Low voltage at clutch

[jeepsj]

In diagnosing everything, I'm only getting about 11v to my compressor clutch. Could that be part of my clutch slipping problems? Where should I start looking to find the voltage draw?

1987 Chevy R30, 7.4l.

[emsvitil]

You could rewire it so that the existing wire to the clutch turns on a headlight relay that then gets it's power directly from the battery.

[Dougflas]

verify your meter is reading correctly by measuring the voltage across the battery. If it is ok, look at your grounds. Leaving the negative at the battery post and then measure the voltage at the clutch. If still low, go to the clutch relay. Measure the input. If low, trace backward to find the drop. If ok, measure the output of the relay. Find the problem before trying to modify around the problem.

[Cusser]

In diagnosing everything, I'm only getting about 11v to my compressor clutch. Could that be part of my clutch slipping problems? Where should I start looking to find the voltage draw?

1987 Chevy R30, 7.4l.

Is this measured with the engine running? Or with engine "off" ?

[jeepsj]

In diagnosing everything, I'm only getting about 11v to my compressor clutch. Could that be part of my clutch slipping problems? Where should I start looking to find the voltage draw?

1987 Chevy R30, 7.4l.

Is this measured with the engine running? Or with engine "off" ?

Engine running. Tested with my meter ground attached to battery.

[GM Tech]

clutches are programmed (GM anyway) to cut off at 10.5 system volts to save the engine from stalling- give it reserve battery power when losing voltage- as in a bad alternator. So 11 volts to the clutch won't cause your slipping issue- clutches don't slip until about 7 volts or so-- been there done those experiments with external power supply...but 11v is not as good as it should be-- should be near system voltage-- what is your system voltage running? at the battery with engine running?

[jeepsj]

Found some corroded connectors and cleaned it up and now have 13v at the compressor with engine running. Battery voltage is about 14v.