Understanding Auxiliary Fan on '79
03-14-2023, 09:29 PM
#1
Rennlist Member
Thread Starter
Understanding Auxiliary Fan on '79
I've been trying to figure out the aux fan as I've been looking into the a/c. As I understand it, it can be activated a few different ways. The engine has a new temp switch (below the water bridge) along with a new engine wiring harness. I jumped the relay and the fan came on. I also jumped the wires by the dryer and it came on. Does this signal a bad relay? The condenser is not hooked up. Last summer I can remember the fan kicking on but now it does not. The reason I am asking is that when I let it idle for a while trying to troubleshoot something the water temp gauge has climbed (maybe right around 3/4). I can shoot the IR gun next time I have it idling for a while, probably tomorrow. What temperature should I be shooting for and what temp is considered the bottom range of "too high"?
03-14-2023, 11:32 PM
#2
Rennlist Member
The switch below the water bridge is for the cold start injector. Otherwise known as the thermotime switch.
The switch that controls the fan is actually at the base of the radiator on the driver's side (lhd).
They're inexpensive, but a bit annoying to replace. Get an OEM one for like $20 and replace it every 10 years or so. Or with every timing belt.
The other way it activates is a temp switch that goes into the metal of the receiver drier. It doesn't actually go into the refrigerant so you can replace it any time if it ever goes bad.
The switch that controls the fan is actually at the base of the radiator on the driver's side (lhd).
They're inexpensive, but a bit annoying to replace. Get an OEM one for like $20 and replace it every 10 years or so. Or with every timing belt.
The other way it activates is a temp switch that goes into the metal of the receiver drier. It doesn't actually go into the refrigerant so you can replace it any time if it ever goes bad.
03-15-2023, 12:07 AM
#3
Rennlist Member
Thread Starter
The switch below the water bridge is for the cold start injector. Otherwise known as the thermotime switch.
The switch that controls the fan is actually at the base of the radiator on the driver's side (lhd).
They're inexpensive, but a bit annoying to replace. Get an OEM one for like $20 and replace it every 10 years or so. Or with every timing belt.
The other way it activates is a temp switch that goes into the metal of the receiver drier. It doesn't actually go into the refrigerant so you can replace it any time if it ever goes bad.
The switch that controls the fan is actually at the base of the radiator on the driver's side (lhd).
They're inexpensive, but a bit annoying to replace. Get an OEM one for like $20 and replace it every 10 years or so. Or with every timing belt.
The other way it activates is a temp switch that goes into the metal of the receiver drier. It doesn't actually go into the refrigerant so you can replace it any time if it ever goes bad.
03-15-2023, 12:16 AM
#4
Team Owner
yes the coolant will drain out