Perkins Prima M50 stop solenoid and tachometer

[steve.garlick]

Hi all,

Request for some diesel engine advice.

I've tested the solenoid circuit, and the voltage rises from 1.45 V to 14.5V when the stop button is pressed, engine running. I conclude that the problem is not a faulty circuit preventing the engine from stopping, but the stop solenoid.

The shop manual doesn't cover the solenoid, any issues with unscrewing it? Is it easy to drop in a replacement?

The tacho has also stopped responding. Are there any common failure points? I will check the connections on the back of the instrument panel and the wiring harness. Any other obvious failure modes?

Regards,

Steve

[donradcliffe]

Where did you test the voltage?? You should start at the solenoid, and it should go from zero to 12-14v when your helper presses the stop button. If the tach has failed at the same time, I would also be looking at the plugs in the wiring harness for corrosion.

[steve.garlick]

Thanks Don,

I tested the voltage beween the solenoid and its single connecting wire. resting voltage was 1.45 switching to 14.5 when teh stop button was pushed. I will check the wiring harness, also behind the instrument panel, if only I can figure out how to get it out!!