Jump to content

Hydraulic fan at full speed

Recommended Posts

Hi guys and happy New Year.

 I'm slowly but surely fixing things on this old coach. I've moved on to the hydraulic fan now and I'm scratching my head a little. Maybe someone can point me in the right direction with this one. Okay.....2001 sig Exec 500 ISM hydraulic fan. Runs at full speed all the time. I went to check flow at the wax valve yesterday and noticed a small electrical coil on a valve before the wax valve itself ....that I've overlooked before.  I took the coil off and boom, the fan goes to idle. I looked at my schematics and I can't find the wiring for this coil. I traced it back to a relay in the rear run box on the left. As far as I can tell it gets +power from battery and the ground is the "excite" signal from either the thermostat sensor and or, the intake sensor? I unplugged both sensors and still have full speed fan. What am I missing?

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • Create New...