1998 V70 Starter won't crank with Ignition Key

[bluehawk]

1998 V70 Wagon with Turbo 185K miles

Sudden onset. Engine would not crank with ignition key. Wife got towed home......but got to ride in air conditioned tow truck. Minor consolation.

All the instrument cluster functions appear normal with one possible exception (discussed later). I was able to get the Starter to crank .... first, by jumpering +12v from the Battery to the Starter Solenoid and subsequently by jumpering across receptacle slots 1 (Relay pin 30) and 3 (Relay pin 87) at the Start Relay receptacle in the Relay box. With the ignition switch "On", the engine would start and run, when the Starter was cranked by jumpering. Trouble is it takes two people to start the car that way, and it's not good in traffic.

The one "exception" on the instrument cluster, which may not be an exception, is that the red SRS light cycles on when the key is held in the "Crank" position. Maybe it is supposed to and has been doing that all along?

Another anomaly that mostly likely occurred with the onset of the starter problem, is that the passenger doors will no longer all lock/unlock when the driver's door lock is manually locked/unlocked with the key. The electric door lock control on the driver's side door has been kaput for sometime, but the "manual" lock issue is new. So, most likely, resetting the Computer by cycling the driver's door lock will accomplish nothing. I disconnected and reconnected the battery and tryed anyway ........ to no avail. Also tryed cycling the shift lever from Park to Low several times and tryed starting in Neutral. No luck there either.

I read voltages and resistance at the various Start Relay pin receptacles in the fuse box, with key OFF, and ON, and in "Crank" mode but without knowing what controls what, it is a bit difficult to interpret if all is functioning correctly. I did NOT measure voltage at the Starter Solenoid with the Start Relay in place. It would seem that there is none....... otherwise it would crank. Maybe I should?? If someone has a detailed discussion on Start Relay function, pins, voltage, and resistance, I am all ears.

Seems to me to be a "security" or immobilizer problem. Or maybe the Shift Selector Sensor. I might buy a new Start Relay and try that. I really don't care about the security thing. If someone steals the car they would have to be really hard up and might be doing me a favor. Hasn't happen yet. So if there is some way to get the car to crank and start by key by disabling the security system, I am amenable. Anyone have any ideas??

[rspi]

You likely have low volts to the solenoid. I had the same issue a few months ago. I took the positive battery cable apart and cleaned between all of the wire connections with a wire brush and I have not had an issue since.

[BEJinFbk]

I think you're on to something suspecting the security system.
The relay that you bypassed sounds like the 2/35 starter relay.
And if you're locks are also inop, I'd suspect there's a connection.
Both are controlled by the 2/76 Central Locking/Anti-Theft Alarm.

The lock/alarm provides a ground to the starter relay coil, pin 85,
when it's disarmed and the ignition switch sends 12 volts to the other
side of the relay coil, pin 86, when you turn the key. When the relay
coil is energized, constant 12 volts on pin 30 is connected to pin 87
and that runs to the small green wire at the starter.

Is your fuel door switch working? It also runs through the lock/alarm module.
It probably won't help, but have you checked all of your fuses?
2, 6 and 13 all connect to the lock/alarm module.

[bluehawk]

Hi BEJ - Good info. I have been scrutinizing the schematic. Car door "Auto" lock function quit working at the same time as the No Crank problem started. Working the key Manually in the Driver's Door Lock
has no effect on the Passenger Door/ Lift Gate Locks. The Fuel Cap Door release quit working some time ago. I will check the fuses again. For now, I will likely jumber pin 85 to ground, so the vehicle can be used.

Thanks!

Bluehawk