Heater Control Switch
Thread Starter
Melting Slicks
Joined: Apr 2009
Posts: 2,564
Likes: 658
From: Virginia Beach VA
C2 of the Year Finalist - Modified 2020
C2 of Year Finalist (performance mods) 2019
Heater Control Switch
I have the Old Air system in my 66. Over the last 5 months, I have had 3 fuses for the blower blow. Saturday I lost both the heat and a/c. I have talked to Old Air and they recommended to check all wiring, especially the grounds. They also recommended to check out the heater control switch. The system uses the factory switch. I have no idea how old it is. I have been checking the vendors and have not found one yet. So, have any of you guys had a problem with this switch, where did you get a new one and are they made in the US. Any opinions on what this problem is are welcome. BTW, Old Air did not feel the blower is the problem. Thanks
Le Mans Master
Joined: Nov 2000
Posts: 7,246
Likes: 21
From: Going too fast over the hill. Iowa
What size fuse does oa run on? The factory ac used an inline 30amp under hood as well as a heater fuse in the fuse box. Did your car have an original factory ac setup before oa was installed? Max air fan on my 66 was supported by the ac relay under the hood, not the fan switch.
Thread Starter
Melting Slicks
Joined: Apr 2009
Posts: 2,564
Likes: 658
From: Virginia Beach VA
C2 of the Year Finalist - Modified 2020
C2 of Year Finalist (performance mods) 2019
The car did not have air prior to the oa being added. The blower is on a 15 amp and the ac is on a 30 which is a connected to a battery male connector next to the fuse panel. Zip has a switch if I need one. I am taking the car to a shop this afternoon. Thanks for the reply.
Le Mans Master
Joined: Nov 2000
Posts: 7,246
Likes: 21
From: Going too fast over the hill. Iowa
The blower on a factory car works off a 10amp fuse. I have no idea how oa powers their blower, but if they don't use a relay for max air, the wire gauge from the switch to the fuse panel may not be sufficient to keep the fuse TEMPERATURE down, which can cause fuse problems. Rust or corrosion at the fuse holder can also cause problems. Make sure that your fan motor has at least a 14gauge ground line. Check the voltage at the fuse to be sure it's at least 12volts. Voltage drops caused by corrosion in old cars tend to add up.
Le Mans Master
Joined: Oct 2000
Posts: 8,897
Likes: 1,357
From: Santa Ana CA
It is also possible that you are drawing excessive current because the motor is being "stalled" by excessive friction from corrosion, lack of lubrication, something rubbing, etc.
When a motor is "held" or "stalled," the current goes way up.
When a motor is "held" or "stalled," the current goes way up.
Le Mans Master
Joined: Nov 2000
Posts: 7,246
Likes: 21
From: Going too fast over the hill. Iowa
I thought of suggesting a mouse may have built a nest in the blower cage (happened to me twice), but I figured oa gave him a new motor and housing. Did they?
