The front fan on my 2003 T&C doesn't work most of the time. I have replaced the resistor behind the glovebox.

This van has dual zones up front.

The front fan doesn't work most of the time and it's not stuck on high.

Sometimes it works fine though and all speeds work... WHEN it works.

Blower works when 12v is applied to it every time.

What could this be?

Replace the front blower relay in the underhood fuse box (IPM) or just swap it with another identicle relay on the panel. Inspect the connection at the blower motor for damage or corrosion. Do you have and know how to use a multimeter?

I have swapped the relay for the relay for the back blower... no change.

Back still works, front doesn't work 90% of the time.

I have inspected the wiring and connections to the blower and resister, all appear to be in good condition, no signs of corrosion or damage.

I have a multimeter... but not proficient with it , but trying to learn to use it more as a tool. I know how to check continuity (as long as I'm able to trace a wires location) and voltage.

had similar problem with my 97 caravan-replaced resistor, relay, then went to replace blower motor.......1/2 way through I
noticed electrical tape on the blower wiring indicated it had been replaced before......took tape off and found pigtrail connection was corroded green. cleaned it up now works 100%. :) just time for the cold weather. good luck!! Mike
The front fan on my 2003 T&C doesn't work most of the time. I have replaced the resistor behind the glovebox.

This van has dual zones up front.

The front fan doesn't work most of the time and it's not stuck on high.

Sometimes it works fine though and all speeds work... WHEN it works.

Blower works when 12v is applied to it every time.

What could this be?

You have to change the blower motor, I had that problem on another car and was the blower motor.