ZR-1 Net Registry Forums - View Single Post

secondchance · 08-02-2021

Yes. High pressure switch screws onto Schrade valve. However, at least in my case, Schrader valve is in stuck open position. Also, high pressure switch is tough to find for later cars 93 to 95.
I didn?t want to pay $400 for refrigerant evacuation and refill to replace the valve. So, I spliced in a toggle switch so that I can manually turn on the fan (in traffic) when engine temp is too low to turn on the fan. And turn off the fan at highway speed since speed will keep the air flow across the condenser.
Fans are dependent on engine temp and refrigerant pressure to turn on. For primary and secondary fan strategy, refer to shop manual.
I think for 91, part number is acdelco15-2352.

Glad I could help!

08-02-2021	#4
secondchance Join Date: Aug 2006 Location: McLean, VA Posts: 3,730	Re: A/C Engine cooling fan switch question Yes. High pressure switch screws onto Schrade valve. However, at least in my case, Schrader valve is in stuck open position. Also, high pressure switch is tough to find for later cars 93 to 95. I didn?t want to pay $400 for refrigerant evacuation and refill to replace the valve. So, I spliced in a toggle switch so that I can manually turn on the fan (in traffic) when engine temp is too low to turn on the fan. And turn off the fan at highway speed since speed will keep the air flow across the condenser. Fans are dependent on engine temp and refrigerant pressure to turn on. For primary and secondary fan strategy, refer to shop manual. I think for 91, part number is acdelco15-2352. Glad I could help! Last edited by secondchance; 08-02-2021 at 06:51 PM.