By Glenn Goodspeed
June, 1998
I used my last two cans of Freon R-12 on May 18. I remember the date because I got curious as to when I had added Freon last year. When I looked it up in the little notebook where I record such things, it was May 18. I guess I can only stand a certain number of hot, humid days before I have to do something about the air conditioner in the P1800.
Since I replaced the worn-out stock B-18 engine with a rebuilt B-18 bored to B-20 size, the car has run a little too hot in the summer. Last year it was all I could do to keep it from overheating, and of course the first step in stopping radiator boilover is to turn off the air conditioner.
This year I decided to add an electric fan in front of the radiator to cool things down a little and to prepare for the conversion to R-134a, which produces higher temperatures in the condenser than R-12. Since I installed the electric fan, I have not had to turn off the air conditioner. And Nature obligingly offered a week of 100-degree weather to help me test the system.
I'd been eyeing the eighty-plus-dollar fans in the J.C.Whitney catalog and other places. Didn't really want to pay that much, but was resigned to it, when I noticed that the local Auto Zone parts store had a good selection of fans. I picked a ten-inch Imperial (made in USA) that came with wire, mounting parts and a switch for only $55. It was strictly manual control (no thermostat), but I figured it would be a lot of trouble to get a thermostat to work right anyway.
It took half a day to install the fan, and it took that long only because I spent an hour or so trying to figure out the best way to fasten it to the car. The mounting parts consisted of four serrated plastic ties to be inserted through the car's radiator and then through mounting holes in the electric fan. The ties were fastened with plastic buttons that used the serrations to ratchet to a tight fit.
After considering various ways of mounting the fan by installing bolts, brackets and screws in the car, I gave up and used the supplied hardware (or should that be plasticware?) to fasten the fan to the a/c condenser. It ended up looking and feeling much better than I thought it would.
The instructions that came with the fan said to remove the blade and flip it over if I wanted to install it in front of the radiator. I did this, but when I started to do the wiring, the instructions said to reverse the wires if I was installing in front of the radiator. I wondered why, since I had already flipped the blade over, so I decided to try it wired straight first. Sure enough, the fan blew air the wrong way, so I reversed the wiring and it began to work perfectly.
I opted not to use the black plastic toggle switch that came with the fan, because I already had a good chrome toggle switch installed from an earlier attempt to use an electric fuel pump. (The electric pump was too noisy for me, so I went back to the original kind.) The switch is mounted in the under-dash panel where the fresh air and choke controls are located on my '63. It draws power from a switched terminal on the ignition switch, so it will be turned off with the ignition if I forget to turn off the toggle switch.
I normally switch the fan on whenever the car is moving less than thirty miles per hour and then switch it off when I'm on the open road. It doesn't make the engine temperature go down, but it does keep it from rising. Altogether, it was a worthwhile project, and it was the first step in converting to R-134a, which I have managed to put off as long as possible.
August, 2007
I have received reports from two owners of later model 1800s who found that there was not enough space in front of the condenser to mount a ten-inch fan. When the fan is positioned, the front edge of the hood comes into contact with it when the hood is opened. In fact, this happens on my car, but the hood only touches the fan lightly when it is fully raised. Once I set the hood back into its locked open position, there is an inch or so clearance.
Considering the tight clearances in this area as well as the inevitable differences between individual cars and electric fans, I advise anyone contemplating this addition to do some careful test-fitting before securing the fan. In particular, you should open and close the hood with the fan temporarily positioned on the condenser.
On another subject, the electric fan draws substantial power. If you wire it through the ignition switch as I did, make sure your ignition switch is designed to handle the extra current. If you're not sure, you can use a relay to reduce the current draw on the ignition switch or wire the fan directly to a battery lead. My ignition switch was an aftermarket unit, and it served me well for several years. A replacement switch failed with drastic consequences. You can read the story here: Ignition Switch Replacement.