Hi All, fuse blew for the heater fan motor, checked switch o.k., replaced fuse...no others bad, have continuity thru switch o.k., ground o.k., voltage regulator checks o.k.. key turned and new fuse immediatly blows. disconnected heater hot and ground but when I check for continuity thru motor I get no audible tone...only a .080 reading...?
I am assuming there is an issue inside the motor. Believe it or not I think it is the original 6 volt and I had set it up with a reducer to run on the new 12v. system.
Do the 6v. motors go bad quickly running on the reducer and 12v's?
Will I get higher r.p.m.'s out of a true 12v. motor? (better defrost)
Just thought I would throw the questions out there before I rip this thing out from under the dash....
Anybody got an extra 12v. fan motor that would fit a '54 they want to sell?
thanks, Ed

 

Do a search on heater fan motors, there are a couple 5-page threads with all kinds of alternatives. Is this a fresh air heater or recirculating?

 

Thanks for the thread suggestion....but I figured out the issue. Seems when I installed my tack I needed a ground but unknowingly the hot lead for the fan switch had come loose and I assumed it was another ground and thus the "short to ground"! All is right and working properly now. I will however still explore the 12v. motor replacment fot the future.
thanks, ED

 

You have one of those weird "chicken or the egg" situations going on.

A voltage reducer will not reduce unless it has voltage flowing through it. So your heater motor has to be turning in order for the reducer to drop the voltage.

It also depends on how you have things wired - the order, and the wire size - needs to be 12 AWG for a reduced 6 volt set up.

The only voltage reducer I have found that will carry enough amps to handle a rheostatic heater switch is a Vol-ta-drop. They aren't being made any more.

Also, the switch you have has to be the one made for the motor. So if you are running a 12 volt switch and a 6 volt motor on a reducer the system is going to tilt.

And no, you will not get extra rpms out of a 12 volt motor powered with a 6 volt reducer. What you will get is popping circuit breakers and possibly a fire! Heater switches get hot on lower settings - don't mix match.

Find the correct switch for the motor and install a vol-ta-drop if you you can find one.

Otherwise, replace the 6 volt motor with a 12 volt, get a matching 12 volt switch.

Also, check to make sure none of your motor wires is chaffed against the heater case. If you are popping fuses without the heater being on, you have as hort some place - between the power source (fuse) and switch.