Heater fan not working?

Have you checked fuses? Is there power to the switch? check out this guide to help us

https://www.2carpros.com/articles/blower-fan-motor-works-on-high-speed-only

Please run down this guide and report back.

Actually, I was refering to the switch on the dash. See if there is power to it and out when you turn the switch on.

Let me know what you find.

The air flow vents are actuated by engine vacuum, so they will still work if there is no power. As far as the switch itself, there may be power to it but not out. Have you checked the relay in the power distribution box under the hood?

As far as the switch, the bezel that covers or trims the radio and heater control comes off. Under it are a couple bolts that hold the unit in place. If I recall, the bezel is actually mounted with non other than valcro. Be careful removing it to make sure that is correct.
Let me know what you find.
Joe

Actually, if you check the other relays, you'll find ones with the same part numbers. Just switch them to see if it is bad. If it is, then get one.

Let me know what you find.

Joe

Replace the blower resistor. You might have burned out the blower motor also while running in high. The resistor is under the hood on the passenger side screwed into the A/C plastic cowling. It has connector and two screws that holds it in. check this guide which shows how to test it

https://www.2carpros.com/articles/blower-fan-motor-works-on-high-speed-only

Please run down this guide and report back.

I have converted hundreds of Fords to 134A. Some work great without any alterations except a clean charge.

If one is acting like yours I suspect you will need to change the orfice tube and the dryer. The replacement orfice tube must be for 134.

I use ester oil in a Ford, it seems to wrok better. Remember the 134 charge is about 23% less refrigerant than R-12. You must charge by watching the gauges on both high and low sides. It is very easy to overcharge and the cooling will be reduced. Even a couple of ozs will reduce cooling.

If you car is loosing refrigerant and it is on the suction side (low pressure) it will suck in outside air through the leak and your cooling will be greatly reduced.

Fix the leak and stay away from the $7.00 can. It is mostly propane and dangerous to uses in addition it will corrode your system. There are no cheap solution to referigerant as R-134A is about $7.50 a can but it goes up as gasoline goes up.

Good luck

Hi:
Replace the blower motor resister. It's the most common problem resulting in the blower motor not to work.

Joe

First check if you have 12 volts on the dark green wire to the fan motor. If you do not, check for it on terminal 30 of the relay.

These diagrams are for the heater with AC. If you have just the heater system, I'll prepare different diagrams for you.

If you have 12 volts on the dark green wire, check also on the gray wire. That has to be done with the connector plugged in. The weakest link in the chain is the fan speed switch. It's common to find the connector terminals burned and melted, especially if the fan is used on the highest speed often. This is a good suspect if you have 12 volts on the gray wire.

Hi,

In addition to checking fuses, have you confirmed there is power to them and the relays?

I attached a pic below which is the wiring schematic for the blower motor and HVAC system. Take a look at it and see if you touched on the relays, resister, and all fuses related. Also, check to make sure there is power at the fuse locations.

https://www.2carpros.com/articles/how-to-check-a-car-fuse

Let me know.

Joe

Hi:
I going to take a wild guess and say you mixed up the plugs (wiring harness). Recheck and let me know what you find.

Joe