Radiator Fans not engaging

[Sand blister]

Good afternoon everyone,

I have been having an issue with the car running warm. Replaced both radiator fans and 4 relays.

When turning the AC on the fans activate. I can also activate low and high speed with my durometric tool. However, the fans do not engage when the temp rises. No other codes present. Thermostat and water pump have about 5k miles on them.

Car runs fine while high way cruising.

Anything else I should be looking at?

[ike84]

How warm is "running warm"? Temp gauge blinking? Oil temps rising?

Sent from my SM-G970U1 using Tapatalk

[blue62]

Your radiator fans will no kick on until the coolant temp reaches 206.2 degrees-F
That will be low speed.
At 215.6 degrees-F high speed will kick in.
Dash temp. gauges are sometimes not very accurate.
So you could check fan function and accuracy of your dash gauge by hooking up your Durametric and watch the coolant temp. while the car is idling. That way your seeing the same temp. the DME/ECU is seeing.
Let the temp. get up to 206-208 and see if the low speed fan function triggers.
This will also allow you to compare the coolant temp. your DME/ECU sees to what your dash temp. gauge shows.

[Stl-986]

turning on the AC should also activate the fans or if you have a durametric you can turn them on there as well.

fans are common failures though. Fans will fail before the relays for them will.

[Smallblock454]

Did you check the resistors for the radiator fans?

What temperature is the thermostat specified for?

[Seal1968]

The resistors are prone to failure...fans are new, relays are new.

Their location makes them vulnerable to splashes, and they tend to corrode, crack.

You can easily replace them with after-market, rather than paying P-car prices...search this site, I did this. Very easy.

[Sand blister]

So update here. Plugged in the the durametric tool once again to do a live read. Fans came on at 210 for low speed. Just for reference, 210 on the durametric is dead center on 0 in the 180 on dash.

So once again, what I thought is running warm is likely totally normal.

Did a hard day of driving in the Catskills today with a group. My constant read when driving hard was between 205-220

New fans, new relays. Water pump and low temp stat have about 7k miles on them.

Thanks everyone for a great discussion.

[blue62]

Originally Posted by Sand blister

So update here. Plugged in the the durametric tool once again to do a live read. Fans came on at 210 for low speed. Just for reference, 210 on the durametric is dead center on 0 in the 180 on dash.

So once again, what I thought is running warm is likely totally normal.

Did a hard day of driving in the Catskills today with a group. My constant read when driving hard was between 205-220

New fans, new relays. Water pump and low temp stat have about 7k miles on them.

Thanks everyone for a great discussion.

From what your reporting it sounds like your coolant temps. and fan operation are perfectly normal.

[Seal1968]

Good to hear sir...this is what I like about this site.