When I drive up hill on the highway or accel at the greenlight, my heated air suddenly diverts from frontal to windshield defrost/fog. As soon as I let upon the gas or reach the bottom of the hill it goes back to normal.

I have a 98 1500 Ram with 5.2L engine. My neighbor laughedat the truck because I had trouble hauling a 8x30 travel trailer. He has a 6 cylinder Dakota that hauls a larger trailer than the one I just got. Okay, so my engine bellowed out smoke while trying to back it into the driveway, but I did manage to drive it 3 hours from Charlotte to here! Yeah, every hill I hit I was doing 55 in fourth gear and doing 40 in third gearby the time I reached the top! Little ol ladies driving Buicks were giving me thefinger as they passed me by - OUCH!

After 100k, I just replaced the thermostat and waterpump cause they blew on New Years Eve. BTW- thanks to this site for having the instructions for doing so!!!!!!!! I need to donate some of my savings to the folks that are saving my poor *** some money!

So what could be my problem with the air thing?

Thanks in advance!

Stuart

 

My Grandpa used to have one of those old AWD Eagle station wagons and it did that same thing. Had something to do with a vacuum line, but I can't remember exactly what it was...

 

there are a couple of small check valves in the vac lines. one is close to intake on passenger side. other is close to firewall on passenger side. they are small about the size of a quarter. do a search here for lots of previous posts.

 

this may be the common
"Wild Vents"
problem

https://dodgeforum.com/m_868975/tm.htm

from the way the truck is behaving on the hills
consider checking your catalytic converter for partial plugging

Check with the dealership to see if your truck is eligible for a free catalytic converter under the terms of the big recall for 1996-1999 Rams:

http://www.arb.ca.gov/newsrel/nr122105.htm

http://epa.gov/compliance/resources/...ler-fcsht.html

 

I've had this happen to me twice. The first time was the plastic vacuum line going to the cruise control (which is under the battery) - my cruise control wouldn't work. Find the vacuum line going from the passenger side of the intake manifold to the cruise control and disconnect it from the main vacuum line (it "T's into it) and put a golf tee in the place of where the cruise control line was. Then drive it. Does this solve the problem? If so, then it is somewhere along the cruise control vacuum circuit. I had to replace part of thehard plastic vacuum line with rubber hose under the battery.If this doesn't solve your problem, reconnect yourcruise control vacuum line back up since the problem isn't there. The next time this happened to me, it was one of the vacuum check valves. There are two; one right near the passenger side of the intake manifold, and one between the intake and air conditioning condenser. The part number at the dodge dealer is 4549209 @ $6.05 each. Took me less than 5 minutes to replace both, and problem solved (again). Hope this helps.