Console blower switch

[Raymond W.]

What's up with the operation of this switch? There are five detente positions on my ac/heat console blower switch (Off and 4 fan speeds). When in the off position, the fan runs at what appears to be the first low speed. When moved to the next position (which should be the first low speed position) there is no change from the low fan speed. When moved to the next two positions, the fan speed increases incrementally as it should. Then when it's moved to the fifth/Hi position, the fan shuts off. I rarely use the ac or the heat so I don't have much of an operating or inopperable history to share. However, I do recall this happening once before (I only noticed the lack of the Hi fan speed and thought I needed a new switch. I never investigated it any further because shortly thereafter, the operation of the Hi fan speed returned. Now it's not working again? Before I start jumping into the console, replacing switches, resisters, relays, etc, does anyone have any thoughts or insights from past experiences to share. I'm also not very comfortable when it comes to electrical testing. Thanks, Ray

[Jim T.]

Re: Console blower switch

What's up with the operation of this switch? There are five detente positions on my ac/heat console blower switch (Off and 4 fan speeds). When in the off position, the fan runs at what appears to be the first low speed. When moved to the next position (which should be the first low speed position) there is no change from the low fan speed. When moved to the next two positions, the fan speed increases incrementally as it should. Then when it's moved to the fifth/Hi position, the fan shuts off. I rarely use the ac or the heat so I don't have much of an operating or inopperable history to share. However, I do recall this happening once before (I only noticed the lack of the Hi fan speed and thought I needed a new switch. I never investigated it any further because shortly thereafter, the operation of the Hi fan speed returned. Now it's not working again? Before I start jumping into the console, replacing switches, resisters, relays, etc, does anyone have any thoughts or insights from past experiences to share. I'm also not very comfortable when it comes to electrical testing. Thanks, Ray

Ray the reason your switch does not operate the fan blower in the highest position could be a blown or even missing inline fuse. The high speed blower fuse is a 30 series if I remember correctly. In my 70 it is located near the front of the master cylinder. You should see a heavy guage red wire coming from the fender mounted relay to one end of the inline fuse holder. The other end of the inline fuse holder uses a orange colored heavy guage wire. This is the colors my 70 uses.

The fan blower switch turned to the left and will operate automatically on low whenever a selection is made that will use the air conditioner compressor for cooling and the bi-level positon. It is designed to have the fan motor blowing air through the evaporator when the compressor is circulating R12.

[Raymond W.]

Re: Console blower switch

Jim, thanks...I got it working! The fuse wasn't blown, but it was stuck in the fuse holder which made me think that a good connection wasn't being made. After cleaning and freeing it up, that's not what it was. I then pulled the connections to the Blower Resistor, AC Relay and AC/Heater Blower Ground, cleaned up all the terminals and reinstalled. The fan now works when in the Hi detante position. Sometimes a fix like this is relatively easy, other times it a hunt. I had pulled my Chassis Service Manual after I posted my question and reviewed the troubleshooting pages on this item. That, combined with the TDB's insights has always helped me to resolve most every fix I've encountered.