AC Question

[Bill W]

Driving along with the AC on and I downshift to pass a truck. AC air starts blowing hot for a few seconds. Let off the throttle and all is well again. Happened twice in two days. Never before. Anyone have an idea why?

[Steve-Indy]

Common, built in...A/C shuts down on heavy acceleration.

[Old School]

My Gen3 does this on anything other than very modest acceleration. I remember Chrysler cop cars back in the '70s having the AC cutoff switch, on the dash, within easy reach.

[Bill W]

Thanks Steve. Good to know.

[Crimson135]

You can put a check valve in the vacuum supply line. Local parts store should have one for less than $10.

[Fatboy 18]

Look under Radiators on the Viper Store website.
Ipsco used to list a device that stops the AC from shutting off under hard acceleration.
I can't see it on Marks current web page but the Viper store shows a pic of it.
Perhaps now a discontinued part?

Or Dave bought them all up

[dave6666]

Wait wut?

[Fatboy 18]

Hey Bill, if this is the first time you have noticed this , then clearly you are not driving the car hard enough

[Bill W]

Point taken. Will attempt remedy ASAP. :

[daveg]

valve.jpg
Mcmaster.com
High Temp Valve #47245K26
High Temp Hose, #51135K172, $.81/ft (need 1.25")

[Bill W]

Thanks daveg

[dave6666]

...

At $15 versus $200 i.e. 87% cheaper, someone can't be too happy that you've discovered this alternate magic.

[Crimson135]

At $15 versus $200 i.e. 87% cheaper, someone can't be too happy that you've discovered this alternate magic.

It's ridiculous how expensive viper ownership can be... I understand they are a pretty small niche market, but damn.

[Bill W]

valve.jpg
Mcmaster.com
High Temp Valve #47245K26
High Temp Hose, #51135K172, $.81/ft (need 1.25")

McMaster only has the hose in 10' lengths. NAPA and Advance Auto don't have anything close. Anyone have a small piece they could sell? It's advertised as High-Temperature Silicone Rubber Tubing, Opaque Black, Durometer 70A, 3/16" ID, 5/16" OD

[jdeft1]

Or.... just leave it alone and know the air on these cars will drop out on hard acceleration. Normal.

[Matt M, Pa]

C'mon guys...the A/C doesn't shut off under acceleration...the vacuum drop merely directs the air to the defrost vents. Which is why those check valves can fix the issue.

Even if the A/C were to shut off under WOT...it won't immediately get hot. Just as the heater core doesn't get cold as soon as you shut the car off.

[98RedGTS]

McMaster only has the hose in 10' lengths. NAPA and Advance Auto don't have anything close. Anyone have a small piece they could sell? It's advertised as High-Temperature Silicone Rubber Tubing, Opaque Black, Durometer 70A, 3/16" ID, 5/16" OD

They don't have 3/16ID Vacuum tube? That's surprising as it's not that uncommon of a size.

[Bill W]

Installed the check valve last week as shown. Took the Viper for a run, and at WOT with AC on, cold air continued to flow from the dash vents uninterrupted, whereas hot air gushed from the same vents previously. I didn't check the defrost vents to see if additional air was directed to them. Simple fix that works for me.

IMG_0446.jpg

[daveg]

Installed the check valve last week as shown. Took the Viper for a run, and at WOT with AC on, cold air continued to flow from the dash vents uninterrupted, whereas hot air gushed from the same vents previously. I didn't check the defrost vents to see if additional air was directed to them. Simple fix that works for me.

IMG_0446.jpg

Glad you found the hose and it worked out for you!