1998 V70 AWD intermittent no crank condition

Post by **holler1** » 15 Jul 2008, 19:08

Car intermittently doesn't crank. I checked starter and solenoid. The problem seems to be that the small lead to the solenoid (blade connection) doesn't always get voltage when the ignition key is turned to start. There is 12 volts at the large solenoid connection, and when the car doesn't crank there is no voltage at the solenoid-to-starter connector. I could not get a positive voltage reading at the blade connector, but the car starts reliably when I connect the battery + post directly to the solenoid side of the blade connector. So the starter and solenoid seem OK- So far so good. I found a circuit diagram for an 850 which shows a green-red wire coming from the ignition switch to the ECU and then through the auto trans switch (PNP?) finally to the green wire to the starter solenoid. I put a stickpin through the green-red wire from the ignition, and it reads about 5.8 volts to ground (ground connected to the steering column) when I turn the ignition to position 2. The voltage goes down a little when I turn the ignition to start, the car fires up, and the voltage goes up a little (alternator comes on). So far I haven't gotten a voltage reading at this wire when it fails to start. The voltage reading out of the ignition switch seems peculiar, and I'm wondering if the ignition switch is bad. However, all the dash lights come on OK and are the same no matter if the car cranks or not. Moving the gearshift back and forth a few times seems to have no effect.

I guess my question is - based on experience, what part of the system is mostly likely to cause this? The ignition sw looks easy to replace, but how likely is it to be the problem as opposed to PNP or something in the central control unit? Thanks for any suggestions. Info on this forum has been great! I found several similar problems but not identical.

les & reilly · Post by **les & reilly** » 15 Jul 2008, 19:15

very common fault is the ignition key switch. i was reading somewhere on here that you dont need to change the lock for the repair.

try wiggling it about, twisting etc to see if it is definately the ignition switch on the keylock

good luck and get back with your findings

Post by **holler1** » 15 Jul 2008, 19:25

Thanks. The switch looks like the cheapest fix so I hope that is the problem. I'll try wiggling the switch and wires before ordering a new one. Actually, after I "pinned" the wire, the car started several times in a row so I guess it's possible it was a loose connection. I'll try again tomorrow.

Post by **holler1** » 17 Jul 2008, 18:58

Update- Car has started about 10 or 15 times in a row, so I think wiggling the wires around the ignition switch fixed the problem at least for now. I still don't understand the 1/2 battery voltage out of the ignition switch, but I'm not going to kick a gift horse in the mouth (so to speak). Thanks to les & reilly for good advice.

les & reilly · Post by **les & reilly** » 17 Jul 2008, 19:53

ji pleased to hear some of my knowledge has been usefull.
so far, on my s80 t6 i havent had any luck, after spending day after day to fix it, found one fault, thought id solved it, but still no change in the gears.
i will not give up though, i have the time to look, but not the

Post by **holler1** » 04 Oct 2008, 09:27

My "no crank" problem is back, except it is now all the time, not intermittent. Seems to have come back with cooler weather now in the 40s at night. I just replaced the ignition switch (electrical part) and that didn't fix the problem. I can take a wire from the "50" terminal on the ignition switch and connect it to the blade terminal on the starter solenoid, and the car starts when the key is turned. So the ignition switch is not the problem. I suppose the next suspect is the PNP switch, but there are no other symptoms indicating a PNP switch problem. I'll try some more diagnostics today between football and playoff games on TV.

Any ideas on how to diagnose possible PNP or other problems are welcome!

Post by **holler1** » 04 Oct 2008, 10:21

Never mind. It appears the problem was a slightly corroded connector on the wire to the blade connector on the solenoid. I tightened up the connector and the car is starting. I won't consider it fixed until it starts on a cold morning, but it looks good so far. I now have an extra slightly used ignition switch that I think is OK.

Post by **Ozark Lee** » 04 Oct 2008, 12:45

You mentioned some PNP symptoms - that will also disable the starter if it gets bad enough. It normally exhibits a bunch of other bad things before it gets that bad though.

...Lee

Post by **holler1** » 04 Oct 2008, 20:31

Yes, I was worried it might be the PNP since (I think) the wire to the starter solenoid goes through it, but luckily I found the connector problem before tearing into the PNP. There are no other PNP symptoms. I should have found the connector problem before replacing the ignition switch. Sometimes I overlook the obvious.

I had starting problems back in June/July but they went away after I fiddled with the ignition switch wires, so when they came back I assumed it was the ignition sw.

Post by **holler1** » 06 Oct 2008, 18:45

With the cold weather the last few days my "intermittent no crank" is back. Apparently my scraping the connector to the solenoid relay coincided with the car deciding on its own to start again. Today it wouldn't start at all and when I got home tonight I scraped a bare spot on the green wire to the solenoid and connected a voltmeter to it. When I turned the key it showed 0 volts. So I need to figure out what is cutting off the 12 volts going to the solenoid relay. I read some threads (98 S70, latigerlilly/Ozark Lee and 99 V70, steveo/OL) that removing and bypassing an "immobilizer" relay (relay 210/211) high inside the drivers side of the car could be a solution. However, my car apparently doesn't have that relay, at least I can't find one with that number in that area. There are 4-5 relays in that area but none with the right number. If the problem is the PNP, it has no other symptoms. I haven't been able to trace the wiring from the starter switch to the ECU to the PNP, but I'm hoping somewhere in there is a relay or kill switch that I can bypass. I can always run a wire directly from the key switch 50 connector to the solenoid, which is maybe where it should be, but I'm not that desperate yet (I'm getting there). Luckily I have my 91 Camry that is boring but never quits starting and running.

Any ideas about what to try next or how to find the "immobilizer"?