Under dash on passenger side.
Without knowing the symptoms, I can't pinpoint an answer. However, the most common problem with heater blowers are the resister stacks. When they fail, the fan only works on high speed and does not work on the lower speeds. It is strictly a dealer part around $30. Easy to replace.
It's in the heater core housing.
Lincoln Borglum died in 1986.
can I buypass the rear heater valve and run two heater 1986 gmc van
check the fuse or the ground on the heater
Loosen the dash and pull out the complete heater box after you have disconnected the heater hose from the firewall...........
Talk2DIY Automotive - 1986 Tires and Changing Heater Core was released on: USA: 14 August 2004
you will find it in the heater box, also where the blower is. it is easy to remove.
Not practical to try to fix a heater core. Replace it with a new one.
If that made sense i'd answer it
osmobile delta88
Is the fuse blown? Are all the electrical wires to the switch connected? A new unit from an auto wrecker shouldn't be expensive.