Engine: B5244: Starter motor sticking engaged

[Alisims1989]

Originally Posted by Jim314

Is it possible, advisable, and safe to pull up the relay so that it is still making contact with all four pins, but be able to jump the ignition switch side to ground to complete the circuit and actuate the relay to close the circuit to the solenoid?

Jim, unless the key is in position 3 the ignition circuit is broken so shorting it to ground will make no difference.... I think!

[Jim314]

Originally Posted by Alisims1989

Guys,

That's what I am jumping as per diagram 2 the 2 fuses is one 25a fuse and one fusible link, not listed in my Haynes manual as to current rating.

I also tested the PD between ground and the starter and there was still 9 volts there

I think the 3 V loss (12 V to 9 V) must be due to internal resistance in the battery. If you put a voltmeter across the +12V post in the engine compartment to the engine ground, I think you will see a drop from 12.4 V to 9V when cranking the starter.

[Alisims1989]

Originally Posted by Jim314

I think the 3 V loss (12 V to 9 V) must be due to internal resistance in the battery. If you put a voltmeter across the +12V post in the engine compartment to the engine ground, I think you will see a drop from 12.4 V to 9V when cranking the starter.

I tried a brand new battery from a parts store the other weekend though and the same thing happened!

I'll have to do some more investigating, I haven't seen the voltage drop whilst cranking on pin c in your schematic, could be resistance in the eye connection to the positive post in the engine bay

[Jim314]

Originally Posted by Alisims1989

Jim, unless the key is in position 3 the ignition circuit is broken so shorting it to ground will make no difference.... I think!

If you look at the circuit diagram, the ignition switch on the steering column closes the circuit on the ignition switch (by connecting to ground) which then magnetically closes the switch (in the starter relay) which actuates the starter solenoid. The diagram shows no other switches in the circuit. So grounding the correct pin in the starter relay would be the same as turning the ignition switch to position III, as far as actuating the starter.

However, turning the ignition switch from Position II to Position III does other things beside actuating the starter relay. In Position III all other electrical loads not necessary for the engine to run are disconnected (lights, a/c fan, radio, heated seats, instrument panel lights, . . . ) so that nearly all the power from the battery is directed to running the starter motor. The result is that if one runs the starter motor with the ignition switch in Position II, then any of these other loads that are on will be drawing current. We can turn off all these accessories except the daytime running lights, which can be turned off by turning on the parking lights.

In one of my previous cars (1991 Dodge Spirit) the ignition switch went out--it would turn to the run position but not turn the ignition switch from the run position to the start position. I pulled the starter relay and for a few days I started the engine by putting the ignition switch in position II, opening the bonnet and shorting across the starter relay socket on the solenoid side. I cannot remember if I ever tried to ground one pin on the other side of the starter relay for testing the starter relay. I am not in the habit of grounding a point which is at +12V because one must be sure that the resistance load is between that point and the battery. If the circuit diagram is correct, this is the case for the ignition switch side of the starter relay. However grounding the wrong socket pin on the ignition side would blow fuses or a fusible link, assuming the circuit diagram is correct and I am understanding it correctly.

[D5meister]

Im getting in a mess here, as theres 2 guys with different problems.

Thread owner has a sticking disengage - either sticking or some power left to solenoid after key release..
Other guy when jumps line to solenoid all works, Replace FS2 sometimes they go lazy

[2.4TSE]

Thread owner here! The car has now been serviced and the starter motor removed and refitted after cleaning the pinion assembly as requested. To my surprise, not a jot of difference. If the engine is stone cold in this winter weather the starter motor still nearly always emits a brief "krrrrk" after its done its job despite the solenoid signal being removed correctly. If the engine is even the slightest bit warm, no "krrrrk". Ever.

Garage is almost completely certain that it is because the bush on the pinion end of the starter motor shaft is worn. That's a new one on me but I'll continue to live with it and if it gets audibly worse, replace the starter motor before it fails. I'm not going to bitch after 12 years of ownership of a staggeringly reliable car.