Classic Mustangs (Tech) Technical discussions about the Mustangs of yester-year.

How to Test Heater Blower, Switch, Resistor

Thread Tools
 
Search this Thread
 
Old 11-10-2010, 01:22 PM
  #1  
unit91
3rd Gear Member
Thread Starter
 
unit91's Avatar
 
Join Date: Oct 2006
Location: Virginia
Posts: 889
Question How to Test Heater Blower, Switch, Resistor

Asked these questions on General Tech, got many views but no responses. I have removed the complete heater assembly from my 68. The blower has two wires (brown and yellow) coming from it, and the switch is 3-speed. How can I test the blower motor, resistor, and switch to see what is failing to work?
unit91 is offline  
Old 11-10-2010, 09:07 PM
  #2  
tx65coupe
5th Gear Member
 
tx65coupe's Avatar
 
Join Date: Dec 2008
Location: Texas
Posts: 4,462
Default

First I would check the fuse. Then see if there is power at the blower motor at all the different speeds. Use a test light or multimeter. You could also hook up the blower motor directly to the battery and see if it runs. Next check to see if there is power at the resistor and then see if there is power at the switch.
tx65coupe is offline  
Old 11-11-2010, 11:40 AM
  #3  
unit91
3rd Gear Member
Thread Starter
 
unit91's Avatar
 
Join Date: Oct 2006
Location: Virginia
Posts: 889
Default

OK. If you have the time, can you explain exactly how to do those tests? Like connect what to what, etc., etc.. If the motor isn't the problem I don't want to connect it improperly and end up screwing it up myself. I sure would appreciate it.
unit91 is offline  
Old 11-11-2010, 12:23 PM
  #4  
69mach1377
5th Gear Member
 
69mach1377's Avatar
 
Join Date: Aug 2004
Location: ABQ, NM, USA
Posts: 2,593
Default

This is where a schematic would be helpful.
69mach1377 is offline  
Old 11-11-2010, 03:36 PM
  #5  
tx65coupe
5th Gear Member
 
tx65coupe's Avatar
 
Join Date: Dec 2008
Location: Texas
Posts: 4,462
Default

Just use a multimeter or test light with probes on the end to see if you get power with the light or how many volts with the multimeter. You need to unplug it and probe the terminals at the connector.

Try looking here for schematics. There is additional wiring info here.

http://www.hammar.dyndns.org/~djhamm...wiring1968.htm

tx65coupe is offline  
Old 11-11-2010, 04:59 PM
  #6  
69mach1377
5th Gear Member
 
69mach1377's Avatar
 
Join Date: Aug 2004
Location: ABQ, NM, USA
Posts: 2,593
Default

Excellent!
69mach1377 is offline  
Old 11-11-2010, 08:00 PM
  #7  
unit91
3rd Gear Member
Thread Starter
 
unit91's Avatar
 
Join Date: Oct 2006
Location: Virginia
Posts: 889
Default

Great! Thanks a million!
unit91 is offline  
Old 11-12-2010, 05:16 PM
  #8  
tx65coupe
5th Gear Member
 
tx65coupe's Avatar
 
Join Date: Dec 2008
Location: Texas
Posts: 4,462
Default

Your welcome. I hope that helps.
tx65coupe is offline  
Old 11-14-2010, 10:47 AM
  #9  
unit91
3rd Gear Member
Thread Starter
 
unit91's Avatar
 
Join Date: Oct 2006
Location: Virginia
Posts: 889
Default

OK. I hooked the system up while it was out of the car according to the wiring diagram. If I hook the blower directly to the battery it works, only one speed of course, sometimes it's pretty quiet and sometimes depending on the angle I'm holding it at it's pretty noisy.
When I use the switch, sometimes I get 2 speeds (lo & hi), sometimes I get all 3 speeds, sometimes I get nothing.
unit91 is offline  
Old 11-16-2010, 12:53 AM
  #10  
tx65coupe
5th Gear Member
 
tx65coupe's Avatar
 
Join Date: Dec 2008
Location: Texas
Posts: 4,462
Default

That sounds like either the switch is dirty or the blower resistor is bad.
tx65coupe is offline  


Quick Reply: How to Test Heater Blower, Switch, Resistor



All times are GMT -5. The time now is 12:30 AM.