I have a 1999 DODGE RAM 2500 v10 Quid Cad short bed
The A/C works great when I works
When I slow down or come to a stop it sound like a door closes under the dask it goes from cold air to HOT I have to turn it off and turn it back on after a few secondes it not the door under the glove box that's for inside air or outside air this mush I have found out
It is a vaclumm I think but I can not fine this second door does any one know
1 where this door is
2 where the vaclumis for it.
I have even gone to Dodge and they don't know or won't tell me unless they do the work
That is $85.00 a hour and I can afford that.
Love the truck just hate it in the summer when its 110 outside
Thank You
Ken

Sounds like it may be a vacuum hose leak. See if this link helps:

https://www.askmehelpdesk.com/cars-trucks/faq-how-troubleshoot-repair-maintain-hondas-selected-other-vehicles-46563-9.html#post1701268

If the evaporator coils are freezing up, the air flow will stop. Look for excess water and any freezing on the low pressure hose running from the evaporator coil to the accumulator. In this situation, the fix is simply to replace the A/C Clutch Cycling Switch. There's a shrader-type valve, usually located on top of the accumulator, that simply screws off. No need to worry about freon recovery--very little freon will escape. Coat shrader-type valve with refrigerant oil and screw the new A/C Clutch Cycling Switch on and reattach the 2-pin connector.

Sounds like it may be a vacuum hose leak. See if this link helps:

https://www.askmehelpdesk.com/cars-trucks/faq-how-troubleshoot-repair-maintain-hondas-selected-other-vehicles-46563-9.html#post1701268

If the evaporator coils are freezing up, the air flow will stop. Look for excess water and any freezing on the low pressure hose running from the evaporator coil to the accumulator. In this situation, the fix is simply to replace the A/C Clutch Cycling Switch. There's a shrader-type valve, usually located on top of the accumulator, that simply screws off. No need to worry about freon recovery--very little freon will escape. Coat shrader-type valve with refrigerant oil and screw the new A/C Clutch Cycling Switch on and reattach the 2-pin connector.

I have replace this value for the hi and low perssure
where is the line that go to this door on the inside I have look but can't find it
do you have any layout I can look up to see where these line run??

Sorry, I'm not familiar with your truck.