I have used two different forms of electric/aftermarket fan control switches and switch mounting designs. I figured I would give a listing of some new switches I found in hopes that they might make life easier for some people.
I had been using a Horton fan switch for fan control on a semi/big rig air fan control system on cars I'd built. These switches can be had in 190,195,200, and 205 degree cut on points and are available in N/O or N/C or Both configurations, but they require a 1/2 " npt hole to mount them. I have modded the t-stat housings to accept these and built stainless 1 1/4" top radiator hoses to carry these switches. They make these switches in a 3/8 " thread but they are 100.00 to 135.00 where as the 1/2 " npt switches are 40.00 to 50.00. Summit sells fan control switches but they are about 60.00 a kit and require a 3/8 " npt hole (something that is not on the 7m stock). You can tap out the existing 3/8 " bpt hole but they sometimes will leak do to a thread overlap from the metric tapping to the standard tapping. This can usually be fixed by using good thread sealant or even RTV Black or Gray sealant.
All of this lead to looking for a plug n play switch for modified cars such as people going to FFI's or not using their CSI anymore. Napa sell two switches an FS140 that turns the fan on at 182 to 189 degrees (25.00) and an FS132 that turns the fan on at 194 to 202 degrees (35.00). These two switches have 16 by 1.5 mm threads and will screw directly into the CSI thermo time switch port on top of the engine side t stat housing and they are normally open switches(N/O).
I wire these switches to control the primary or trigger circuit of a relay with a driver emergency override switch in case of a coolant switch failure. I have been running the Horton switches for 5 years and never had a failure and my fans cut on at 190 and off at 178 to 182 even on upper 90 degree days. The owner of the car I'm building now and I have decided to try the cooler of the two switches on his upgraded automatic car and see how it works. I'll keep you posted.
Sean
I had been using a Horton fan switch for fan control on a semi/big rig air fan control system on cars I'd built. These switches can be had in 190,195,200, and 205 degree cut on points and are available in N/O or N/C or Both configurations, but they require a 1/2 " npt hole to mount them. I have modded the t-stat housings to accept these and built stainless 1 1/4" top radiator hoses to carry these switches. They make these switches in a 3/8 " thread but they are 100.00 to 135.00 where as the 1/2 " npt switches are 40.00 to 50.00. Summit sells fan control switches but they are about 60.00 a kit and require a 3/8 " npt hole (something that is not on the 7m stock). You can tap out the existing 3/8 " bpt hole but they sometimes will leak do to a thread overlap from the metric tapping to the standard tapping. This can usually be fixed by using good thread sealant or even RTV Black or Gray sealant.
All of this lead to looking for a plug n play switch for modified cars such as people going to FFI's or not using their CSI anymore. Napa sell two switches an FS140 that turns the fan on at 182 to 189 degrees (25.00) and an FS132 that turns the fan on at 194 to 202 degrees (35.00). These two switches have 16 by 1.5 mm threads and will screw directly into the CSI thermo time switch port on top of the engine side t stat housing and they are normally open switches(N/O).
I wire these switches to control the primary or trigger circuit of a relay with a driver emergency override switch in case of a coolant switch failure. I have been running the Horton switches for 5 years and never had a failure and my fans cut on at 190 and off at 178 to 182 even on upper 90 degree days. The owner of the car I'm building now and I have decided to try the cooler of the two switches on his upgraded automatic car and see how it works. I'll keep you posted.
Sean
