High Temp *** Again *** All about the fans please
Thread Starter
Instructor
Joined: Dec 2001
Posts: 147
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From: Riverside CA
High Temp *** Again *** All about the fans please
Help... I understand why GM runs the L-98 so hot, but I can't figure out the main and aux fans. What turns the Aux fan (in front of the radiator/ac) on and at what temp. ? I am in the process of replacing the regular relay and fan motor, I found the relay connection fried and may need to rewire. At what temp should the regular radior fan come on. Is trying both fans together a well thought out plan, any problems. Thanks for the help :seeya :seeya
Team Owner
Joined: Sep 2001
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From: Athens AL
C7 of the Year - Unmodified Finalist 2021
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Re: High Temp *** Again *** All about the fans please (myblack864+3)
If i remember correctly, the main fan comes on at 225 and the aux at 235
Racer
Joined: Apr 2002
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From: BAY AREA CALI
Re: High Temp *** Again *** All about the fans please (vader86)
What is a general accepted temp. My 95 runs about 188-193 avg except in stop and go lately it climbs to about 210-215. I've checked the front of the radiator and its clear except for one leaf. Also has anyone used Pro Blend additive it says its lowers temp up to 40 degrees?
Le Mans Master
Joined: Dec 1999
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From: And on the fifth day, subpoenas were served to Obama senior staff
Re:
Aux fan in front of the condenser is controlled by a coolant temp switch which is mounted in the drivers side head in between #1 and #3 cylinders. This switch (which looks like a coolant temp sensor) provides ground to the aux fan relay, which in 89 is mounted on the fan shroud. It will come on some where over 220* and perhaps over 230*, this varied by year.
Main fan is controlled by the ECM. ECM will ground the main fan relay located near the master cylinder. This will come on somewhere around the mid 220*, or when AC is operating. ECM will shut off this fan when vehicle speed exceeds about 35 mph.
You can buy a replacement aux fan switch to ground at a lower temperature; some folks will wire this aux fan switch to the main fan relay as well to turn it on. Downside is main fan will run when car is moving - this can cause wear on the fan and may decrease cooling at speed.
Some folks install a switch to ground the main fan relay, providing manual control of the fan.
I have a lower temp aux fan switch and a prom burned for the ecm to lower the on temp of the main fan. Works great.
Pete
Main fan is controlled by the ECM. ECM will ground the main fan relay located near the master cylinder. This will come on somewhere around the mid 220*, or when AC is operating. ECM will shut off this fan when vehicle speed exceeds about 35 mph.
You can buy a replacement aux fan switch to ground at a lower temperature; some folks will wire this aux fan switch to the main fan relay as well to turn it on. Downside is main fan will run when car is moving - this can cause wear on the fan and may decrease cooling at speed.
Some folks install a switch to ground the main fan relay, providing manual control of the fan.
I have a lower temp aux fan switch and a prom burned for the ecm to lower the on temp of the main fan. Works great.
Pete
Le Mans Master
Joined: Dec 1999
Posts: 8,540
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From: And on the fifth day, subpoenas were served to Obama senior staff
Re: (ZELLSLIFE)
Also has anyone used Pro Blend additive it says its lowers temp up to 40 degrees?
Used in regular AF/water mix the improvement is marginal, if any. AF already contains these wetting agents and corrosion inhibitors, so different ones - more does not improve the properties of the coolant in a major way.
You can run 40% Green AF and 60% water in most circumstances if you keep the system flushed, and this provides some improvement in cooling due to the higher percentage of water.
