960: no crank/no start

[mschultz373]

960 sat for five days and now suddenly won't crank. All accessories turn on, but car only clicks when turning the key to crank/start the car. car started and drove normally before.

the issue is intermittent. it started up fine early today several times - now it won't start again.

battery is at 12.2V at rest. (not super relevenat but the only measurement I have) and there's secondary air injection code currently in the module.

I am suspecting either the ignition switch or the security system. I am not super familiar witht he security, but I understand it can be squirrely with the different keys and all.

Any pointers are helpful. thanks.

[apachechef]

Battery is at 50%
Clean your terminals and grounds, jump the car, and ensure 13+v when running.
You know, basics

[2manyturbos]

The key makes no difference as long as it turns the lock. 960, S, V90 keys are not chipped. There is a relay for the starter in the relay box under the hood. The relay may be getting flaky.

[Kjets On a Plane]

Is the alarm aftermarket?
No immobilizer / chip keys on those.

Crummy starter/starter relay, crusty battery terminals, or bad ignition switch or relay? Battery volts / charge?

Will it light a 12v 20w test light (like one from one of the tail light bulb holders) at the small starter spade terminal or Volvo factory starter clicker female spade terminal? (I forget where they hide that on late 960s…earlier 240 & 740s they hide that by the main engine harness plugs, but as the years went on they reduced the # of connections to potentially get wet/fail.

Conversely, does the starter crank if you bypass the ignition switch / apply power to the spade?

If it has been sitting might want to verify the timing belt is totally intact / looks good on an interference engine?

[mschultz373]

[deleted]

[mschultz373]

all the relays are good. verified with a 9V battery + i can hear them switching when the key is turned at the ignition. i also swapped a couple of them into the starter relay and it didn't make a difference. that makes me think the ignition switch must be good.

so I am left to troubleshoot the starter and battery. i am having a hard time find/accessing the starter in this engine bay but when I do I will try giving it voltage directly.

[mschultz373]

tried jumping the battery and nothing changed. hit with the key - clicks but no cranking. i am suspecting a bad starter at this point.

[2manyturbos]

Sounds like it to me based on everything you’ve done so far. The starter is not difficult to replace on a 960.

[ZVOLV]

Last step is to congfirm power to the starter signal wire with a TEST LAMP.

You should also voltage drop test the cables too. There is a chance you have a loose or corroded cable.

[mschultz373]

well it is NOT the starter after all.

I gave a spare key to my girlfriend to try to start the car while I was at a recording session. She said the alarm went off, the car would not start in P nor N, but all the accessories turned on.

I came back over and the car started right up with my key, unlocking it with the fob to get in the car.

I went ahead and replaced the ignition switch with another one i have (unsure how I could check the removed switch with a dmm?).

Starter is getting 12.45V constant from battery and measures 280-300mV drop after cranking, with engine running; it measured 60mV or so of volt drop while cranking. I did not volt drop the negative side.

I am suspecting either the park-safety switch or something in the security system.

[ZVOLV]

Originally Posted by ZVOLV

Last step is to confirm power to the starter signal wire with a TEST LAMP..

So? Have you confirmed a test lamp illuminates on the little wire to the starter when trying to crank?

[mschultz373]

yes, the test lamp illuminates on the signal wire when cranking and starting the car.

[mschultz373]

i am inclined to think this is a problem with the immobilizer/security system.

whenever the alarm goes off - using one of the spare keys or something (not sure why that happens either) -, locking and unlocking the car does not stop the alarm on the first try. it typically requires several cycles of locking/unlocking to disarm the alarm.

additionally, and you'll think I'm nuts - i swear the fob nor the lock/unlock button by the steering wheel do not work anytime I park in this block downtown. Without fail, both will work normally everywhere else and stop working when I park in this one block. i think there must be some weird signal or wave coming from one of the businesses that impacts the computer.

call me crazy, but this is where i'm at.

[Janspeed]

often an alarm system has a small rechargeble battery in it. It's there to ensure that alarm still works when the car battery is disconnected.
I'd check and see if that internal battery is on it's last leg. Could also be that the battery in the key fob is nearly empty.

BTW 12.2V for a car battery is kinda low. A properly charged healthy battery (without loads on it) should show about 12.6V on the meter

[ZVOLV]

Originally Posted by mschultz373

yes, the test lamp illuminates on the signal wire when cranking and starting the car.

Does the test lamp illuminates when it is a NO CRANK?

[mschultz373]

No, the signal wire does not illuminate if there is no crank. It seems like now I can typically use the shift lock override button to take the car out of park and put it back in and it will then start. The signal wire illuminates any time the car is cranking.

[ZVOLV]

That sounds like a PNP switch issue.

You need to continue circuit diagnosis...