taurus fan, diode part #

[DanWheeler]

BTW - I'm not happy with the results I get from the tapped thermostat housing. The temperature can vary wildly probably because of the thermostat opening/closing and maybe because the housing has so little mass/insulation.

For example, I was heading down a mountain pass the other day and my temp reading plummeted below 80 degrees. I know the engine wasn't running that cool but the thermostat housing was very cold and my temp gauge picked that up.

also if the thermostat got stuck in the closed position, it could possibly read a low temperature while the engine was overheating.

 

[Bronchole]

If you wanted to get suppertrick you could probably wire the alarm to sound when it is off AND when the temp is above the set thermostat point for the relay. That way you are only annoyed when you forgot to turn it back on

 

[EBCRAWLR]

sounds like we are all on the same page! ;D

an alarm is well needed... i had a cb wired into the "RUN" position of the key on, (temporary) so when we stopped for an obstacle. i turn the motor off, but back to key, run. when then the fan came on. and since i knew we were stopped for a while i said hey fan GO OFF so i could use the CB. well 10-15 mins later when we started going again, i just jumped in the truck and off we went... well it wasnt long and i was like whats that smell? (coolant) .. something isnt right here.. OH HEY DUMMY!! HAHA

 

[Steve83]

Dan
You're right - the problem with tapping the t'stat cover is that it places the sensor on the COLD side of the t'stat. All the sensors need to be on the HOT side, which includes the heater core loop. That's why EFIs put the ECT on the outlet to the heater core - it always has flow, and is always the hottest coolant in the system. I had to build my own outlet from copper sweat fittings, so I might add another bung for a hi-temp sensor for my fans.

 

[DanWheeler]

Dan
You're right - the problem with tapping the t'stat cover is that it places the sensor on the COLD side of the t'stat. All the sensors need to be on the HOT side, which includes the heater core loop. That's why EFIs put the ECT on the outlet to the heater core - it always has flow, and is always the hottest coolant in the system. I had to build my own outlet from copper sweat fittings, so I might add another bung for a hi-temp sensor for my fans.

At what point does it become ineffective to put multiple sensors in the ECT location? I'm assuming the further away you get from the intake manifold due to copper fittings, tees, nipples, etc., the less accurate your readings get? Do you have any pictures of what you built?

 

[Viperwolf1]

BTW - I'm not happy with the results I get from the tapped thermostat housing. The temperature can vary wildly probably because of the thermostat opening/closing and maybe because the housing has so little mass/insulation.

For example, I was heading down a mountain pass the other day and my temp reading plummeted below 80 degrees. I know the engine wasn't running that cool but the thermostat housing was very cold and my temp gauge picked that up.

also if the thermostat got stuck in the closed position, it could possibly read a low temperature while the engine was overheating.

That location may not work well for the gauge sender but it would be fine for a fan temp switch.

 

[Steve83]

At what point does it become ineffective to put multiple sensors in the ECT location? I'm assuming the further away you get from the intake manifold due to copper fittings, tees, nipples, etc., the less accurate your readings get?

Distance isn't really an issue - there isn't enough airflow or surface area on the fittings to dissipate a significant amount of heat from the fast-flowing coolant inside. It takes a real heat exchanger (like the heater core or radiator) with forced airflow to do that. But if you're worried about it, just wrap some insulation around it - a rag, plumbing pipe wrap, whatever.

Do you have any pictures of what you built?

Are you kidding? ;D

. .

 

[Bronchole]

The cool thing about this (as it applies to most of our Broncos) is that you can adjust the effectivness of the thermal sensor with the heat control valve. Its inversly sensitive also! In the summer when you run your heat valve fully closed (stops coolant flow thru the heater) you have no fresh/hot fluid running thru the thermal sensor.

I'll stick with haveing the thermal switch on the wrong side of the thermostat. Sure, it won't have very good sensitivity to turn on the fan if/when the thermostat fails to open, but I do not think ANY ammout of fan action is going to keep you from overheating at that point.

 

[Viperwolf1]

I'll stick with haveing the thermal switch on the wrong side of the thermostat. Sure, it won't have very good sensitivity to turn on the fan if/when the thermostat fails to open, but I do not think ANY ammout of fan action is going to keep you from overheating at that point.

Exactly. If the thermostat is already closed the fan isn't doing anything useful. It doesn't take long to cool static coolant in the radiator. You don't need the fan to turn on before the hot coolant is coming out of the engine.