A/C fan switch on control panel

MOORELYNN

MEMBER
1997 FORD E-SERIES VAN
5.4L
V8
2WD
AUTOMATIC
1,000,000 MILES

The blower motor fuse keep blowing out. Long as I'm driving the fuse will not blow out, but when I park and leave the vehicle idle in park for about 5 minutes with the air condition on the fuse will blow out. The rear unit also. Replaced the fuse again does the same thing again. Replaced the blower motor, resistor had the wires checked no broken wires. Replaced the resistor twice. Now the blower motor switch only works on high speed, some times on low or medium. Checked the connection behind the blower motor switch no burnt spots all good. Oh replaced the blower motor switch also still only works on high speed.

1 Reply

BMDOUBLE

MECHANIC
1,139 POSTS

I could give you tons of circuit tests, but I will tell you what I would do. Get yourself a low amperage clamp on tester and clamp onto the blower motor wires and turn the blower motor on at different speeds and take note of the amperage in relation to the fuse that is blowing. The readings you get will be self explanatory. I read that you checked the connections for burn spots, but what I've found is that after a blower motor issue the pins at the connector will splay out or be a little loose. You can do a pin drag test by putting a similar sized spade pin and push it into the female connector, it should have a slight drag to it. If you can hold the connector upside down and the pin falls out, no good! These connectors are usually available as a pigtail that can be spliced in. Just a thought, hope this helps! I bought one of those clamp on meters for $20.00 from amazon FYI.