Rear Heater Fan

I never tried running my rear heater fan after picking up the van last October since I almost immediately bypassed the rear heater core due to the hard lines being rotten.  Those hard lines got replaced in December, and a part of that job was me removing the two trim panels on the driver's side.

Today I reinstalled the forward trim panel, reconnecting all the controls for the rear heater. I cranked up the van and I get a light on the rear heater buttons, both on the dash and on the trim panel, but the rear fan doesn't blow air on any of the Lo/Hi/Auto settings. I let the van warm up in case the fan isn't supposed to kick on until the coolant warms up, but no joy.

I checked the fuse panel under the steering column, and the relay panel under the center of the dash, but there wasn't anything that specifically called out the rear heater fan. There was a relay titled Rear Heater, and I swapped the defroster relay (same part no.) into its receptacle to no effect.

Does anyone have advice on how to troubleshoot why the fan might not be running? Thanks!

I would take a multimeter and start measuring.

The fan should run all the time it's on, there's no thermostat.

Did you reinstall the panel that fits over the heater? If so check you connected it all back as there is a number of plugs for it. I found the cable to operate the water valve the most awkward bit, never did figure how to disconnect it properly.

False alarm, after taking the panel off to check that I had securely plugged all of the heater control wiring connectors back in I noticed that my mechanic had actually unplugged the connector that powers the fan. Glad it was something so simple!

So as not to make this thread completely worthless, my method for disconnecting the valve cable was to pinch the barbs at the end of the arrow-shaped connector and work the loop over them. it is a delicate, fussy job for sure.