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| | | | Joined: Dec 2011 Posts: 133 Wrench Fetcher | | Wrench Fetcher Joined: Dec 2011 Posts: 133 | I am rebuilding my heater assembly and am not sure if it has ever been upgraded to 12v. This heater has two motors, one for the cab and one for defrost. I tested both and they work but did not run them long since I was testing with 12v. Question:
1) Is there any way to tell if it is a 6 or 12 volt motor.
2) If six volt, can I just install a voltage reducer for these.
3) This heater has a Chevrolet metal decal on it with a rectangular core, no fresh air. Would this be original to a "48" cab. Name on back plate is Harrison HO-147.
Thanks
If you never tell a lie, you never need to remember what you said.
| | | | | Joined: Feb 2002 Posts: 12,029 Cruising in the Passing Lane | | Cruising in the Passing Lane Joined: Feb 2002 Posts: 12,029 | I don't think those heaters with 2 motors were made into the 12V years, pretty safe bet it has 6V motors unless the truck has had a spendy conversion to 12V .... most of the small motors have voltage imprinted on them, otherwise if you can round up a 6V battery or a charger with dual voltage function you should be able to tell, a 12V motor would have a hard time starting on 6V and turn way slow
yes, you could use a pair of reducers, if there's room to mount them so they safely dissipate the heat
Bill | | | | | Joined: Dec 2011 Posts: 133 Wrench Fetcher | | Wrench Fetcher Joined: Dec 2011 Posts: 133 | Would I be better off just changing them to 12 volt over using two voltage reducers. Mounting the reducer under the dash is not a problem, I just want to avoid future problems.
If you never tell a lie, you never need to remember what you said.
| | | | | Joined: Sep 2006 Posts: 3,596 'Bolter | | 'Bolter Joined: Sep 2006 Posts: 3,596 | I would like to see a picture of this 2-motor heater. | | | | | Joined: Sep 2001 Posts: 29,270 Bubba - Curmudgeon | | Bubba - Curmudgeon Joined: Sep 2001 Posts: 29,270 | | | | | | Joined: Feb 2002 Posts: 12,029 Cruising in the Passing Lane | | Cruising in the Passing Lane Joined: Feb 2002 Posts: 12,029 | yes Tim, "separate electric switches" is the key, my 46 GMC had one that looked different than that one, but had the dual paddle switch unit that someone has posted a picture of in the past
yes Bart, changing to 12V motors would be preferable to using reducers, which get very hot and add one more failure possibility
Bill | | | | | Joined: Oct 2006 Posts: 9,671 'Bolter | | 'Bolter Joined: Oct 2006 Posts: 9,671 | Or, you could avoid using any dropping resistors all together and wire the two in series
dropping 6v across each one. Of course you wouldn't have the choice of running each one
separately any more.
Since the truck has apparently been altered from it’s original design, i.e., converted to
12v, it shouldn’t make any difference to you if you use a single switch for the
heater/defroster.
Denny Graham
Sandwich, IL
Last edited by Denny Graham; 02/16/2013 12:39 PM.
Denny G
Sandwich, IL
| | | | | Joined: Dec 2011 Posts: 133 Wrench Fetcher | | Wrench Fetcher Joined: Dec 2011 Posts: 133 | The heater shown by tclederman is the one I have. Denny, thanks for that advice. I think I will bench test these motors wired in series and see how that works before I spend $120 on two new motors. At this point I am not sure how much it will even get used in cold weather. I need to check on the year of this cab since it is not the original cab. I have the plate that came on it that I should be able to tell for sure if it is a "47" or "48".
Last edited by Bart_Bosco; 02/17/2013 10:32 AM.
If you never tell a lie, you never need to remember what you said.
| | | | | Joined: Aug 2012 Posts: 566 Shop Shark | | Shop Shark Joined: Aug 2012 Posts: 566 | I dont know if this is possible but if you ohm the motor out providing its good, can you tell the voltage by a formula? I guess if you knew how many poles it has. I know you can do that on a/c motors. Not sure about d/c.
"As I lay rubber down the street, I pray for traction I can keep, but if I spin and begin to slide, please dear God protect my sweet ride." -Amen 56 Chevy 3100 | | | | | Joined: Oct 2010 Posts: 1,232 'Bolter | | 'Bolter Joined: Oct 2010 Posts: 1,232 | I believe that this would be a good choice to operate and protect your 6v heater motors and switches on 12v ... > CLICK - Ron Francis Voltage Reducer
- Lonnie My '54 3104Photos that I have shared on Stovebolt via PhotoBucket are no longer available. Please contact me if you want a photo from an old post. lonniecook [at] aol [dot] com. I sold my '54 3104 12/12/2017, but I still visit Stovebolt. OLD STUFF ... houses, furniture, cars, wine ... I love it all | | |
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