12 Volt Conversion

[JStinson]

I know this subject has been worn out badly. I was unable to find threads about this particular issue, so I decided to do what any clutterer would do...start a new thread.

In any event...I got a NOS heater kit from Midwest Military. The plate on the fan/core says 24 volt. It's a beautiful kit, and I want badly to use it. I'm keeping the truck as a 12v system, someone had already converted it years ago. Can I use that fan? Surely there is something that can make the fan work on that system. Tell me I didn't waste my money.

[gusbratz]

you can run it off of 12v it just won't spin as fast. or you could add another battery to yours in series, and pull power off of them both for the fan but off of only the 1st one for the truck.

[gusbratz]

but the 2nd battery on line is going to lose its charge

[JStinson]

you can run it off of 12v it just won't spin as fast. or you could add another battery to yours in series, and pull power off of them both for the fan but off of only the 1st one for the truck.

Is this the only option? Could the fan not be rewired to run properly off the 12v system?

[Frank Irons]

I run my 24 volt M37 on 12 volts without a rheostat. The other option is to get a 12 volt blower motor from NAPA or other auto parts store. I was going to get a new 12 volt motor but found that the 24 volt motor spun quite fast on 12V.

Frank

[gusbratz]

most blower motors control switches have a clouple of preset resistors in them. When you switch to a lower speed you are going through a resistor and lowering the motor voltage. so running 12v would just be a lower setting. if it is fast enough to keep you happy and warm them run with it. You could have the motor rewound but I don't know who or where and I bet it would be cheaper to convert your truck back over to a 24v system. most people don't rewind motors anymore since labor is so expensive. we used to send motors out at work but now it is cheaper to buy a new one.

[Charles Talbert]

Your best option is to simply get a 12 volt replacement motor, easy find at any good parts store.

[JStinson]

most blower motors control switches have a clouple of preset resistors in them. When you switch to a lower speed you are going through a resistor and lowering the motor voltage. so running 12v would just be a lower setting. if it is fast enough to keep you happy and warm them run with it. You could have the motor rewound but I don't know who or where and I bet it would be cheaper to convert your truck back over to a 24v system. most people don't rewind motors anymore since labor is so expensive. we used to send motors out at work but now it is cheaper to buy a new one.

That brings up another discussion entirely. Would it be easy to convert the truck back to a 24v system? Cost effective?

I would really like to put it back to 24v, since that's how it was when it rolled off the assembly line, but I fear that it would be more of a headache in the long run. How about parts availability for such a setup?

Thoughts?

[Charles Talbert]

Less $$ for sure to go a 24 volt back to original route than it is to convert to a really reliable 12 volt system from 24 volt. Original parts are not hard to come by and not nearly as expensive as going completely (the right way) from 24 to 12. The 24 volt system is a very reliable system. We don't recommend changing from it where the original engine is to be used unless the specific vehicle application dictates the need for a 12 volt system.