Starter Motor Problem?

[Tazzzzman1]

At long last I have the old gal back on the road and running...well almost!

I seem to be getting issues starting her when when the engine is hot.

 

When cold the starter motor kicks in and hey presto..

When hot the starter motor does not work. After checking voltages, it seems taht I am only getting 6-7Volts to the starter when connencted (on the switched wire), when I remove the wire from the starter I get 12-13volts.

If I leave the engine 20-30 mins to cool down then starter works again..

Really strange as it is only doing this when the engine is hot. The starter is new. This issue is very similar to the problem I had with the old motor.

Any ideas as to what the problem may be?

[Guest russell555]

had the same fault and it turned out to be loose battery terminals

[speedtripledan]

Check all your chassis earths or run an extra one to the starter. Is the starter clicking in or just totally dead when trying to start hot?

[Guest Peter Kelly]

Check that there is a good earthing wire from Engine block to frame and the same from battery to frame.

[Tazzzzman1]

Check all your chassis earths or run an extra one to the starter. Is the starter clicking in or just totally dead when trying to start hot?

 

Hi Dan,

 

I can hear the starter solenoid trying to energise, but with only 7V on the switch wire it's not energising fully to kick in the motor.

I have checked earths and all seems good.

As I said before, starter works perfect when cold (12v on switch wire). Only have the issue when it gets hot...I'm thinking a problem with the motor which is causing high resistance when hot (which is killing power)

 

Keep the thoughts coming....

Ta

[speedtripledan]

Hi Dan,

 

I can hear the starter solenoid trying to energise, but with only 7V on the switch wire it's not energising fully to kick in the motor.

I have checked earths and all seems good.

As I said before, starter works perfect when cold (12v on switch wire). Only have the issue when it gets hot...I'm thinking a problem with the motor which is causing high resistance when hot (which is killing power)

 

Keep the thoughts coming....

Ta

the volt drop could be due to the starter being under load and not receiving enough amps. i would try using a jump lead to the starter when the problem occurs if it fires over then u know its a circuit problem...

 

 

 

[johnlrichardson]

As notimpressed said earth from s/motor to the one on the bellhousing

 

HTH jon

[nigelt]

When you measure the voltage at the starter motor, where are you puting the ground lead for the volt meter?

 

Are you puting the ground wire against the engine/casing of the starter motor or the chasis?

 

You either have a starter motor that is drawing a huge ammount of current (when hot) to cause the volts to drop to 6-7v

or more likely you are getting some high resistance in the feed to the starter motor.

 

As the battery is near as damn it connected directly to the starter motor you would expect to see the battery voltage drop to 6-7v if the starter motor was drawing a huge amount of current. More than likely you will see this is still around the 12v. So you either have a 5-6v drop between the Battery and the starter motor (this could be through the starter relay!). Or you have a 5-6v drop between the earth side of the starter and the battery negative terminal. Hence it depends on where you are placing the negative lead of the meter as to what you are measuring.

 

Try measuring between battery negative and negative terminal of Starter. If you see 5-6v between these you have an earthing problem. Measure between battery positive and the starter positive. If you see 5-6v you have a high ressistance in the feed to the starter.

 

Hope that helps

 

Nige

[fry61]

Check battery voltage (across batt.terminals) when cranking first; to make sure the battery is delivering 12volts under load;you may have a duff cell which only shows up under heavy load.

[Guest mower man]

Much in agreement with last post do as said or get battery 'drop' tested should realy be holding 12v mower man [been there ,starter alternator bad earths cure new premium battery dho!!!!![

[Tazzzzman1]

Thanks for the feedback.

I have placed a feed direct from Battery negative to the starter. All seems okay at the moment, so fingers crossed.