Hello, The 52 f-1 i bought came with the heater fan not hooked up. The rest of the truck is 12volt but the heater was still 6 volt. I bought a reducer from Lmc truck. I hooked it up to the reducer before the heater switch with the wires going the right way "the battery side going to the power source", but nothing happened just smoke from the reducer! the wire for the power went to a selinoid under the dash. Did i do this right or whats the right way to do this thanks!

 

Well, it depends on what kind of reducer you bought.

I have a 51 Magic Aire Heater on my 51 with a 6 volt motor (your 52/my 51 - same motor for Magic Aire - and no 12 volt replacement made).

I use a "Vol-ta-drop" to reduce voltage for my heater. But the heater motor draws a few more amps than th enormal reducer will handle especially if you have an adjustable rpm rheostatic switch as opposed to the three position (off, low, high) pull switch.

When using the Vol-ta-drop, you will need to connect the two out put posts in series to provide enough amps to drive the motor, and you want to be sure to put an inline fuse holder (like on a stereo) between the reducer and motor.

Here is a picture of the Vol-ta-drop and how to wire it:





12 volt "switched bus" would be whatever you use to provide electricity to accessories that are switched on with your ignition switch. I have a separate fuse holder for items switched on, but you might also be using the "ACC" post on the ignition switch. No big diff.

The wire shown in the wiring diagram going to the heater is actually going up to the heater switch from which power is supplied to the motor

The vol-ta-drop will get hot, especially if you use a rheostatic type switch (and it will get hot too). Someimes they "smoke" a little the first time you use them and burn off coatings, fingerprints, and dust. Also, the appliance you are reducing opwer to has to be "On" for the voltage to get stepped down. The reducer posts will red 12 volts if there is no draw.

 

Thanks julie, Where can i get one of those reducers at? i didnt really find a good place googling that name, I got the motor to run when i took it out of the truck, I hooked up a jump pack to it and ran fine on both speeds, i tried the reducer i bought but couldnt get the current to go threw it, I had to undo the ground from the fan and hook it to the neg on the jump pack to get it to spin.

 

For about the same cost, you can replace the fan motor with a 12v motor. You need to know these things, then go to a NAPA or AutoZone and ask to look thru their Siemens catalog (paper catalog):

Shaft diameter
Rotation (CW or CCW)
Length of motor housing
Mounting method (most of ours use the 4 bolts that run thru the motor)

The '51-'52 box heaters use SiemensVDO #PM354
$26.99 @ AutoZone

A '50 Ford car uses Siemens/NAPA #455-1020 or 655-1020.


A motor built for 12v is a better way to go IMO.

 

i did read on another post about the motor swap is the autozone one a direct fit or alot of work? and do i just hook the hot wire to the post on the starter selinoid with an inline fuse?

 

Any idea if they make a 12v heater motor for a 55 F-100 that you can get at autozone or napa.

Thanks Scott

 

Wouldn't you want to use a little smaller than a 20amp fuse seeing as that adapter looks to be rated at 12amps combined on the outputs?

 

Just a guess, but since they changed to 12v in '56, you may just need to get a stock '56 motor? I don't know enough about Mid-50s to say. Siemens makes over a hundred different motors just for American cars, they surely have one for yours. Let me know what it is when you find it, I'm keeping a list.

 

We've had this discussion many times before Ross, and you know as well as I do that replacement 12 volt motors are available for 48-50 Magic Aire (with the in fender motor box) or 51/52 recirculating heaters (and youhave nicely provided the part numbers for those on occasion). But there is no replacement motor with the right (compact) dimensions and RPM to change to 12 volt on a 51/52 Magic Aire. If he has a "Recirculating Heater" and wants to go through the effort of finding a 12 volt motor that would be fine, but I'm assuming he was talking about a reducer because he couldn't find a 12 votl motor for his heater adn thus it was the Factory Installed Magic Aire - as I stated in my initial response. How do youtell the differrence? The Magic Aire heater has a door onthe far right side center that opens to allow cockpit air in or closes to take air from outside. Normally the Magic Aire has four control ***** as opposed to the two (motor on/off, and heat/defrost) for the recirculation heater.

Nope, the reducer does not have a constant output but rather it is developed on both draw and Generator RPM. It may vary by 3-4 amps in short pulses. The output rating in the Vol-ta-drop in series is 12 amps, but that by no means indicates it's tolerance. If you were to use a 15 amp fuse it would burn out regularly from amperage surges. Plus, also remember, you are protecting the heater switch and motor with the fuse, not the reducer. 20 amps "converted" is correct.

Try and find a 56 Motor. I'll bet Number Dummy could find a couple, but they are not sold over the counter regularly. And if one was made for general use I'm certain the word would be out to both us and the resto parts houses.

There is a repro 56 car motor available. They are not the same. How different the dimensions are or how easy to adapt I'm not sure....I'd not want to try it, they are $185.00.

Here's a pic with a C&G part number:

 

just remember those voltage drops get HOT so keep them away from anything that could catch fire.

 

Yeah, and the use of dropping resistors fundamentally bothers me for just this reason. Not only that, but the voltage dances around depending on the load. That's not good for the accuracy of your guages and I don't like the idea of running multiple resistors for each separate device. My truck will run a 12V system but retain its 6V wipers, heater fan, horns, and guages. I've had my eye on one of these:

Voltage Reducer Regulator 12 VOLTS to 6 VOLTS 20 AMPS:eBay Motors (item 140366013132 end time Jan-06-10 20:41:44 PST)

Solid state is a far more elegant solution without the heat and voltage fluctuation issues. That one is rated for 20 amps and he also has one that is good for 15 amps. It's considerably more expensive than a simple resistor, but I feel it would be worth it on a daily driver.

I've got schematics around here somewhere for one, but it won't handle anywhere near that much current. One of these nights, things are going to be slow at work and I'll dig that up and see if I can beef it up a little. I think plans for a "build it yourself" solid state reducer would be popular around here.

 

Actually Julie, I don't think I've ever participated on any discussion of Magic Air heaters other than to suggest checking the Siemens catalog. If someone has the numbers that work, I'd like to see them, or else the required dimensions and rotation etc. This comes up all the time, but since I don't have a MA (or a mid-fifties) I haven't paid a lot of attention.

Just offhand, there are tons of Siemens motors that look just about like that '56 motor, so I'm sure there is something that will work with minor modifications. But their catalogs for US parts aren't on-line, the paper catalogs are all that's available.

 

I think I have that schematic somewhere too, and it would be useful for wipers in 6-to-12 conversions.

 

Hmmm. I've had on ein my 51 for 6 years now. I was certain not to try to draw more off of it that it was rated for. It gets warm, but not hot. I can touch it with comfort. So I guess like most other things electrically, it has to be "properly" used.

Like most things on your truck, use of certain items, there like or dislike, is a matter of personal experience and preference. I've never had one bit of problem with my Vol-ta-drop, or the gauge voltage reducer. The one gauge I use a reducer on is completely accurate and not affected by varying voltage or amperage. As a matter of fact, they work perfectly.

Sorry Ross, I thought, perhaps mistakingly, that in all the times we had talked about this and you had offered your part numbers for the 48-50 heater motor and recirc motor replacements, you were in on the discussions that were there concerning the Magic Aire and the non availability of replacement 12 volt motors for them.

 

Well me being "normal" I fixed my 12 volt to 6 volt problem in the "hot-rodder" way, right or wrong it has worked great for a couple of years.
I stole the heater resistor pack from a 78 F250 heater assembly, then I put it in series with the heater motor power wire. I forget which resistors I went thru in the pack but I got it as close to 6 volts as I could. Then I cut a corresponding shaped hole in the heater/defroster output ducting, and installed the resistor pack so that the heater output air flowed across it to cool it, just like the 78's factory setup. I guess if I was concerned I could actually add different speeds by running thru different resistor combinations, but I just have it running at approx 6 volts all the time.
May not be for everyone, but you can't really see this mod and besides my truck is far from stock