Heating Issue

[Richard C]

The rear heat on my 2000 Windstar SE is not working. The blower is working fine but only cold air comes out of the vents. The heater for the front of the van is working fine. It is too cold not to have heat in the back for my kids.

At the same time, the power locks stopped working except for the driver's door.

Anyone have any suggestions before I take it in to the dealer as a last resort? Thanks in advance.

[12Ounce]

The rear (and the front) temperatures are affected by the position of a "blend door". You might remove the left-rear plastic quarter trim panel to have a look. You will see both the "blend door" and the "mode (up-down) doors" ... and their actuators.

Observe movement while adjusting temperature controller. You may find you have a defunct actuator.

As an interem (sp?) fix, you might disconnect the elect connector and prop the blend door in a heating position.

(I would suggest you also disconnect the ac compressor, but you could not imagine the responses this suggestion brings about!)

[DRW1000]

Originally Posted by 12Ounce

(I would suggest you also disconnect the ac compressor, but you could not imagine the responses this suggestion brings about!)

I had to laugh when I read this - I read some of the responses to your suggestion in a different thread. I too remember when AC was a luxury and my cars never had it. In fact my Windstar is my first car with AC. Although I can appreciate the dry air idea for defogging It doesn't help much when frozen. I don't recall ever having a problem that the heater only defrosters couldn't handle.

[Richard C]

It looks like Fuse #8 controls the power door lock acutators (not the driver's door, however) and the blend door for the rear heat/ac. The fuse was blown so I replaced it but something keeps blowing the fuse. A short circuit somewhere?

I know eletrical gremlins can be a pain in the rear so does anyone have any suggestions? Thanks.

[Selectron]

I'm not familiar with your vehicle so I can't give you any specific help, but here is how I would go about locating the short-circuit. Do you have access to a multimeter? I'll assume that you do. Firstly, remove the dead fuse and then, with the meter on the DC voltage range, connect the black lead to ground and with the red lead, probe both sides of the fuse socket. One side will read 12V and the other side will read 0V - it is the 0V side of the circuit that you are interested in, because that is where the short is.

Switch now to the resistance (ohms) range and measure the resistance between the dead side of the fuse socket, and ground. You will expect to see a very low resistance value, probably zero ohms if it is blowing fuses. Next step would be to gain access to the electrical connectors for each of the door lock actuators where possible, and the connector for the blend door actuator, and disconnect them one at a time, measuring the resistance from the dead side of the fuse to ground again as you disconnect each item. When the resistance suddenly climbs back above zero, that would indicate that the item which you just disconnected is the one that contains the short.

It would then be a case of investigating that circuit, looking first for obvious things such as chafed wiring, especially at flexible conduits such as would be fitted to the doors, for the power locks. It's a simple procedure on paper when looking at a wiring diagram but of course in practice it's a more daunting proposition when all the wiring is tucked away behind panelling.

[12Ounce]

Good sleuthing thus far!

I've just loaned out my elect diagram book. When it comes back (in a few days), I'll see if I find any clues.