78 blower switch
Thread Starter
Heel & Toe
Joined: Apr 2013
Posts: 21
Likes: 1
From: Amherst Ohio
78 blower switch
blower motor only runs on high. when switch is in the low or medium fan speed position, nothing? changed out the switch, didn't help. any suggestions? doesn't matter what the slide switch is on (a/c, heat. vent) still only works on the high setting.
Le Mans Master
Joined: Aug 2006
Posts: 7,417
Likes: 1,554
From: mount holly NC
2025 c3 ('74-'82) of the Year Finalist - Unmodified
2019 C3 of Year Finalist (appearance mods)
Below the valve cover in the center of the picture is the resistor, make sure you have a good connection there.
Just to the right is the relay, check those wires too.
Just to the right is the relay, check those wires too.
Melting Slicks
Joined: Dec 2009
Posts: 3,222
Likes: 651
From: Thunder Bay
Get yourself a wiring diagram and start following the power. In addition to the switch, there is a resistor and a relay as shown in the picture above and a switch on the vent selector. It can be a problem at any of these connections, or a defective part.
Thread Starter
Heel & Toe
Joined: Apr 2013
Posts: 21
Likes: 1
From: Amherst Ohio
wanted to post a follow-up. I replaced the resistor even though it was not burned up, just slightly coroded; made not differrence! I replaced the blower motor switch in the dash; no difference. finally, just replaced the Fan relay switch under the hood, Wammo!! That was it!
Thanks again for the help! Now, on to bigger and better challenges.
Thanks again for the help! Now, on to bigger and better challenges.
