74 Monaco Bro HVAC problems,

[dqdan]

Hi guys, Dan P from Ohio here. I recently brought home a low mileage 74 Monaco brogham hardtop, someday she may be a blumo but for now she makes a dandy hooptie in all her black over green glory.   I'm going thru the usual stuff making her 100% operational, and it seems the heater/def is a problem.  I've fixed brakes, wiper bushings, batt, bearings, etc..but the blower motor is dead.  The wires coming off the heat controls do NOT match the scematic for a 74 Monaco that I found online.  I've got 50% of the dash out trying to find the heat sink for the blower stepdown, but I can't find it.  A thick grey wire leaves my switch, but a green wire goes to the blower.  When you put 12v to the green blower line, a bunch of stinky debris hits you in the face so at least that part (blower) is good. The switch is getting juice.  The control unit has 6 buttons and a hot-cool slider wand and it says Auto Temp II on the controller.  This is where it gets interesting.  I found online an original (yellow paper) service (Master Technicians Service Conference, 14 pages) manual for Chrysler Auto-Temp II reference book 71/4. I think that means 71-74, but could be wrong.  I bought it for $20, hoping it would help me solve the problem. Well, it does not look to be from my car. The control they write about in this very complex book has a turning wheel for temp selection.  But, in the blower control section it mentions a valve that DOES NOT LET THE BLOWER OPERATE unless the hvac has 8 in of vac.  I did find a couple of nicked vac  lines near the antenna in the engine compartment, where I know I was losing some vac.  I have patched the vac lines but did not imagine they could contribute to disableing the blower due to a vac leak!!  I'm going to put it all back together and test it with less vac leaks, we'll see.  If that fails I think i'll have to jump it.

Anyway, is there anyone else out there in Blumo land that has had this problem? Should I just run a 15 amp switch to the green blower wire? I'd sure like it to stay original looking and operating.   Anyone want me to scan in a service manual for Chrysler Auto-Temp II systems? It might help some jake somewhere..


TKS

Dan P
74 Monaco B  Ohio

[Sd.Kfz. 400]

Shop manual: bluesmobiles.proboards.com/thread/816/1974-dodge-manuals-free-goodies

[sigmfsk]

Auto Temp II; you have the fancy version!
From the 1974 Dodge Operator's Manual:



I've never seen one of those. That's a kind offer to scan in the manual, but I'd suggest waiting and seeing if anyone requests it, as there may not be much call for it being that most Monacos (including the bluesmobile) had the standard control. I'm afraid I don't have any information on it or suggestions for repair. Along with the standard service manual, it looks like you have all the docs on it.

[dqdan]

THANK YOU THANK YOU THANK YOU!Thanks for the link to the manuals, and muchas gracias to the guy who put up the manuals. I may be able to work thru it with the tools at hand. I'm highly suspicious of the switch that shuts off everything unless the HVAC is receiving 8 inces of vac. This will be the first car I had that the blower would not run if there is a vac leak! I was hoping by buying a car from the mid 70 that the technology would be easy to work with, but some of these servo driven switches and such are a bit confusing. Oh well, I HAVE FACTORY MANUALS NOW!! I can fix anything!

Thanks again

Dan P
Cleveland OH
74 Monaco Broghm

[dqdan]

Sig, my control looks like the one you pictured. I read Auto Temp II on mine, then when I google searched and found that Chrysler service manual. Apparently, they call both our setup and the rolling wheel thing AutoTemp II. It cost me $20 to learn it, but it still gave me a good degree of insight to my issue. The only real difference it seems is our slide hot-cold selector (connected to a potentiometer, not a cable to a valve)is replaced with a rolling wheel attached to a potentiometer. I just ran a vac test at the canister and my 400 ci 2bbl is making near 20 inches of vac so that is not the problem.

Tks!

Dan P

[dqdan]

Well, if anyone out there in Blumo land is curious, I found a mouse/chipmunk nest blocking travel of one of the doors in the hvac, once the door was clear, the vac moved the door to the close position, therefore the rest of the system came alive when the actuator rod completed it's travel. Darn Rodents!

[sigmfsk]

Nov 13, 2013 23:25:40 GMT -5 dqdan said:

I found a mouse/chipmunk nest blocking travel of one of the doors in the hvac...

I guess that's probably not covered in the shop manual. Good job getting it working.

[Ghostbluesman (Ghostsoldier)]

I left that part out, when I uploaded those manuals. ;D

Glad you could use them, Dan...I'm here to share.

Rob

[Steam McQueen]

Nov 13, 2013 23:25:40 GMT -5 dqdan said:

Darn Rodents!

And sometimes it's a tree ...




Heh, that pic is from "Blusmbl's" build thread which is loaded with pictures!

- bluesmobiles.proboards.com/thread/616/blusmbls-blumo-restoration

I believe a banyan tree was the culprit in that one lol.