MANOFTHETIRE

Hi,
I'm back with another problem, this time it is with the rear a/c blower, it quit blowing, the relays ohm out good and the blower motor will run when power is applied to the connector. But when everything is together it will not blow on any speed, also cannot find a resister in the rear duct work. Any help will be great fully appreciated
THANKS

mp2140

The rear heater / A/C blower motor has 2 circuits. One delivers power to the blower motor itself and the other is for the controls. There's 2 fuses for this system too. One is a 30 amp fuse located in the fuse box under the hood, that one is for the blower motor. The second is for the control circuit and it's a 10 amp fuse located in the fuse box under the dash on the left side near the hood release. The resistor for this unit is located to the lower left of the round grill where the air intake is for the rear blower. There's 2 screws diagonally from each other that hold the resistor module in place.

Next step would be to get a volt meter or test light so you can see where you do and don't have voltage. The fan speed switch provides a ground to the -negative side of each relay coil. When the ignition key is switched on you should have voltage from ground (the frame of the van) to the +positive side of each relay coil. The circuit that feeds into the contact of each relay should have voltage on it all of the time wether or not the key is switched on or off. When each relay is activated by the control up front, the appropriate relay should activate and deliver power to either the resistor module (for speeds 1 & 2) or directly to the motor (speed 3).

Since your saying that there's no power making it to the blower motor, but the motor runs when connected to a power source. I'd say that either your control circuit isn't getting power before it makes it back to the relays or the control switch isn't delivering the ground to activate each relay. Or there's no power on the blower circuit and it's not delivering voltage to the relay contacts that then would deliver voltage to the resistor module and the motor.

I hope that helps. Let us know how it goes.

MANOFTHETIRE

After rereading my post, there was some information that I ommited. Such as the van is a MARK 3 conversion van and under the hood is a sticker that let's you know that it is an Atwood a/c unit
Sorry for not including this info before

I ll do the checks on the power again. It will be the same procedure as described for this unit but I can't find the resistor anywhere at the blower housing or duct work
Thanks for any information on this

mp2140

I'm not as familiar with the conversion vans as I am with the stock passenger vans. I hope you find out whats going on with your A/C. Let us know what you find. Good luck.

MANOFTHETIRE

Hi everyone, got it fixed, the fan motor was bad. Bought a new one and put it in and everything worked fine
Thanks for your help