have broken the electrical path at position 3.

The suggestion was to pull the relay, put the red voltmeter cable into pin 50, put the black to ground, then turn the key and see if the voltmeter reads 12 volts. You may want to read the post by dj_v70 about this again. If it reads 12 V, then the path is good up to position 3 and you will want to do a similar test for position 4, after the PNP.

Alternatively, you can test the alarm relay by reaching up where it goes and jumpering it, but I don't know which socket hole you need to jumper to the hole for pin 50; likely someone else does.

It is sounding like a PNP problem but to figure it out you need to test each segment.

[dj_v70]

Erikv11, thanks for clarifying my post. You definitely explained it better than I did!

Dustin, we can tell you how to bypass the relay. However, the most expedient way to troubleshoot a problem is to cut the potential issues in half. The procedure that Erikv11 and I outline essentially does just that Please attempt Erik’s procedure. This will prove whether signal is making it through ignition switch and to input of relay. If you see 12v there, we can try bypassing relay next. If you don’t see 12v, there is no sense bypassing relay since problem would be before that. Let us know your results.

[BlackThunder]

Ok, thank you for the clarification. I replaced the ignition switch last year and that seemed to help back then. The car would only sometimes not start but after a while and a few tries it would eventually start. I'll test the socket and report back.

I did test the green wire and I was getting a reading - I can't remember the exact number but it was close to 12 v.

Also any tips at how to put the relay back into its socket when all this is done would be helpful. I spent a long time just trying to put it back and I cannot seem to get it to slide into the socket.

I'll go through the order and report back. Thanks.

Dustin

[BlackThunder]

I tested the 50E pin with the red lead and hooked up the black lead to a jumper cables going back to the ground on the battery. Readings went from 14 to 0 see video:

[youtube][/youtube]

Also I think I need to test for continuity again with the red wire. I did it before but I may not have done it correctly. I did put the black lead on the thin red wire and tested all of the contact spots on the starter where the red wire connects:

Testing contact points

Which red wire do I test for continuity? Also that means putting the red lead at one end and the black lead at the other. What should my multimeter be set at?

Top view

I appreciate all of your patience and guidance!

Dustin

[BlackThunder]

(2) ignition switch

When you say ignition switch you mean the ignition switch where the key goes in, right? That had some play in it and I had figured that was giving me random problems last year so I replaced that. BUT if "ignition switch" means something else then maybe I have overlooked something?

This is what I replaced last year:
https://www.fcpeuro.com/products/volvo- ... 60-9447803

[dj_v70]

I tested the 50E pin with the red lead and hooked up the black lead to a jumper cables going back to the ground on the battery. Readings went from 14 to 0 see video:

I looked at video. Your voltages are 143mV (note mV symbol in top right corner of screen) and 0. 143mV=.143V

I expected you to get 12.6V when key was turned all the way to start the car and 0V when not turning key. Either I told you the wrong pin to look at, or your problem is before this point and we should be testing at ignition switch next. It has been a few weeks since I looked at wiring diagram, I'll look at diagrams again and get back to you later today for recommendation.

Also I think I need to test for continuity again with the red wire. I did it before but I may not have done it correctly. I did put the black lead on the thin red wire and tested all of the contact spots on the starter where the red wire connects:

Which red wire do I test for continuity? Also that means putting the red lead at one end and the black lead at the other. What should my multimeter be set at?

You have two wires on your starter. A big one and a little one. Based on your testing, the big one is fine. The problem is with the little green wire. Again, the signal path for small batter wire is: battery(smaller red wire)-> ignition switch -> relay -> PNP -> starter (little green wire). Something is broken in this path. When you put key in ignition and turn all of the way clockwise (which normally starts the car), 12V is sent from battery through ignition switch to relay. If relay and relay control circuit (alarm) is functional, 12V is passed through relay to PNP. If PNP is in park or neutral and functional, it passes 12V to your little green wire at starter. When starter sees this 12V, it engages internal circuit to grab 12V from big starter wire and turns the starter motor.

Any wires in this circuit can be tested with multimeter. Just need to put your meter in “ohms” mode and touch meter probes to each side of wire to be tested simultaneously. Meter should read close to 0 ohms if wire is good. However, you don't want to test wires with voltages on them, that can give you unpredictable results. So, I wouldn't recommend trying to test for continuity from the battery to the starter by using ohm mode. You are effectively testing the same thing anyhow by checking to see if the voltage is there. Usually, it is easier to just follow the voltages through system first before looking at wires. For example, if we correctly have 0V at relay input and 12V at ignition switch output, then you would want to check continuity between ignition switch wire and relay while key was NOT turned so that there was no voltage there. So, let's hold off on continuity testing with ohms mode.

I did test the green wire and I was getting a reading - I can't remember the exact number but it was close to 12 v.

If you had 12V at green wire, your car ‘usually’ should have started. That is how you are starting the car by jumping from the battery to the terminal on the starter that the green wire connects to. If you reconnect the relay, you can re-test this. Disconnect green wire from starter and put voltmeter on green wire (should be 0V) and then turn key all of the way to start the car. While key is turned do you read 12V? If so, connect the green wire to the starter and re-test the voltages again with meter while turning key. If you still have 12V, the starter will crank. If you have 12V while green wire is disconnected but 10V or less while green wire is connected, that would be a clue. It would mean that one of the parts or wires in this signal path is degraded but not fully faulted. The problem is that this does not concur with your relay measurements.

Do you have access to google hangouts? If so, I will PM you with my username and I can walk you through the troubleshooting process while you work on the car. This would be faster for both of us, I am a slow typer

[abscate]

OK - back to basics

"car won't start"

Turn key to starting position

Does it.......

No lights camera action
Lights come on dash, no cranking ?
Cranks, does not fire
Cranks, sputters