Engine: B5244: Starter motor sticking engaged

[Alisims1989]

I looked at mine again today, has been sitting on a trickle charger whilst I look through the system so battery is at 410 cca, verified by GSF this weekend. Through turning the key the cranking is slow, then the car splutters into life and is fine after that. When I turn the key to position 2 then Hotwire the signal cable on the starter the starter runs a lot better! Any ideas guys?

[Jim314]

Originally Posted by Alisims1989

I looked at mine again today, has been sitting on a trickle charger whilst I look through the system so battery is at 410 cca, verified by GSF this weekend. Through turning the key the cranking is slow, then the car splutters into life and is fine after that. When I turn the key to position 2 then Hotwire the signal cable on the starter the starter runs a lot better! Any ideas guys?

Does the V70 have a starter relay in the fuse box in the engine compartment? If so, I would remove the relay and start the car by putting the key in Position II and then shorting the two contacts in the starter relay socket which actuate the starter solenoid. If this causes a normal actuation of the solenoid, then the solenoid is OK and the fault is in the starter relay (easiest to replace) or the ignition switch (easy to replace).

[Alisims1989]

THanks for the help Jim, If i have to replace the ignition switch wont I have to get one from volvo to suit my key pattern, or can i get a second hand one?

Ali

[Jim314]

Originally Posted by Alisims1989

THanks for the help Jim, If i have to replace the ignition switch wont I have to get one from volvo to suit my key pattern, or can i get a second hand one?

Ali

The ignition switch is different from the ignition lock assembly. The ignition switch is actuated by the ignition lock. The lock is trouble and expensive to replace, but the switch is easy and cheap.

The ignition switch contains the contacts which actually do the switching and contains the return spring to spring the key back to position II from position III.

The ignition switch is fastened to the other end of the ignition lock from the key end by two (three?) torx screws. To access the switch, remove the two-part plastic shroud from around the steering column, unplug the wiring harness to the switch, remove the two torx screws, and the switch comes right off. You do not have to disconnect the battery, but should have the key removed from the ignition lock. Just be sure the new switch is in Position 0 so that the receiving socket meshes with the rod from the lock.

As easy as it is to replace, don't change the ignition switch until your testing has shown it is faulty. My guess is that the fault is the starter relay in the fuse box in the engine compartment.

[Jim314]

Just looked at my V70, according to the sticker on the inside of the cover of the fuse box in the engine compartment it appears the starter relay is designated FMA4. One can pull this relay and using say a 6" to 12" length of 12ga solid house wire manually make the connection to start the car. Note that there are four points of connection and you want to jump the correct two to actuate the starter. If you do it wrong, you could blow a fuse or worse.

Two of the connection points go to and from the ignition switch, and two go to the starter; it is the latter two you want to short to test the circuit from that point. With the relay out you would put the key in the ignition and twist to position II, the run position. Then use the jumper wire to connect the two connection points in the socket which go to the starter. Just firmly touch the ends of the wire to the connectors in the socket, don't jam them in because as soon as the car starts you want to be able to pull the wire away.

[Alisims1989]

Jim, I'll have a look when I get home and see what I can see. I have seen some videos about how to check the function of the relays but is there a way to check the ignition switch?

[Jim314]

You would need a wiring diagram to check the ignition switch. Basically the switch just shorts wires, and so connects +12V to various wires which then power certain devices which then pass current based on the resistance of the device.

To test the switch the old-fashioned simple-minded way one would disconnect the wiring loom from the switch, then use a multimeter in the resistance mode to determine that the switch shorts each connection it is supposed to in each switch position (0 through III).

But this is not the full story because it is possible (though not likely) that under load (full current) the switch could fail by having higher resistance than without load.

One can test simple components like the relay and the switch by just substitution of a new one and seeing if the faulty behavior was no longer present although this is disparaged as unfrugal and mindless.

[Alisims1989]

so the problems are persisting, tonight I changed the starter switch for a "functioning one" that I got from a breaker on eBay. The same problem as I am currently having persisted, very slow crank, similar to that you get when power is low from the battery, then it comes to life!

By shorting the starter signal wire with the positive terminal by the fuse box the engine cranks like new and spring to life nearly instantly.

I have checked the resistance on the relations, 75ohms on the ignition circuit and negligible on the starter circuit I have also applied white grease to the connection between the loom and starter motor and the signal wire as I know this can get corroded, but this hasn't helped

The only other things I can think to do is test the resistance of the wires in the circuit from the ignition switch all the way through to the starter unless there are any other ideas?

I have seen that there is a fusible link in this circuit, could that have gone?

Thanks in advance

[Jim314]

Originally Posted by Alisims1989

so the problems are persisting, tonight I changed the starter switch for a "functioning one" that I got from a breaker on eBay. The same problem as I am currently having persisted, very slow crank, similar to that you get when power is low from the battery, then it comes to life!

By shorting the starter signal wire with the positive terminal by the fuse box the engine cranks like new and spring to life nearly instantly.

I have checked the resistance on the relations, 75ohms on the ignition circuit and negligible on the starter circuit I have also applied white grease to the connection between the loom and starter motor and the signal wire as I know this can get corroded, but this hasn't helped

The only other things I can think to do is test the resistance of the wires in the circuit from the ignition switch all the way through to the starter unless there are any other ideas?

I have seen that there is a fusible link in this circuit, could that have gone?

Thanks in advance

Have you ruled out the starter relay? (By starter switch do you mean starter relay in the fuse box?) If you remove the starter relay and then jump across the two contacts which close the starter solenoid, does the engine crank strongly?

[2.4TSE]

I'm with Jim on this: The starter relay has to be the next step in troubleshooting. From what you describe there is indeed a high resistance, most likely on the "heavy duty" side of things but also possible on the "low duty" - which then causes a "heavy duty" high resistance through not closing properly. By "heavy duty" of course I mean the feed to starter motor coil windings, not the feed from the ignition switch (which is the "light duty").

If replacing the relay (simple) does not solve the problem then we can look further.