Miller 225D Machine run/idle Issue

[Randy L]

I have an early 2000s model Miller Bobcat 225D that keeps tripping CB8 (10 amp circuit breaker) when running in fast mode. I already changed the PC1 Idle Board module and still having the same issue. Also, when in run/idle mode and after reset of circuit breaker motor will not increase to fast when striking arc. Only way to get motor to increase to fast mode is to change selector switch from run/idle to run. Motor will run in fast mode for a few seconds and then trips CB8. Any suggestions??

[duaneb55]

You may have a defective (shorted) throttle solenoid.

Unplug it and check the resistance across its leads. Spec is less than 1ohm extended, 10-12ohms retracted (plunger bottomed).

[duaneb55]

You also need to make sure the throttle solenoid plunger bottoms out at high idle (weld) speed.