Traffic light insurance

[TX82FIAT]

Folks, I know some of the purist will not like this modification. I wired a radiator fan override switch in parallel with the existing circuit so it will still turn on and off based on temperature. Cost $10 for toggle and a slightly higher gauge wire and took about 25 minutes once master cylinder was moved to the side for wire through the firewall. For the record, I have a properly burped and functioning cooling system. the T-Stat opens when it is supposed to and the fan kicks on at about 194. No hole drilled in my T-Stat and I have the T fill plug at the high point of the engine making things easy.

However, even with all of that, I don't like the rapid heating and cooling of the system given the current design. Marks electronic water pump is an option I am considering. In Texas summer you will be cruising along at 70 on the highway, exit on to an access road and sit at a light five minutes. The car was just working hard so now the temp will rise and cool quickly. Why wait the extra two minutes for the car to get up to 194 +- degrees for the fan to kick on. The car is already operating at 185 to 188 normal running term and you know it will get to +- 197 before starting to cool down while stopped. My point being this. If you know the car will heat up and the fan will eventually kick on, why not flip the fan on as soon as you hit stop and go traffic. This is my third spider and like most of you, I watch the temp gauge religiously in stop and go traffic. So why not, why not reduce some of the temperature flux and maybe in the long run save a head gasket.

[81SPIDERMATT]

i have a manual switch also ... I upgraded to marks aluminum radiator (mine was toast) .... after the switch I watched the temp gauge a lot less after a while ... but in stop and go traffic I noticed that I was staring at it more ... now I just flip the switch in the summer in stop and go stuff .... it will hold 185 190 all day long .... I like the switch and use it often .. definitely makes for less watching the gauge for me

[azruss]

I put a manual fan switch in my 2L-fi. I live in the Arizona blast furnace and have never used the switch. When the system is air tight with a good radiator and water pump, it will handle 110+ heat without heating up any more than 10 degrees above normal.

[TX82FIAT]

Out for a long run this weekend in the Spider with my son after a cars and coffee event in San Antonio. After existing the highway we came up on a familiar light where we would sit for a few minutes. I flipped the fan on as soon as we stopped. Temp never rose above +-192. Normally it would have gone up to about 200 with the fan kicking on around 194. While I don't believe I need the switch, I do like the ability to proactively manage some of the heat.

[Turbofiat124]

It seems the cooling fan kicking on when it's supposed to has been my #1 problem with my Spider. Years ago it was going through a fan switch every year until I added a relay. And now use the fan switch to ground the relay.

I ended up installing one of those 185F fan switches but I found in the summer time, the fan tends to run most of the time and won't kick off for a couple of minutes after shutting the engine off.

A couple of other ideas that have come to mind.

Mount a fan switch in the cylinder head where the overheat switch goes. The only issue there is if the engine runs low on coolant it won't trip the switch.

The other idea is to use one of those devices that trips at a certain RPM. So at red lights, anything below 1200, the fan kicks on like a mechanical fan.

My 68 Ford has a mechanical fan bolted directly to the water pump. Some models had fan clutches but I'm not sure why Ford just didn't install them on all their engines. That car will idle all day long at 200 F no matter how hot it is.