Guide on Replacing a Early Thermofan Switch from the Top!

Dan84944 · 01-05-2021, 06:39 PM

*THIS IS FOR N/A CARS ONLY*

Okay so I just replaced my fan switch. Everyone was saying to get it from the bottom, naturally I did not listen. They also said to drain the radiator. Blah Blah Blah. Anyone who needs to replace their switch, I'll let you know, that it is MUCH easier replaced from the top. The amount of work needed to remove the fan shroud/fans is already more than the amount of effort needed to go through the top.

The procedure goes as follows.

1. Ensure you disconnect the battery, by loosening the bolts on the connections. This is so that the fans do not come on while you are attempting to replace the switch and remove one of your fingers, pro bono.

2. Remove the 10 millimeter bolts on the air box bracket. The two attached to the air box, not the chassis, will come out with a ratchet and extension just fine. There is one small 10 millimeter nut that is more towards the front of the car, under the front. Use a wrench on this one.

3. Next proceed to take off the top of the air filter housing. There are several phillips head screws WITH SMALL WASHERS on them that will need to be taken out.

4. Remove the air filter and bottom housing. This is done by taking out 4 ten millimeter bolts holding the barn door AFM to the filter housing. Once done, look towards the firewall, find the two ten millimeter bolts holding the line to the air box. take them out as well. Next, remove the 2 ten millimeter bolts holding the air box to the chassis. These will be directly to the driver's side of the two bolts you remove off the line. They will be on the firewall side.

5. Remove bottom air filter housing. Now get a 29 millimeter *DEEP* socket with a 3 to 4 inch extension.

6. Proceed to remove the fan switch. The reservoir will have a line coming off the bottom of it which can be bent out of the way with little to no effort. Now simply unscrew the old fan switch from the radiator. Remember to check if your threads are brass or plastic. Brass needs to be torqued to 28nM and plastic threads are 20nM. (Clark's Garage Home Page). If you are like me, and did not drain the coolant, then prepare a drain pan under the car, and screw out the switch slowly to where it would be easy to take it out quickly. Take out the switch as fast as you can. Have the replacement ready nearby. Make sure that the gasket is on the threaded side of the switch. After screwing in, plugging in, and torqueing down the switch, repeat steps 1-4 in reverse order.

And that is how I did my switch in less than 30 minutes. You can choose to do the same or go from under the car, but this method worked well for me.

16again2009 · 16again2009's Garage

I did exactly the same thing last week. Except there was not enough room between the fan shroud and the switch for my socket to slide on. It was too thick. So i took the fan shroud loose and just moved it down a bit and it came right out. I guess I'll need a thinner socket next time.

Dan84944 · 01-06-2021, 07:51 PM

Quote:

Originally Posted by 16again2009

I did exactly the same thing last week. Except there was not enough room between the fan shroud and the switch for my socket to slide on. It was too thick. So i took the fan shroud loose and just moved it down a bit and it came right out. I guess I'll need a thinner socket next time.

I have a Husky 29mm socket from home depot that was 15 dollars and slid on with little to no effort! I highly suggest checking it out next time your switch decides it had enough!

Johnny O · 01-07-2021, 05:02 AM

Quote:

Originally Posted by Dan84944

I have a Husky 29mm socket from home depot that was 15 dollars and slid on with little to no effort! I highly suggest checking it out next time your switch decides it had enough!

Hi Dan84944, what degree of coolant switch did you use. I've noticed there are 2 listed one's a 92* and the other a 75*. I'm having an issue with my fans not kicking on and off at the proper times and just curious which one would be best since I have both. And hopefully I only have to do this once lol. Thanks for any info... peace, Johnny O.

Dan84944 · 01-08-2021, 05:43 PM

Quote:

Originally Posted by Johnny O

Hi Dan84944, what degree of coolant switch did you use. I've noticed there are 2 listed one's a 92* and the other a 75*. I'm having an issue with my fans not kicking on and off at the proper times and just curious which one would be best since I have both. And hopefully I only have to do this once lol. Thanks for any info... peace, Johnny O.

Personally I used what was on the car already. Once you get the switch out the temp rating is engraved on the top. It is important to match up the switch with the temp of your thermostat. If you choose a switch like the 92° one, but have a 77° thermostat, then the fans will kick on very late. If you have a 92° thermostat, but have a 77° switch, then the fans will kick on very often.

Johnny O · 01-08-2021, 10:13 PM

Quote:

Originally Posted by Dan84944

Personally I used what was on the car already. Once you get the switch out the temp rating is engraved on the top. It is important to match up the switch with the temp of your thermostat. If you choose a switch like the 92° one, but have a 77° thermostat, then the fans will kick on very late. If you have a 92° thermostat, but have a 77° switch, then the fans will kick on very often.

Thanks Dan, for the info, I greatly appreciate it...