How to fit an electric fan to your Z

by Salman SHAMI

This weekend I finally changed over to an electric fan in my Datsun 260Z. I used a thermo electric fan out of a Nissan Pulsar. which I bought from the wreckers for $50. This fan is designed to be fitted behind the radiator, i.e between the radiator and the engine. I wanted to install it ahead of the radiator to improve efficiency. Reversing the fan was simple. I took the nut of the front and simply pulled the fan off and fitted it reversed. Naturally I also reversed the polarity.

The fan came with a housing with three brackets welded to it. One on one side and two opposite to it. All those brackets had holes. I managed to align the hole in the single bracket with a pre-existing hole by enlarging the hole in the fan bracket. I bolted the fan using the single hole. For the opposite side I cut a thick aluminium strip 35.5 mm long. This I bolted vertically onto the car and bolted the other two brackets on to it. Naturally I had to first make holes in the aluminium strip and in the body. The fan was now fitted ahead of the radiator on the right hand side in front of the water intake. This I did to remove more heat because that is the hottest part of the radiator.(There is about 6 inches of radiator that are not covered by the fan.) Because I had no power tools this took me 2.5 hours.

The next day I resumed the job. First in line was the thermostat switch. This comprises a copper bulb and a capillary tube filled with some fluid which expands and activates a switch through a lever. The bulb is connected to the switch housing by the thin copper capillary tube. The thermostat kit comes complete with a tapered rubber ferrule with a groove in it so that the bulb can be inserted into the radiator hose and the capillary can pass through the groove in the ferrule. This helps to prevent leaks. BTW, the switch is similar to type used in fridges.First I removed the top radiator hose and inspected it. It was starting to look a bit dicey to me so I threw it out. Then I fixed the thermostat onto the inner mudguard and carefully bent thermostat's capillary tube to enable me to run it along the side of the radiator into the upper hose.

I applied some silicon paste to the water housing pipe and installed the new radiator hose on it and tightened the clamp. Then I did the same to the radiator pipes and stuck the rubber ferrule on to it. I passed the bulb and capillary tube into the hose and pressed the capillary tube into the groove on the ferrule. Then holding the ferrule with a screwdriver (because it was slipping and sliding around due the silicon paste) I slowly moved the hose onto the pipe. I had the adjust the capillary tube because it had moved a millimetre or so out of the groove in the ferrule but finally I got it right. I tightened the clamp with the clamp bolt 180 degrees away from the capillary and ferrule.

Electric connections came next.I connected the input of the thermostat switch with ignition. For this I took the current off the input to the resistor of the distributor circuit. The output of the thermostat went to one terminal of the switching circuit of a 40 Amp relay switch. The other terminal of the relay's switching circuit was connected to ground.

Then I connected one terminal of the relay's switched circuit to the battery (through a fuse) and connected the other terminal to the fan's positive terminal (formerly negative). The negative terminal of the fan was connected to ground.

After finishing I checked all bolts and connections and then started the car. I checked the working of the fan and then taped all the loose cables. Then I removed the original fan and adjusted the thermostat switch to only operate the fan slightly above normal operating temperature.

I topped up the radiator and went for a test drive. The car certainly warmed up quicker, was quieter. So much so that I started to hear a whistle from the mirror. I felt an increase in acceleration and an increased willingness to rev. Which is not surprising since the old fan weighed about 5 kg. Since it was a cool night the fan really only came on when the car was idling. Over all it kept the temperature constant. I have yet too drive it in summer and see how well it does in a traffic jam. If necessary I will then fit a second fan to either run in parallel or sequentially.

Here are some figures: