Cooling System - Have a Backup!!!

[Gumball]

I learned last night that having a back-up on your cooling system is a good idea. After 4400 miles of driving fun, I had a little hiccup last night while driving through town at low rpm and low speed. I'm very good about watching my gauges, but because of traffic I hadn't looked in a few minutes. I was surprised to see that my coolant gauge had moved from the usual 90 - 95C up to 105. Although I have a thermostatically controlled electric fan switch, I also installed a manual override switch. So, I quickly executed my planned emergency procedure and flipped on the manual, as well as sliding the heater temp out to full hot and turning on the blower motor to make my heater core into a temporary back-up radiator. The temp quickly settled back down to the acceptable range and I made it home with no issue.

A thermostatically controlled fan switch is a nice convenience, but if it fails, it's best to have a means of getting the fan running again - especially if you're in traffic. I highly recommend taking the time to wire in a redundant switch. Also, if you live in a colder climate, remember that a heater can serve the dual purpose of being a temporary radiator in the event you need some additional cooling - it's not just for extending the driving season.

Happy Ending: This morning, I checked the cooling system with an infra-thermometer and found that the thermostat in the engine was functioning fine - it is the thermostatically controlled fan switch that is intermittent. I'll get a new one installed ASAP, but probably one that is just an off-on so that I can avoid the issue of another rheostat going bad.

[dmoran]

Thanks for the benefit of your experience. I'll add that to my list.

[CraigS]

Yep, I used to have an adjustable setup w/ the probe between the radiator fins. Liked that because I could get it to come on whenever I wanted. New radiator w/ less gap in the fins and now a screw in sensor. But all I can find is 195 deg and my engine runs at 180 so it's 15 deg over normal before the fan comes on. I realize 195 won't actually hurt it but I don't like it. I have gotten so that nearly anything other than interstate I just flip the switch on and leave it. I like that is stays at 180 no matter what.

[rmiller64]

I installed a twin pusher fan setup more for appearance but has a dash toggle through a rely to make functional. Now I feel more comfortable having that backup system. The Fans Move a lot of air.

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[Larry Johnson]

I like the look of your fans as well.
Where did you get yours? I haven't seen them from all the usual suspects.
I live in Texas and we need all the cooling help we can get when it is over 100 degrees out.

[carlewms]

I have a Ron Davis radiator I purchased from Gordon Levy ... big radiator with 2 built in shrouded fans ... The EFI system controls the fans in automatic mode and I can turn on the manual switch hooked up to one of the fans on the radiator.

Even though I have not got on the road yet during testing the auto system was not working and it was nice to flip on the manual switch and cool the engine down.

Carl

[UnhipPopano]

As "Switch" has been used a few times, and best guess is that a mechanical switch is being used, the switch is trying to maintain 180 degrees and has a 15 degree dead band. this means that on a cold day the fan will stop when the temperature reaches 180 degrees.

[rmiller64]

I like the look of your fans as well.
Where did you get yours? I haven't seen them from all the usual suspects.
I live in Texas and we need all the cooling help we can get when it is over 100 degrees out.

Larry, The motors and Fan blades were purchased through Grainger online. I fab the mounting bracket myself and powder coated. PM if you need the part#'s and I'll hunt down the packing list