Posted - 04/12/2007 : 1:11:33 PM
| Caprice-9C1 Fan Delete
For 91-96 B-Bodies
by Bob Ignash
If you are one of the many Caprice or 9C1 owners who are tired of the roar of the mechanical fan, which robs you of HP and gets in your way when you are working on your car, then here is how I made the change to the factory electric fan.
Remove the Mechanical fan and mounting hardware. Remove the top fan shroud. There are bolts along the top of the radiator and down along the side that connect it to the lower half of the shroud.
Remove the 4 nuts that hold the fan blade on and remove the fan and pulley. From the underside of the car, remove the 2 bolts that hold the lower half of the shroud on and remove the shroud. The bracket that holds the idler on is held on by three of the water pump bolts. They will need to be removed along with the bracket. Replace the bolts with shorter 3/8x16x4 bolts. They can be bought at any hardware store. Use thread sealer on the threads.
Replace the upper fan cover with one from an Impala or Caprice with dual electric fans (GM part # 10281082= $9.09). All prices for parts are prices I got from GM parts direct. Install the electric fan unit. It is held on by a slot on the bottom and a screw on the top and side. I found it easier to remove the screws on the other fan to match them up for size. There is a long one on top and a short one on the side. If you are buying a new fan they come in three pieces.
Motor part # 22137318 = $47.25
Fan Kit part # 12365300 = $48.50
Motor kit part # 22135365 = $57.50
You will also want to remove the crankshaft fan pulley...Just 3 bolts.
Start by disconnecting the battery. Then remove the power supply "large cable" from the underhood fuse box. Disconnect the plug in connector on the back side of the box. This is done only to make it easier to work on. Remove the bolts that hold the box in place. The box is actually a box within a box. To separate them, find the retaining clips that are located between the walls of the box and remove the outer shell. Now you can get to the wires on the back of the fuse box. Using the diagram on the lid of the fuse box, locate the empty 40 amp fuse position for the primary fan. Using 10 gauge wire and a female spade connection, insert from the bottom of the fuse box, the connector into the unused side of the fuse connection. You may need to enlarge the slot a little to insert the connector. The other side is switched power. Install a 40 amp Maxie fuse. Run enough wire to go where your relay is going to be mounted. The fender well is a good location. Now using the diagram on the lid of the under hood fuse box, locate the 10 amp fuse labeled primary fan. Connect a 14 gauge wire to the fused side, to the location where the relay will be mounted. Reassemble the two parts of the fuse box; neatly route the wires. Reconnect the power supply cable to the under hood fuse box and reconnect the plug on the back.
3. Wire the PCM:
Connect PCM pin, Part # 12084913, $1.11 to a roll of 20 gauge wire. Remove the Red 32 pin connector from the PCM. Open the plastic cover over the wires. There are 3 little plastic tabs that allow you to do that. Insert, "Push" the pin into position # 11. They are numbered on the connector. That is the ground signal from the PCM to turn on the relay. You can see that the pin goes all the way in as it is made of clear plastic. Reinstall the connector on the PCM. Route the wire to the location of the relay.
4. Wiring the relay:
Mount a 30 amp relay to your fender well. Four position relays are labeled by numbers. Numbers 30-85-86-87. At # 30, you will connect the 10 gauge wire that you have coming from the 40 amp fuse from the under hood fuse box. At 85, you will connect the 14 gauge wire you have coming from the 10 amp fused position in the underhood fuse box. At # 86, you will connect the 20 gauge wire from the PCM. At # 87, you will run a 10 gauge wire to the positive side of the fan motor. From the negative side of the fan motor, you will need to run a 10 gauge wire to a good ground. There is a ground just in front of the battery that is easy to reach. If you can find a plug connector for the fan, perhaps at a junk yard, it will look much nicer. If not, you can use insolated spade connectors.
Be sure to check all wiring and perform a complete test of the system prior to operation. I hold no responsibility for this modification. It has worked great for me. The primary and secondary fan come on independently of each other at the predetermined temperature programmed into the PCM. The roar of the old mechanical fan is gone. Vibration from the fan is gone. Getting to areas in front of the engine are made much easier. Plus it frees up some wasted HP.
If you have any questions, please send an email to Bob Ignash.