Starter Problems ...

[ericbushby]

Alan,
It may be that the solenoid current is higher on the modern pre-engaged starter because it has more work to do. It has to push the pinion into engagement with the starter ring and then switch the motor on.
Cheers
Eric

[Galwaylotus]

UPDATE: I removed the starter and brought it to an auto electric workshop to have it tested. I was told to leave it and was asked for my number. I didn't hear anything all day so I returned late in the day to be presented with a bill for ?102! I hadn't asked for anything more than testing but since I hadn't specifically said I didn't want anything else done before consulting me I felt I probably had to pay.I was assured it was working "100%". I refitted it this morning and ran new cables to a 40A relay to ensure the load on the ignition switch wasn't excessive. I had measured 35A when energising the solenoid on the bench. The connections were all made and I checked voltage at the various points in the circuit. When I tried to crank the starter, however, I still got nothing. I Put 12V directly to the solenoid and sometimes heard a click but not every time. The starter never turned. The starter is a Kelvedon "Lightweight Starter Motor" with piggyback solenoid. It had been working perfectly until I had this problem last week. It had a couple of dodgy starts but eventually would go until last Thursday. I got it to the point today where the new relay will chatter when the ignition is turned to START but nothing more. I checked resistance across the relay switch contacts when the coil is energised and read half an ohm or less. There is just under 12V going to the solenoid via the new relay. I even tried bypassing the relay and applying full battery voltage (12.5V) to the solenoid but without any result.

Before I go back to the electrical workshop to demand my money back, am I missing something? Could there be another reason the starter won't operate?

[john.p.clegg]

Battery U/S or dodgy high ampage connection..

John

[alan.barker]

Is earth from oil pump screw to chassis good, also battery earth in boot to chassis
Alan

[Galwaylotus]

Battery U/S or dodgy high ampage connection..

John

Battery is fairly new and shows 12.65V when fully charged. It's down to about 12.5V after my testing but it's fine.

[mbell]

I'd run a new earth direct from engine to battery for testing, a jump lead or something would do the trick.

[bob_rich]

Hi

The solenoid on the starter motor has to push the pinion into the flywheel ring gear. At the end of it motion it connects the main 12V to the motor. It may not be fully engaging for some reason and so the motor is not energised. As the other posts say a bad earth to the engine could cause the voltage to drop. The test meter reading on 0.5ohm is not really valid as the resistance should be only a few thousanths of an ohm. the half ohm is probably the meter leads and contact resistance effects

Can you set it up on a bench with the motor held ( very firmly ) in a vice and then wire as a similar circuit as shown in my earlier post on Friday 14th.

This should allow you to test it and see what is happening. A voltmeter across the battery ( If in a good state of charge) terminal should read around 12.4V with no load. Around 11.5V to 12V motor solenoid only and no less than 8V if the motor energises and spins up. If the voltage goes very low then maybe the motor is shorting and causing the voltage to dip

If it spins up OK on the bench then maybe the movement on the pinion is not fully extending in the car and so the final stage of switching on the motor on isn't occurring.

Regarding the fee you paid that seems a bit steep. If you go back stay and observe the test and I would not pay any further monies over. especially if the motor has a fault.

Hope this helps best of luck

Bob

[Galwaylotus]

Is earth from oil pump screw to chassis good, also battery earth in boot to chassis
Alan

Both checked and secure.

[Craven]

Ask the auto electric workshop how they tested your starter and could they demonstrate it working.

[Galwaylotus]

Thanks for all the suggestions, folks. I'll make another attempt tomorrow. I'll try running a jumper cable directly from the starter motor to battery earth terminal and see what that does. If it doesn't make a difference I guess I'll have to remove the starter (again!)

[EPA]

If the relay chatters (i.e. Doesn't stay engaged )then the act of closing the circuit to the starter is causing the voltage to drop at the relay which is why it disengages. This removes the circuit to the starter and the voltage to return to normal thus rengaging the relay and the cycle continues causing the chatter.
This has to be either the battery breaking down under load or a bad connection somewhere in the high current wiring between the battery and the starter. In this I include all the earth connections starting with the connection to the chassis at the battery end and the straps from the chassis to the engine.
If you put a voltmeter acros the battery and try to start does the voltage stay at around 12v?
If you only get a small drop in voltage then this suggests that the battery is ok
Check the voltage across the starter when you try to start (use the case of the starter for the ground for your meter)
If the voltage is low or drops significantly then there must be a bad connection somewhere in the circuit (assuming the starter is ok).
If this is the case I would remove and clean each connection in turn starting with the ground connection to the chassis from the battery.
Remember the fact that your meter shows a good circuit does not mean the connection can take the large current required to start the car, a bad connection tends to go high resistance when these sort of loads are applied.
If you can connect to either side of a bad connection and measure the voltage across it at the moment you turn the start key you would see a voltage reading due to it going high resistance.
Ed

[2cams70]

You need one of these kits to switch the load to the pre-engaged starter motor solenoid. It will reduce the switching load on the ignition switch to less than one amp - i.e even better than keeping the starter solenoid for the original "bash in" type starter in circuit.

http://www.ebay.com.au/itm/Starter-Moto ... Swax5Ym-DJ

[billwill]

Is earth from oil pump screw to chassis good, also battery earth in boot to chassis
Alan

Both checked and secure.

It's not merely secure that you have to test. It can be tight but with an insulating layer of paint or rust preventing a good connection.

[alan.barker]

Have you tried a new earth wire from the body of the solenoid to a camcover stud as i suggested yet.
I have had this problem several times. bad earth to solenoid body.
good luck
Alan

[EPA]

I meant to also mention that you shouldn't assume that crimped connections to cables or earth braids are good just because they appear tight. These can also corrode over time and cause this type of issue.

Ed