Is there 12v supplied to the fan from the HVAC c.u. when the fan runs up and down like that?

 

Go behind the glovebox and next to the fan motor housing is a module with a six pin harness connector. This is the fan control box or regulator.

Mr. Tweaked hit this nail on its head a few posts back. Our OPs excellent transcription of the CC head numbers show a problem on data channel 18 & 19

Possible cause for the engine on/off failure differences is probably the supplied voltage going from 12 to ~14.

 

Ok, thxs

But which of the pins in the connector should have 12v.

Also when the scale is showing the fan going up and down in its speed,the fanactually is doing nothing, in other words it don't run its stationary when the engine is running, but if I turn the ignition from fresh the fan will run and can be controlled. It only when the engine is actually started, is when the problem starts.

Thxs again