I have a 95 pontiac transport with front and rear ac/heat i recently replaced both blowere motors but they still work intermitenly the start and run but then shut off and keep coming back on and repeating this cycle i think there is a thermal fuse that keeps blowing and restting but i can't find it any ideas?

front blower has a problem rear does not

Sounds like high blower relay is bad

a blown fuse or bad switch, bad blower motor

I had a 2003 caddy dts same issue the blower motor has probably gone bad u can order them online. What u can also try is kicking under the passenger side glove box area that's where the blower is located sometimes they get stuck. Try kicking or tapping under there and see if it pops on. I did this with my car

Change the. Blower motor resistor. $25 part near the blower. Chevy suvs are famous for bad blower resistors

steve, have you tried checking the blower motor resistor in the blower motor itself to see if its burnt?

A mechanic would unplug the blower motor and check the circuit for shorts to ground.

The most common problem would be a bad blower at which you can test for power at the motor connector with a testlight, the other most common problem is the resisitor ,theres one for the front blower and one for the rear blower, you may have a bad resisitor for the rear blower this resistor is located next to blower.theres also arelay in the fuse/relay box next to the battery under the hood,the best thing is to start testing for ower at the switch and work your way to resistor, i think you will find a bad resistor to rear blower motor.heres a complete wiring diagram of the whole front and rear heat and ac unit, everything is labeled good luck.

From your description, it sounds like your fan is the problem? I'm not intimately familiar with the pontiac vans but you pretty much need to track down the heater fan motor and the wiring between it and the switch. Check these wires for a fault and/or replace the wiring or the switch or the motor if need be. Because it's an intermittent fault, I think you probably just have a poor connection.

Check all your fuses just in case.

Good luck!
Sherwin

chk the fan speed resistors mounted in the fan housing. You should be able to see the wires going into the box with 2 screws holding the resistors in place. Good Luck.