Starter motor constantly spinning??

[Darren C]

Just went to fire up my car as it's a nice crisp day at last, but the starter wouldn't spin; battery amps showed low, so I put her on charge....

Came back, starter didn't turn the at first (made a whirring noise??) then she started to turn over. I took my finger off the starter button but the engine carried on turning over. I turned off the ignition and she was still turning over, so I had to isolate the battery supply. When I reconnect the battery, the engine starts to turn over straight away, even though the ignition is off.

Only when the starter was spinning did I notice that the earth connection must have been slightly loose and was arcing slightly.

Is this likely to be the relay or solenoid? How do I test for either?

Any help would, as always, be very, very much appreciated!

Cheers


Darren

 

[Jim Cowden]

Darren

More likely solenoid could have welded itself across terminals because of bad earth.

If your primary wire to solenoid has 12 volts when the key is in the run position, it will be ign switch or relay or something at that end.

I have seen solenoids weld themselves due to bad earths.
It generates high amp draw, the weld will be the tiniest of spot across the contacts.
Tapping the solenoid may release it.

Jim

 

[Randy V]

I agree with Jim and have seen this a number of times. Countless Ford Starter solenoids have had the crud beaten out of them because a poor ground had caused the contacts to weld. Same thing with Horn Relays..

 

[Robert May Eng.]

This happens on trucks if the battery is low and the draw is high as in cold conditions , it is referred to as induction lock. Normally the only way to stop it melting everything including the starter and associated wiring is to turn off the battery isolator or get a lead off the battery ( not recommended). If the battery is up to the job and the starter is in good condition it wont happen.

The other thing that can hold in a starter is a tight mesh between the ring gear and the starter gear.

Bob

 

[Darren C]

So, it looks like I've accidently welded my solenoid, which would explain why the starter fires as soon as the safety cut-out is turned back on, regardless of whether the ignition is on.

Is it possible to fix the solenoid, or should a firm 'tap' sort it?

Thanks for your help!


Darren

 

[Jim Cowden]

Darren easier with 2 people, you need to test the primary side first to confirm.
Hook the battery and pull the primary wire on the solenoid first, if it still turns over yes its the solenoid.

If its old school and you can pull the solenoid apart and clean the contacts with a file or emery thats good.

If its in a bitch of a spot and your feeling lazy give it a tap and see if she comes good.
If it frees and you can do a 20 start test with no issue run with it and see.

Jim

 

[Randy V]

While you're at it - it would be adviseable to check the condition of all battery cables, ground cables and their contact / connections to make sure they are clean.. Else you may just be right back in the same position again. Most solenoids have retaining nuts on the large terminals that you can loosen slightly. When you do that, the weld to the contact disk inside pops loose immediately in most cases.