1996 Damon Intruder AC Question

[dad4papa2]

My heater and AC Blower motor has quit working on my 1996 Ford F53 Chassis. I had lost the high speed some time ago but was ok with the lower levels as they were sufficient for my needs. However I went out 2 days ago and warmed up the MH and the fan would not work at all.

Here's what I have checked so far.
1. Checked the fuses under the hood in the power box. All Good.
2. I unhooked the 2 wires from the fan motor and made jumper wires to hook up to it and ran them out to the battery direct. The motor took of in high and I let it run for just a couple seconds. So this should out rule the motor being bad.

So what do I check now??? I see that there is a resistor supposed to be on it but I don't see one yet. I will look further into that today to see if I can find it.

Does anyone know where it might be located at??

Any other input is welcome!

Thanks Much Dad

[dad4papa2]

I went out and I need to correct my earlier post. I can feel and hear that relay click going back to high also. So I can feel the vibration and hear the click going from high to med speed and the same goin back. It started raining so I had to quit! I unhook it as soon as I can and see what it dies.
Thanks again for your help!

[dad4papa2]

I haven’t tried to remove it yet but I will go try it. I can move the speed control switch from high to medium and back to high. I only feel or hear the click when moving from high to the lower setting. When I move it back to high I hear or feel nothing. I will go try to unhook it and see what it does!

Thanks for all your help Dennis

[enblethen]

It could be a bad relay
What happens when you remove the relay, does the circuit breaker trip?

[dad4papa2]

This relay is under the hood just above the windshield washer bottle on the firewall.
Thanks much Dennis

[dad4papa2]

I am still trying to get to the confirm stage of the common wire and the hot wire but I needed to ask this also.

When I turn on my key and put the blower motor speed control to high position and then move it down to the next lower setting I get this clicking sound. I have finally tracked it down and I am adding a picture of it.

I laid my hand on it and my wife moved the fan speed lever and I could feel it vibrate and click as she lowered the speed to one lower
speed.
Should this be doing that? Is it tripping this breaker to shut off power to the fan. If so I know I need to find the issue that is tripping this relay.

Thanks Dennis

[enblethen]

Verify which is common (motor) terminal on resistor assembly
Verify 12 volt input terminal

[dad4papa2]

Here is some new information. It has me baffled to no end.
I removes the blower motor. Hooked up to my lawn mower battery. It took off and runs fine.
While it was out I used my multi-meter and on the two terminals I had unhooked I probed the two wires.
When I set the blower to high fan I get a 11.9 volt reading.
When I go to any of the lower setting I get no readings at all.
So I reinstalled the motor thinking I could switch blower motor to high as I was sending 11.9 volts on the high side but now I get no motor running at all on any speed.

Any suggestions is appreciated as what this could be??

Thanks Much
Denni

[dad4papa2]

Thanks much. I am still hearing the little click when I have the air on and the cold air slide moved to the far cold side.

This is the same no matter if it is in the cool mode or the heat mode. The fan blower motor will just not run in any speed.

The link you sent me suggests to check the relay on the blower in the power box I believe. My book for the ford chassis shows a blower mother relay under the hood is #4. This is the one I thought was clicking but it isn't doing anything when I listen to it or feel it while moving the blower switch up and down.

Here is a part of the link that you sent me that showed how to test for different problems that may be an issue with the blower.

Identifying the fault
When trying to diagnose a blower fan motor, the following steps should be followed:

If a car’s blower motor doesn’t work at all, there are several components to be checked in the system:

Check the fuse for power on both ends using a multimeter. If there is power on one end of the blower fan fuse but not the other, then the fuse needs to be replaced.
Check the fan relay, if the car is equipped with one. Such relays can be tested by placing a finger on them and switching the fan’s control on and off. Clicking from the relay is an indication that the relay is almost certainly working correctly.
Check the fan itself for power presence by turning on the fan control and checking the fan itself for +12V at its terminals. To do this, switch your multimeter to voltage measuring mode and verify that the voltage difference between the fan’s terminals is 12V. If there is no power present at the fan, suspect a wiring fault. In this case, it’s best to take the car to a certified auto electrician. If power is present on the fan’s terminals and the fan is not working, the blower fan is defective.

I have checked the fuse. It is not burnt out.

I found the relay that my book calls the Blower motor Relay and by moving the fan to off and on feel nothing or hear nothing. I suspect this might be an issue.

I also on the motor itself have a black wire and a red wire that appears to be the power and ground to the fan blower. I tested the volt going to those two wires by using my volt meter and there is nothing in volts from the Low- med-med high position but when I move to the high position I get a 4.23 volt for a split second and then it goes to zero. Again for some reason I suspect the relay but not sure.

Also i am searching for a broken wire somewhere but not findind any.

So with all of this any input would certainly be appreciated.

Thanks so much for all your help.
Dennis

[enblethen]

Only clicking you should hear is the AC relay. The fan does not have a relay.
Remember that the AC on majority will come on in defrost mode as well as AC mode.

[dad4papa2]

I might add that on the top photo I only hear the clicking sound when I move it from high speed down one slot to medium speed.
Dad

[dad4papa2]

Ok here is a phot0 of my switches. I think I am narrowing the issue down but still need some help!


What do I do now! I put the new resistor in and same issue!! No fan speeds at all.
Dad

[dad4papa2]

Thanks Much for the link. I found mine got it out and tested it. I am pretty sure it is bad. Got one ordered and hope to get it next week. Thanks again for the info. Once I get it in I will post my results!
Thanks Dennis

[enblethen]

The assemblies are open resistors.
If there is a diode, reverse your leads and you should get continuity. Diodes pass voltage in one direction and not the other.
There should be no ground.
The main terminal should be coming from the fan switch.

Blower resistor

[dad4papa2]

Sorry I don't have any continuity through the diode!
Dennis