In my 1988 E-350 (460 engine), the heater blower stopped working, checked all fuses, when pulling the heater fuse and reinserting I hear the relay clicking, checked all connections (also had the control unit out), moving the heat adjusters I hear the vacuum lines, but no blower. Is it the resistor? Any other ideas?

It's too cold in Pennsylvania to drive wothout it.

 

I'd be interested in knowing myself. Just tried to help resolve the same failure on my Uncle's '90 E-250. One of the aftermarket manuals mentioned a blower motor relay, but I could not find it. We heard what we thought was a relay clicking when we moved the air control switch which includes the fan on/off. However it was just the AC clutch. We replaced both dash control switches, on/off/vacuum lines & lo-med-hi speed w/o success. I hot wired the fan to confirm it ran perfectly. I checked the resistors in the plenum right behind the blower motor & all was good. Was unable to locate G202 ground behind dash & read that there's a fusible link in the wiring to blower. Ended up frustrated, mystified & out of time to fix what I'd thought would be an easy job. Did a quick & dirty mod so that he'd have heat when he returned north & set up an under hood hook up so he could plug the blower directly to the battery.

 

I just fixed my blower on my 88 e150 quigley it was the relay in front of the battery on passenger side mr-27 at autozone or advance it is listed as ac relay or aux heater relay they corrode easy because of location

 

On the '90 E-250 I found the voltage regulator immediately in front of the battery. There was a box behind, above & to the right of the battery that appeared to house 2 relays, but none of the wire color patterns, or even gauges, matched the wires to either the blower or the resistors. This vehicle appeared no to have a rear aux heater.

 

On my 88 E150 I removed the battery and the relay was mounted on the radiator support in front of the battery. 3 wires yellowand red-yellow-and one was orange. MR- 27 at autozone or advance