Technical Voltage regulator behaviour

[Stxox50]

Hi

I have a 1971 Fiat 500L and have recently we have run into some problems with what seems to be the voltage regulator with the symptom being the behaviour of the light on the dash.

The first thing we did was test replace the traditional voltage regulator one with a new electronic one. When the engine revved, the dash light would dim but not go out.

After this we went back to the traditional electromechanical device. We noticed that the contact for the 51 terminal was a little bit out of alignment so tried to realign it. After doing this the light went out if we increased the revs a bit, but then turned back on at very high revs.

I wondered if anyone had any comments on the following.

What can be the reason the light didn't go out fully using the electrical voltage regulator?

Is it normal that when using the traditional electromechanical voltage regulator, that the light returns at higher revs. We wonder if the contacts are somehow damaged and arcing.

Any insight would be welcomed.

Regards

Steve

 

[bugsymike]

Hi

I have a 1971 Fiat 500L and have recently we have run into some problems with what seems to be the voltage regulator with the symptom being the behaviour of the light on the dash.

The first thing we did was test replace the traditional voltage regulator one with a new electronic one. When the engine revved, the dash light would dim but not go out.

After this we went back to the traditional electromechanical device. We noticed that the contact for the 51 terminal was a little bit out of alignment so tried to realign it. After doing this the light went out if we increased the revs a bit, but then turned back on at very high revs.

I wondered if anyone had any comments on the following.

What can be the reason the light didn't go out fully using the electrical voltage regulator?

Is it normal that when using the traditional electromechanical voltage regulator, that the light returns at higher revs. We wonder if the contacts are somehow damaged and arcing.

Any insight would be welcomed.

Regards

Steve

In the old days with dynamos I would have said the brushes in the dynamo had worn out with the dash light symptoms.

 

[Stxox50]

The engine we have is a reconditioned one, and the dynamo brushes were replaced during reconditioning so we dont think it is that. We can see the voltage rise if we disconnect the wires and short the two terminals up to 40V.

As such we think the dynamo is behaving itself.