Do my blower switches work off fuses or relays?
The dash has two switches to blow heat or
ac to the back and front of my van. The
back switch is not working and the front
don't blow when switched to high.
Both, the system is fused and the blowers have resistor blocks for fan speeds and high blower relays, so if your fans work on all speeds but high the relay is usually the culprit. As for your rear unit not operating at all check for an auxiliary heater fan fuse first it could be under the hood separate of the main heat circuits. If it is not the fuse then you will have to start testing the auxiliary heat circuits to find out where you lost power.
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