Quote:
Originally Posted by DRACO A5OG
+1 on the Bi-Metalic Switch, check the contact to insure there is no corrosion there. Not sure how to check if the switch is bad but that switch does control the speed. It sits right next to the water drain off and if you live in a rainy climate, it could get wet.
I've sealed that area except for the drain for extra measure.
After that I would check the relay in the smuggler's box. My relay was buzzing like crazy and tripping my fuse. I removed and tapped on it. apparently it was getting stuck in there. I ordered a new relay but the buzzing and fuse tripping did not re-surface. All COOL Now  |
The low/med speed controls consist of two fairly high power consumption nichrome wire wound resistors mounted within the cabin air return duct to the evaporator fan inlet/suction side.
These resistors can/will get VERY hot if there is not sufficient airflow over them. Hot enough to start a fire so the bi-metallic switch contacts are used to open the low/med speed circuit if the resistors begin to overheat.
The first thing to do is make sure you have a FREE/open/unblocked, airflow path throughout the A/C airflow ducting. A partially clogged evaporator itself is not out of the question as is the possibility of extreme dirt deposits on the squirrel cage blower fan vane surfaces.
Back in my USAF days ('57-60) we always carried small files to clean/clear/burnish relay contacts such as these. Use a little emery cloth to burnish the bi-metallic switch contacts and all will be well again.