els1958

I suppose so if:1) you had a very good knowledge of the box interior and 2) you knew exactly what was wrong. Also, it's tight quarters under there. I've removed the box twice now. It sounds a lot worse than it really is, and I can assure you, I'm no gear head.

I had to repair my heater blend door, thus requiring me to loosen and pull back the dash to remove HVAC box. After reassembly, my abs light is on. Chkd fuses, they're ok. Suggestions? thanks guys. - - - Updated - - - Well, just got back from a short drive and the light went off. Anything to be concerned about?

I'll check that tomorrow afternoon.. Should be close to 90°. Thank you. - - - Updated - - - Checked the line as you suggested. It was "beer can cold". But here's why I don't think the blend door is the culprit. One morning, After the truck had sat all night, I drove it to work using vent air only - no AC. I took temp of vent air. Then after the truck had warmed up to 190°+ for several minutes, I checked the vent air temp again. There was only a 2° increase. That tells me the blend door is not allowing any significant warm air into the vents. I'm headed to Florida next week. I sure would like to lower the temp a few degrees.

Since completing the heater core and evaporator install, I had the AC system recharged at a local shop. The tech told me the low side pressure is 30 psi. In 85° weather, I'm getting 55-60° air from the center vent w max-air and full fan. Quite frankly, I was warm. Before all this, my truck AC would freeze you out! I read the article at http://articles.mopar1973man.com/2nd-generation-24v-dodge-cummins/27-hvac-heating-ventalation-and-air-conditioning/58-recharging-air-conditioning-with-r134a-freon and noticed the performance temperature specs were exactly what I'm now getting. Is it unreasonable to expect my system to be as cold as it used to be? If its not unreasonable, what do I do to get my cold temps back? Although my blend door is stuck, I'm certain it is stuck in 'cold' position.

No critters, I just cleaned it all up when I installed heater core and evaporator. All vacuum operations seem fine. The blend door will not turn whether by motor or by hand. Hmmm, I forgot about that video I made. After reviewing it, I'm even more puzzled because everything seems to be properly located. The one thing I haven't done is try to push up on the door shaft. I'll try that and repost.

I recently rewired my gauges, and included a couple of these (see pic). Now if I ever need to remove gauge cluster for whatever reason, all I have to do is unplug. Of course, the boost line and pyro cable must be disconnected too. Just an idea if you change out some gauges.

After my heater core, evaporator, and dash cap install, the blend door would not work. It's stuck in the cooling position. I assumed it was a broken plastic piece at the bottom of the shaft, so I ordered a heatertreater part. Well, the plastic piece is fine. The door is unmovable. The blend door shaft is in position at top and bottom of hvac box - i can see that much. Anyway to rectify this without pulling out the hvac box again. It cost me $70 to have AC recharged and I'd like avoid that.Thanks,Eric

Ah ha! Michael, that gave me an idea. I went through the menu on the SG and there is an option that lets you choose whether to read MAP or boost. Even though it was on boost, I thought maybe it needed to be reset. I changed it to MAP, backed out of the menu, then changed it back to boost. It now appears to be reading actual boost. I think we all learned on this one!

Well now, that's within a few tenths of what the scan gauge is reporting. So, because the scan gauge is reporting the same boost value with XZT as it does without XZT, the boost fooler must not be working.

To borrow a phrase from Rossane Rosannadanna, "If its not one thing its another". My scan gauge is reporting 14 psi of boost at idle. The XZT is totally disconnected from MAP sensor. I recently installed heater core and had batteries disconnected for several days. Whats up with this?

Well, lets call this one done! Many thanks to dripley and mopar1973man for their help and advice. Each time I complete a job with the help of this forum, I make a donation the the Mopar1973Man website. I encourage others to do the same. Eric

You know, I carefully looked at those parts and decided mine was in good shape. I had the heater treater part, but the reindexing just seemed like more than I wanted to do. Apparently a big mistake on my part. Upon closer inspection, the blend motor is working, but barely turning the blend door shaft. Here's the good news. It's in the "cool" position, so I don't have to deal with this until fall :-).

Yes, I did reconnect the blend door motor. What's the fix for the blower? Is the resistor replaceable? Do I have to remove the hvac box again :-( thx

Everything is back together but I have two problems. 1). The blend door is not working, with heat temp turned all the way up, I only Get cool air. I know the little spring loaded door was reinstalled correctly, and the vacuum line that goes through the firewall is connected and working because all air is directed to proper vents and after disconnecting the vac line that goes through the firewall, only the defrost vents work. Which vac line control the blend door? Any ideas?2). My fan only works on highest speed.Thanks guys!Eric

Yes. It was on a divided hwy with very gentle (2-3%) rolling hills. I was using the cruise control.

I posted because this was "unusual" for my truck regardless of the type of driving. However, just to clarify, this varying temp was in town and on the highway at 60mph for over 15 minutes. Solo, not towing. I'm just going to get it all done late next week - heater core, evaporator, thermostat and water pump. I don't think the water pump has ever been replaced, so, while I've got the coolant down, I'll just go ahead and do that too. Towing season is just around the bend!

For the last couple of days, I've ran the AC. It is not draining. I put a vac on the drain, and still nothing. However, I've also had the carpet and rubber mat pulled back to dry, and during that time I've not seen any water in the floor board. I ran my car's AC for a while and it produced condensation drainage, so I know the humidity level is sufficient to produce significant condensation. None of this is making sense to me. Am I missing something?

Saw something unusual today. My temps are varying much more than normal. Usually temps stay between 190 and 195. Today, 181 - 200. The thermostat is only 3 months old. All temps are per my scan gauge. What's up with this?Thx,Eric

Alright, you guys have talked me into it. Some of you walked me through installing my rv275's last year, so I may lean on you a bit on this one too. One last question, is there anything else I should do while doing this heater core replacement?

I noticed that the rubber mat under the carpet was not wet. So I pulled it up. Wow, the under side of the rubber mat is soaked! I guess that means the leak is closer to the firewall. Does that change anything in my conclusion that the heater core is leaking and that's where my coolant has been going?thanks again!

I've noticed over the last few months that there has been a slight loss of coolant. I pulled back the carpet on the passenger side, and noticed the insulation under the carpet is damp. I'm concluding that the heater core is leaking. Here's my questions.1. If I wait until late summer or fall to repair this, and if I don't use the heater, will it continue to leak into the cab?2. I'm thinking this is a job that is too big for me. What should I expect to pay to have this fixed?Thanks to all who respond,Eric

I figure the hi-perf tune has an error. If I can find the tunes online somewhere, with descriptions, I'll change. I'm gonna reconnect the XZT and run it on econo mode and see what happens.

A couple of weeks ago, I was tool'n around town and realized my Quad XZT was on high performance setting. I switched back to the low setting which I run all of the time. However, shortly after switching down, the engine light came on. The code was P0237. Since then, I have hardly driven the truck. Today, I disconnected the Quad XZT and drove the truck to run some errands. After a few starts, the engine light went off, and when I checked codes, only the P1698(I think?) was displayed. Here's my take on this. The truck was never over 40mph when the XZT was switched to the hi setting. It was dumping fuel with very little boost, and the MAP sensor thought the boost was failing- thus the P0237. Make sense?Thanks guys,Eric

No, I've noticed nothing unusual at all.

Engine light came on. When I chkd code by turning key 3x, I got P0237. How do I clear the code so that after I disconnect the Quad module, I can see if that was the problem? If not the Quad, I assume its the MAP sensor. Anything else I should consider? By the way, where's the MAP sensor located?thx,Eric