1999 Cutter, dash AC/heat issues

[Moorchen]

After a recent trip my dash AC/heat stopped working altogether (including fan for airducts in front). Any one with similar problem in the past and what was solution?
Thanks! Moorchen

[masseyfarm]

Could just be a loose plug on the back of the heater control? or bad ground on the fan motor? I assume you have checked the fuse?

Dave

Originally Posted by Moorchen

After a recent trip my dash AC/heat stopped working altogether (including fan for airducts in front). Any one with similar problem in the past and what was solution?
Thanks! Moorchen

[Moorchen]

thanks Dave; yes, I have checked the fuses (as far as I can find them, both in the front as well as next to the driver's seat), and I have found some problems (mostly with corrosion) which I repaired as I was playing "detective". However, I have yet to find the problem. I can 'bridge" from a hot source to the fan control, and the fan will run. So it is not a grounding problem. I am just totally "stumped" that after a 2 week trip when constantly using the AC (it was hot in early October in Florida, GA, SC, NC, and VA) and using the dash heat when approaching central PA in the evening, that the system worked perfectly well. The very next day I drove the unit to my house to begin winterizing. On the short trip (1.5 miles) nothing on the dash AC/Heat would work.
In going over the electrical diagram that I found in the owner's manual (too much reduction to read most labels), I find that there must be some interesting in-line fuses. But where is the big question? I found two when opening the front access for the generator. There on the firewall were several fuses. They work. So, where do I go from here?

[Vycan]

Just clarifying here... Your AC/heater stopped working altogether is pretty vague.

Do you mean you stopped getting air out of your ducts at any setting? I ask to clarify because if you can get the blower to spin by jumping it, that means your fan blower resistor is either burned (unlikely) or corroded (likely) they are untreated metal coils and tend to rust. I remove them and write down the part number, then I set the resistor in rust remover in a small tupperware (just barely bigger than the blower resistor) for an hour. After time is up I take them out and inspect them for breaks. If no breaks I clean, dry and reinstall, and viola.... it works! If not, I get the replacement part and install it.

[masseyfarm]

On my CLIPPER, the high speed on blower runs through a relay located on outside of the front bulkhead. That might be in your Genet compartment on the Cutter?
The heater resistor that runs the lower speeds, is also located there, higher up on the bulkhead.
The heater resistor is a common Ford part. You may have to trim the board slightly to fit.
Take your old one to NAPA and ask for same.
By looking at the resistor you will have a good idea if it is corroded or burnt.
But, you should have either the high speed OR the low speeds.
Have you checked the power at the dash control?
Dave


]

[Vycan]

Thinking on your post Masseyfarm... You bring up a good point about the relay. If there's a relay in the system that went bed, wouldn't it kill all speeds of fan? The relay provides power to the circuit, and the resistors allow adjustment to the power for the different speeds. So thinking through this the resistor would no longer seem to be the culprit, but the relay. I would check the relay plug with a multimeter set to 20VDC to verify the circuit is receiving power when HVAC is turned on. Then I would replace the relay and get a helper to turn the HVAC system on and off to listen for the relay click. If too much noise in the area I would do the same, but put my fingers on it to feel for the click.

An easier fix, take a system that you know works and uses a relay, unplug your suspected bad blower relay and set it down so you cannot confuse it with another one, and don't lose it. Then take the relay from a known working system, unplug it, and plug it into the HVAC relay position. Now try the fans... if they work, bad relay, if not, something else.

[masseyfarm]

OK, I read this again, and the problem is power to the heater control switch and beyond. You say you have jumped power to that switch, and the heater works.
On you fuse panel, probably on the front bulkhead of the CUTTER? on in the dash? or the newer ones had a left front compartment for the electrical?
you should have your normal tube/barrel fuses.
Just because they test good when touched with a DVM, does not always mean good contact is there. Try removing the fuse, and if no corrosion found, clean and reinstall. Check the wire connection for signs of burning or corrosion.
The heater fan draws plenty of juice on high speed, (especially if no relay was in the circuit) and a good clean connection is needed.
The relay would always be located after the control switch to reduce power demand on that switch.
If your fan works when you jump power to the switch plug, then make sure the plug itself, of the switch is not burnt.

Dave

Originally Posted by Moorchen

thanks Dave; yes, I have checked the fuses (as far as I can find them, both in the front as well as next to the driver's seat), and I have found some problems (mostly with corrosion) which I repaired as I was playing "detective". However, I have yet to find the problem. I can 'bridge" from a hot source to the fan control, and the fan will run. So it is not a grounding problem. I am just totally "stumped" that after a 2 week trip when constantly using the AC (it was hot in early October in Florida, GA, SC, NC, and VA) and using the dash heat when approaching central PA in the evening, that the system worked perfectly well. The very next day I drove the unit to my house to begin winterizing. On the short trip (1.5 miles) nothing on the dash AC/Heat would work.
In going over the electrical diagram that I found in the owner's manual (too much reduction to read most labels), I find that there must be some interesting in-line fuses. But where is the big question? I found two when opening the front access for the generator. There on the firewall were several fuses. They work. So, where do I go from here?