AC stuck on defrost

[dripley]

i got my ac working again the other day but the controls are stuck in the defrost mode. I know the controls need vacuum to operate and all my other accessories work, 4wd and the exhaust brake. I have vacuum where the line goes thru the firewall at the evaporator. A good while back when I replaced the evaporator I noticed the hard line going thru the fire wall had cracked and I replaced a section with vacuum hose and have vacuum to that point. I figure while installing the new drier or high pressure line I most likely fractured the hard line going thru the fire wall. Does this hard line go straight to the multi point connector for the controls?  I could not quite contort myself enough to check for vacuum at that point. My thought is just to run some new line thru the firewall and to that connector. It seems to me that should work as long as that line is not connected to something else before the multi point connector. 

[TFaoro]

Is it leaking vacuum? Suck on it and see if it's holding like it's supposed to

[Haggar]

Drip,

Here is the page from the FSM.   You should be able to check where you are losing the vacuum down at the multi-tube connector.  The mode knob on the instrument panel actually changes vacuum paths. (as best as I can tell....  I know GM does this, I am going totally on the fsm and can't prove the dodge does.)

 

Hope this helps.

2001 FSM Ram 24-12.pdf

[dripley]

48 minutes ago, TFaoro said:

Is it leaking vacuum? Suck on it and see if it's holding like it's supposed to

I did not think to suck on the line. Something about that dont sound right. I does however sound like a decent way to see if is a leak. Have to get some more hose, no way my punkin head will get in there. Does the vacuum pump produce enough vacuum to run every thing when the line to one accessory broken?

 

49 minutes ago, Haggar said:

Drip,

Here is the page from the FSM.   You should be able to check where you are losing the vacuum down at the multi-tube connector.  The mode knob on the instrument panel actually changes vacuum paths. (as best as I can tell....  I know GM does this, I am going totally on the fsm and can't prove the dodge does.)

 

Hope this helps.

2001 FSM Ram 24-12.pdf

I have looked at that page but never could find a schematic or drawing showing the routing of the vacuum lines. Connection 3 shows this being the vacuum source. Just not sure if this line feeds any thing else before it gets to the connector. It would appear to me that it operates as you are thinking.

[TFaoro]

1 hour ago, dripley said:

I did not think to suck on the line. Something about that dont sound right. I does however sound like a decent way to see if is a leak. Have to get some more hose, no way my punkin head will get in there. Does the vacuum pump produce enough vacuum to run every thing when the line to one accessory broken?

You should be able to pop the line off and pull it out. I can't get my big head in there either!

I think it'll run some things, but it just depends on how big the break is.

[dripley]

1 hour ago, TFaoro said:

You should be able to pop the line off and pull it out. I can't get my big head in there either!

I think it'll run some things, but it just depends on how big the break is.

There is no slack to pull. If there was I used it up when it broke during the the dash install. I dont know what else that line could run. There is another on the drivers side that runs down toward the tranny/transfer case which I am assuming runs the CAD. It just seems strange that they would run the the vacuum all the way across the fire wall then thru the firewall and back across to the HVAC controls.

[TFaoro]

They didn't want another hole in the firewall... Ran it by the AC / heater hoses. At least that's my guess!

 

You should be able to literally take the line out and hold it over by the ABS module. At least that's what I did.

[dripley]

I have no slack coming out of the firewall. Unless I disconnect it from the multi point connector and try and pull it them. It does run along the cowl with the big wiring harnesses almost from the ABS module. The little manifold it ties into is right there near the connectors for those harnesses.

 

Looking at @Mopar1973Man HVAC box removal article I can see the vacuum line running along the back of the box with the green tube for the outside air actuator. It does not appear to be connected to anything but the multi point connector. Now if I can just contort myself enough I will unplug it and see if there is any vacuum there. If not I will just try and fish another line in there. If this old one broke twice, I think I need to be shod of it.

[Mopar1973Man]

Green line is a vent vacuum. Black line should vacuum source. I font remember the rest.

[dripley]

7 minutes ago, Mopar1973Man said:

Green line is a vent vacuum. Black line should vacuum source. I font remember the rest.

I knew what the black a green were, you can see them with the glove box out. The green goes the the actuator on the vent at right end. It looked green to me any way. 

 

But now here is the rub. I stopped at Auto Zone 15 minutes ago and picked up some vacuum hose and tubing. I took the hose outside to be sure it was the right size. Disconnected the line and the hose was the right size. So went back in, paid for it and got in the truck. Fired it off and low and behold I have cold air blowing on my face. Dont know what I did, I have had that joint apart 3 or 4 times with no difference but now it works. Sitting here idleing with 42* blowing in my face.

 

On another note, while scoping things out I found my passenger floor board swimming in water today. Climbed under the truck thinking the drain is clogged. Rammed some wire in there and nothing. Pulled the carpet back and nothing was wet 2 or 3 inches above the floor. Is there supposed to be a fitting on the end of the drain tube? It almost looks like the water coming out is being directed back in to the cab around the outside of the drain tube. It is just facing forward into the wind. When the truck is sitting still there is a lot of water coming out of it.

[Buzzinhalfdozen]

@dripley yes mine has a rubber 90* elbow on the ac drain. It hangs down about an inch. 

[dripley]

1 minute ago, Buzzinhalfdozen said:

@dripley yes mine has a rubber 90* elbow on the ac drain. It hangs down about an inch. 

Thanks. I bought some tubing to put a piece on and see if that will get it going down. Probably did not put it back on after fixing the HVAC box.

[Dieselfuture]

I had same thing happened with my ac drain, it came back in the cab, I put a clear hose on a drain nippel and zip tide it to some hoses or a brake lines by control arm, itso crazy home much water comes out of it.

[dripley]

4 minutes ago, Dieselfuture said:

I had same thing happened with my ac drain, it came back in the cab, I put a clear hose on a drain nippel and zip tide it to some hoses or a brake lines by control arm, itso crazy home much water comes out of it.

Your not kidding about the water. I vacuumed out all that i could last night, not dry but no standing water. Drove 15 miles to Sunbelt rentals and the carpet was full again with some water on top of it. Got a hose on it now we sill see how it works.

[Haggar]

drip,

Our humidity is terrible right now!   you will probably make a quart an hour or more condensate.  Glad you got it worked out!

 

The gassers, have a vacuum reservoir under the cowl, and the black line going to the HVAC comes from a tee there.  I don't think the diesels have that reservoir, but not certain. 

 

pick up a little hand powered vacuum pump.  I have one in a box with a bunch of adapters, so I can troubleshoot problems like this.  GM TDs have lots of trouble with the wastegate actuator system...  I end up testing them a bunch....

 

Hag

[dripley]

Not sure where you are but I am in Richmond VA right now and the humidity was 85% yesterday and near 75% now. She is spitting the water out.