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Is there any way to add a modern 12 volt AC unit in my 6 volt '41 Clipper? Or is there some way to change the whole system over so everythings works (including O/D tranny) on 12 volt?

The simplest way would be a combined 6/12 volt system. Add a 12 volt alternator in place of the generator. Install a 12 volt battery with a center tap or 2 6 volt batteries. Run everything 6 volt on 6 volts, all the 12 volt stuff on 12.

It is also possible to change completely to 12 volt if you can find a 12 volt solenoid for the overdrive. If the same model was made after 1955 there should be a 12 volt one. All the bulbs, heater fan motor, gauges etc need to be changed to 2 volts or furnished with a special 6 volt power supply. This is a common thing on hot rods and 12 to 6 volt converters are easily available, the old method by resistors or the new method of zener diodes.

Denny, do a search here on the website for 6 volt a/c. There have been numerous conversations on the subject. The main problem is there is no a/c compressor available with a 6v clutch. All the original Packard A/C compressors were clutch-less.

Thanks for the suggestions. Rusty, I guess I'm a little slow and a visual learner. What would the two 6-volt battery set-up look like exactly? How would you wire one thing for 6-volt and something else for 12 using the same batteries...ie: how's it physically wired? Thanks in advance!

Why could one just add another 6 v battery in series just to trip and keep the 12volt clutch engaged?
Keep everything else on 6V coming off the 1st battery?

You could but if in series, also need to think about how you are keeping the second battery charged. Also need to control the 12v to inside unit if tied in to regular system. Can get complicated.

Some have done it by hiding a totally independent 12v battery somewhere just for AC. Use a 6v relay operated by ignition switch to turn all on or off keeping the AC unit thinking it was a normal 12v setup. Advantage is total isolation and no chance of any 12v tie in with 6v. Inconvenience is in charging that second battery externally via charger. It may need to be done every day or so if a lot of use.

Others have added a small alternator just for the 12v battery. Mounting and driving that discreetly can be an issue.

With the size of the old generators, I've often wondered why both a small 12v and 6v alternator of 30 amps or so each couldn't be combined in a similar housing one in front of the other. Might even split the output from a single into two voltages although that gets to the voltage tie in again. Either could be made to look like a generator at quick glance ala PowerGen. It would then be no trick at all to hide a small independent motorcycle battery for AC somewhere if it were kept charged.

Even if something split were available, probably no demand though. It would be less than ideal for a solution. Purists still wouldn't want it and most others really wanting AC bad enough would convert to 12.

We went through ALL this and more in the beating a dead horse thread.

With all the trickery and whatnot, you could get a powergen alternator that looks like a generator and, except for the A/C setup, everything would look stock converted to 12volt.

The sanden compressor needs 7.5v to stay closed. Maybe a step up converter or setting the car up as 8 volt would work. That's the cheapest route but may not work 100%.

The best route is to go 12v and do it right.

Anything else in the middle would not be a good pay off for cost vs function.

The sanden compressor needs 7.5v to stay closed. Maybe a step up converter or setting the car up as 8 volt would work. That's the cheapest route but may not work 100%.

Even if the clutch stayed closed, there is still the issue of blower. All the 6v blower motors available now are pretty small for AC, size wise, power wise. Might be another issue trying to convert that side to work well even if a clutch solution is found.

"Also need to control the 12v to inside unit if tied in to regular system"

1. Could you explain that a little?

2. Also, would the 12v clutch pull down a large battery quickly?

3. I had a A Model Ford set up with a 8V battery. Little in the way of insruments but was hard on the old generator at night keeping the sealed beams bright. Especially when I tried to set up a heater blower. Motors are amp hogs.

The inside unit has a 12v blower motor. It also has the thermostat which actually turns the clutch on and off. Most units I'm aware of have a single switch to turn the entire unit on and adjust fan speed and then another knob or lever for the thermostat. That on/off switch is where the voltage actually goes first. Normally this would go to a 12v terminal controlled by ign switch--some directly, others thru a relay for the needed power so the unit would turn off when key is out. I don't think there is a 6v blower motor you could retrofit satisfactorily. There are heater blower motors but those are rather small both physically and output wise compared to the AC blowers. They can't easily handle the load of larger cfm blower wheels for the airflow and also you would have to fabricate a mount.

The clutch would pull some current but not as much as the blower usually. The bigger issue is if the voltage is not enough to have the clutch pull in and stay in hard enough. If not, there would be some slip and friction could easily overheat and damage the friction surfaces--or not turn compressor well enough to cool properly. There is a fair amount of load when the compressor is in operation..