QuestionI'm having problems with the A/C control on my van. I know that this is not one of the years that you're really familiar with but I figured that since you know about electrical systems, maybe you could help me. The speed switch on the A/C dashboard controls has four speeds but the system only works on the fourth speed, otherwise it doesn't blow at all. Is there a problem with the dashboard controls, the blower or is there some relay that I need to check? I'd appreciate any help with this.
AnswerHi Fernando,
You are correct that I don't have a manual that covers the '01 and newer vans, but going from the design of the heater blower system on earlier year vans your problem is actually with a module called the resistor block that is mounted from the engine compartment on the firewall's far upper corner on the passenger side. It cuts the voltage in steps to reduce the blower speed and the resistor wiring will burn out and eliminate those lower speed settings.
Usually (on earlier year models) when it fails the fan operates only on high speed regardless of where you set the switch. But as I look at the late 90's van diagram I can see that if a resistor (the one attached to the tan/black input wire) in the block burns out, then only the high speed will operate on the fan.
It has an electrical plug with 5 wires. Remove the plug, then release the two screws and pull the resistor block out of the opening (the other side of the panel is actually in the air intake path which provides air to keep the resistors from burning out). You might electrically test its resistors/wiring and if necessary get a replacement from a pull it yourself wrecking yard or a new one from a dealer if it appears to be damaged.
That is my theory of why you have this problem.
If the resistor block seems to be o.k., then the switch on the A/C control itself is the problem. But verify that the block is o.k. before going any further.
Roland
