TR4 Starter/Electrical Problem

[LarryS]

When I start my TR4, the engine starts normally, but in addition to the sound of the engine I hear a high pitched whine which sounds like the starter motor still running at high speed. It seems that it has mechanically disengaged from the engine, but is still running. My first thought was that the fault might be in the ignition switch and that the circuit to the starter was still complete even though the switch was not being held in the start position. Is this likely or should I look for a fault in the starter mechanism? The starter has never been serviced. I did try repalacing the starter solenoid, but that did not help. Thanks for your help. Larry

[tr-pete]

hi larry - one thing you could try is to wire the starter motor direct to the battery - obviously removing the main starter wire once it had started . that would then bypass the ignition switch and the solenoid, if the noise then disappears it would indicate a fault with the switch or solenoid, if the noise continues it would indicate a fault with the starter motor....... i have a similar problem with a modern lorry of mine, after starting the lorry and letting go of the key you get a terrible whine from the starter motor for about 5 seconds as the bendix disengages slowly down the shaft- if this is what you have i believe you have to take the starter out and clean and lubricate the shaft where the starter flies up. however - make sure other members recommend what i say - im not a mechanic, its just my cowboy mechanical knowledge of problems.

[bob-menhennett]

Larry

I'd say it was the starter motor Bendix not returning to it's rest position because of dirt,needing a clean.If the large spring were broken it would be more of a "clatter" rather than a "high pitched whine ".

Disconnect the battery BEFORE removing.

Take out the starter from the car...it's heavy so don't drop it, when you remove the second bolt.Use an old paint brush and something like meths (metholated spirits) or a degeaser to clean the exposed shaft and Bendix.Hold the body uppermost and the shaft down, so that the cleaner drains away from the electric motor.An old newspaper will catch the liquid and dirt.With an open palm, spin the Bendix ,once the shaft is dry and check it quickly returns to rest, without drag.

Do not oil or grease it !! It will attract dirt and will play up again.. very quickly.

If everything is working OK, replace in the car making sure that the bolts and main cable connections are tight.Re-connect the battery and test operation in situ.

 

Bob

[BrianC]

If everything is working OK, replace in the car making sure that the bolts and main cable connections are tight.Re-connect the battery and test operation in situ.

 

 

Whilst it's out, you may as well check and replace the brushes if more than half-worn. You really won't want to do this job again in a hurry.

[ianc]

It could be the ignition switch if the spring within the switch fails to return the switch to the "run" position from the "start" position. This happened to my wife's Citroen AX, and we had to remember to turn the switch back to the run position after starting the car, else we had that whirring sound.

 

You can check whether this is the problem by connecting a multimeter between the solenoid terminal and earth, starting the car (12 volts should be seen on the meter as soon as you turn the switch to "start"), then see whether that 12 volts disappears when you release the switch to allow it to return to the "run" position. If the 12 volts remain, then it's the switch which is faulty. This is an easy test, and should be done before you start the process of removing the starter! If you haven't got a multimeter to hand, use a 12 volt bulb, such as one from the instrument panel or sidelamp.

Ian Cornish

[LarryS]

It could be the ignition switch if the spring within the switch fails to return the switch to the "run" position from the "start" position. This happened to my wife's Citroen AX, and we had to remember to turn the switch back to the run position after starting the car, else we had that whirring sound.

 

You can check whether this is the problem by connecting a multimeter between the solenoid terminal and earth, starting the car (12 volts should be seen on the meter as soon as you turn the switch to "start"), then see whether that 12 volts disappears when you release the switch to allow it to return to the "run" position. If the 12 volts remain, then it's the switch which is faulty. This is an easy test, and should be done before you start the process of removing the starter! If you haven't got a multimeter to hand, use a 12 volt bulb, such as one from the instrument panel or sidelamp.

Ian Cornish

 

[LarryS]

Thanks to everyone for your suggestions.

I decided to try Ian's suggestion first since it did not require removing the starter. I started the car from cold and it had not been run for several weeks, so it would have required about 10 to 15 seconds before the engine caught. I tried cranking the engine for two to three seconds at a time and releasing the ignition from the start position. When I did this, the starter stopped cranking as it should have. It seems if the ignition switch was faulty, the starter would have continued cranking. When the engine started, it ran normally for a second or two and then the high pitched whine started. I let the engine die by pushing the choke in and the whine continued. I measured the voltage at the starter terminal and it was getting 12 volts. I then turned the ignition to off, which removed the power from the starter. Apparently, power is being applied to the solenoid after the engine starts. I am considering replacing the ignition switch although I do not have a definate indication that it is bad. I have not done any work on the electrical system recently other than replacing the solenoid. Any thoughts?

 

Larry

[Smokey]

Faulty solenoid?

[LarryS]

Faulty solenoid?

 

I replaced the solenoid and that did not help. It is new but is the original type with the pushbuttton. I could use the pushbutton to start the car and see if that makes a difference.

 

Larry

[LarryS]

Faulty solenoid?

 

I just used the pushbutton on the solenoid to start the car and had no problem, no whine. I am thinking it must be the ignition switch or the wiring to the switch.

 

Larry

[ianc]

Over the many years since the car was built, the ignition switch will have worn, and it sounds as if yours is failing to disconnect the feed to the solenoid when it (supposedly) has returned from the START to the RUN position. It's just possible (though not too likely) that there is an external short across the two terminals on the ignition switch - far more likely that it's just worn out! In which case, just change the switch (you might be able to swap the barrel, so as to be able to use your existing key - I've never tried this, by the way).

On occasion, the barrel comes out of my ignition switch when I withdraw the key - again, old age!

At least you won't have to remove the starter, from what you say.

Ian Cornish

[RogerH]

Hi Ian,

I believe that the switch comes without the barrel so making change necessary.

 

Roger

[Tr4Tony]

Hi

 

The LUCAS ignition switches do fail regularly, Ive had one burn out in traffic (modern green box) and had one fail on my on the way into the first Test on LEJOG in 2007 and it took me 16 minutes to change it in the middle of a special test ...... complete pain, but sound very much like this is the problem. Next sympton is smoke and complete failure ..... maybe even a wiring fire, so something to deal with really soon.

 

Tony