Electric cooling fan system

The electric cooling fan that I used was a flex lite model #210 puller type; the best price that I could get was from Summit racing. The reason that I like this unit is that it comes with its own shroud and the motors are of a type, that has no brushes. Also, the motor is a ballbearing type. The fan relay system that they sell, was not to my liking because it required that the sensor was to be put into the the top outlet of the radiator between the top hose and the radiator, this proved to be unreliable because the top hose popped off of the radiator on me. The system that I used was from a GM car that I got was from relay mount from the wrecking yard. The original unit that I got from the wrecking yard was from a 1983 Buick skylark. I have since returned to the wrecking yard to get a unit from a 1986 olds. The reason that I got this unit, was that the relay mount screws down to the car, and the relay plugs into the mount

Wiring of the relay is as follows :

The underside of the relay has these numbers on it

1. Pin 1) Fused power from battery ( 10 or 12 gauge wire)
2. Pin 2) power to fans (10 or 12 gauge)
3. Pin 3) Wire to temp sensor in block
4. Pin 4) Power wire (fused) from b+ after key. If fans are to run with key off then to battery. Note : If outside key then have a strong battery. (mine died twice)
5. Pin 5) Not used

If you go looking for this mount in the wrecking yard,

the mount system is on top of the heater a/c box under the hood.

Shows the fan relay that I got from the wrecking yard that is from the Olds.

The picture, shows the fan sensor system, that you get from summit racing, when you order the part. The wire that is in the picture comes with the sensor. What it is for is if your car does not have the GM connector for the sensor, it is of the type that does not fall off, it has a male spade on the other end to connect onto your wire system.

1. Shows the fan sensor parts, from Summit Racing

Sensor system

The sensor in the picture is also purchased from Summit racing. It is actually made by HYPER-TECH

The part # are as follows

# 4028 on at 200 degrees off at 185 degrees-aluminum heads

# 4026 on at 174 degrees off at 164 degrees-cast iron heads

The sensors actually screw into the cylinder head of the engine. If you have aluminum head then it will screw directly to the head if you are using a cast iron head then you will have to use a brass adapter, because of this then the lower temp unit works better. The reason for this is that the sensor does not go as far into the head. So the operation is a little slower so the temp is slightly higher for the on and off cycle of the fan system.

The Chevy heads are reversible so you have a place to mount the sensor in the passenger side head between cyls, 6 and 8 above the starter, so that you do not have to disturb the coolant gauge sensor of the car.

Editors Note: At the top of this photo, you will see the bonnet strut,

that people on the mail list, were questioning a while ago