Mustang Owners Club Australia Forum

Technical & General Discussion Area => Tech Torque Pre 1973 => Topic started by: thruster on November 03, 2011, 07:45:41 pm

Title: 66 Heater switch
Post by: thruster on November 03, 2011, 07:45:41 pm

Hi all,
 I have just been attacking the switch for the 3 speed fan and have found that the problem was  bad grounding via the chrome housing that the switch is screwed to, the motor would not work and after some research I found that the control panel is the common ground so after removing the switch cleanining it up and soldering a new earth wire ( I didnt trust the housing) I put it all back together and the motor now operates yet I cant hear it working on anything but the high setting so would that be the red resistor on the box with the 3 prong harness and single yellow from the motor or the switch . I am hoping the resistor as its a much easier and cheaper fix,any feed back would be great guys.

 Regards john.

Title: 66 Heater switch
Post by: griff on November 03, 2011, 07:56:21 pm

that should be it john, as its the only means of varying the fan speed.
throw a multimeter over the blower motor resistor terminals and see if it varies, obviously low speed will have the highest ohm reading and progressively lower to 2nd then 3rd. also check your switch to see its not shorting across its terminals
hope this helps mate

Title: 66 Heater switch
Post by: thruster on November 03, 2011, 08:37:32 pm

Thanks mate I will do that after work tomorrow,I wasn't sure how to test it,nbow I just have to work out how hard they are to change as theres no screws just 2 rivetts :banghead:

  Regards John.

Title: 66 Heater switch
Post by: pbapam on November 04, 2011, 09:35:41 am

Hey John,

The resistor is pretty easy to replace. It is held to the heater casing via two clips that pop out easily and can be re-used. Easiest way to test it is to bypass it and see if you fan turns on continuously.
The resistor itself is not expensive. I think I paid under $40 for it a couple of years ago when I reconditioned my heater.

Sent you a u2u

Title: 66 Heater switch
Post by: thruster on November 04, 2011, 12:33:09 pm

   Hi pbapam,

  thanks for the advice and the U2U info it was very usefull.

  Cheers John.

Title: 66 Heater switch
Post by: thruster on November 04, 2011, 06:27:24 pm

Hi all, just an update I found the common pin to just fall in the board holding the resistors and I had already gone out today and bought a new one ,it was only a small ivestment and at least I know its new yet when I used the switch it still only operates on high so I think the contacts on the slidding switch must be worn so its a matter of just buying the switch and gritting my teeth :smile01:

 Cheers John.