Discussion in 'How-To's' started by sturgilln, Jul 5, 2015.
The video kinda says it all:
The reason that resistor pack was completely dead is that there's a thermal fuse (3:51) wired in among the 4 coil resistors, and it was blown.
A thermal fuse can break either because there's too much current (like a regular fuse) or if the ambient temperature rises above what it's rated for, e.g., 200°F. So if your blower is set to high, but the blower motor is seized or badly clogged with debris, the thermal fuse will overheat and blow, theoretically preventing a fire down there. The resistor coils pass enough current to the blower to glow bright red if there's no airflow. In a pinch you could solder in a piece of paper clip to bypass the blown fuse if the 4 coils are all intact. The blower motor still has its own fuse in the fuse box.
BTW, that old resistor pack didn't look bad at all. They get really rusty and nasty looking after years of exposure to damp air when it rains, and usually one of the coils just breaks.
For the 2nd Gen 'scorts just replacing the resistor pack isn't enough.
My blower quit on me and I was thinking I was going to have to tear apart the dash and replace the blower fan.
Thanks to the YT video I found out that it was just the ground on the thermal fuse. Wiggled the ground and it worked perfectly. Sprayed some MAF cleaning solution on the spade connection on the thermal fuse and female connection on the ground wire along with taking a little steel wool wrapped around a stick and scrubbed both down to clean metal for a clean contact. Plugged it back in and it worked perfectly.
My guess is the thermal fuse is on it's way out so this will go on my list of preventative fixes. When a sale comes up online or at my local parts store I'll pickup a fuse and hold onto it until the stock one dies.
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