I'm in the process of redoing the interior of my 460 powered (512 now - grin) 74 Montego and during the dash pad replacement I noticed a few additional 'behind the dash' issues that I'm interested in tackling that I think require a full dash 'tear-out'.
The vent ducts for the defrosters essentially disintegrated at the outlet (feeds the slots pointing to the windshield). Upon attempting to remove them, I noticed that they seemed to be assembled on the dash, then the dash to the firewall. I was able to get the vent ducts out - they were trash anyway, so wrestled them out, but assuming the replacement units won't go in as easily.
I also removed the inst. cluster (got a new clear face to install), and noticed some of the vacuum lines for the climate control system were very dry-rotted. They too, looked like they were installed in the dash prior to installation into the car. Since the car has been sitting for awhile, with the cluster, defrost ducts, and dash tray and pad removed, I figured I'd check out the function of the vacuum controlled baffles and blower while I could see them.
Note: This car originally came with AC (assuming controls may change the removal procedure) But, the AC was removed (engine side of the works) and a firewall 'coverplate' was installed that still allows the 'flapper' on the firewall to function - didn't want to block the function because I didn't know if I needed to lock it open or closed, so left it functional per the controls.
Fired up the car, and slid the first selector to cold, and put the blower on high, then cycled through the AC / Vent / Defrost control looking at the vacuum actuators. Noticed the great 'Smoke God' being released from the selector / control unit, so quickly dropped the blower down to low, and the AC control to off. Smoke stopped. Assuming the blower motor is frozen (but the squirrel cage spun freely prior to putting on the firewall (engine side) cover) and is causing the high current condition at the switch.
So, bottom line, looks like I need to 'get at' the blower motor, vacuum lines, ducts, and hell, while I have it apart, may want to pull out the heater core to get it pressure tested (or replace it) as I hear it comes out from the passenger side. All this makes me think the dash should come out so a proper 'rebuild' can be accomplished to the systems on the back-side of the dash.
Why all the fuss on a 74 Montego? turning it into a hot rod. So far looks great from all angles except the interior - the last step in the process. So, I'm hoping some of you in the NG can steer me the right direction. Got any ideas on how to go about tackling my issues??
Ben