1975 blower housing differences

[Roblaw]

Took my fan housing off to get to the heater **** and found the housing all rusted out at the fresh air intake and flap. Looked at some on Fleabay and found some that looked like they only had one wire connector to assemble. Mine has 2 connectors. Is there a difference between AC and non-AC fan housings?

[cgsheen1]

Picture of yours please. There is a difference between the Factory A/C and Non-A/C models. But, it's not cables (well, I guess it IS cables... read on). The A/C models have vacuum bottles, vacuum solenoids, and vacuum actuators under the dash (a vacuum actuator on the right side of the blower housing for the mode door - where the non-A/C has one cable on the right side of the blower housing to operate the mode door.) I've not seen two cables on the right side of the blower housing - only one for the mode door and one to the left of the blower housing for the heater valve. (I have the '75 "museum 280Z" in the shop - it's non-factory A/C. I'll look at it's blower box.)

[Captain Obvious]

Assuming you're talking about electrical wiring connectors, I believe there is only one that goes to the blower box itself. There's a second one going to the blower motor, so if what you're looking at on ebay has the blower motor in place, there will be two connectors.

Not sure what year you're working on, but here's a pic from a 77 if that helps at all:

[Roblaw]

Yes, the extra wire connector goes to blower housing. Research tells me it is the heater resistor wire. My car came with AC (doesn't work) and the connector is longer and flatter, with 5 blades in it. The ones I see on Ebay are square with 4 blades. I assume they are from non-AC cars and maybe I have an extra blower speed. 

Anyway, it appears I can just put my resistor into the Ebay bought housing and be on my way. I will also have to transfer the vacuum pot for the fresh air door.

Anything I should know about the blower housings? I think they are the same with only add on accessories for AC.

[Captain Obvious]

There are more speeds for the A/C setup cars as opposed to the non-A/C. The A/C cars had four speeds and the non-A/C only had three. And yes, you can move the blower resistor over. They are interchangeable and mount the same in both housings.

The vacuum pot may be a little bit more complicated. I don't remember for sure, but I think there might be some welded or riveted bracketing difference between the A/C and non-A/C in that area. Might not be a simple bolt-up. Not insurmountable, but might not be that simple.

I've got some HVAC parts here that I have collected for various projects, and as is so common, I probably have more than I need. Haha! How much is the blower box on ebay you're looking at. I would have to look, but I might have one from an A/C car. PM me if that's of any interest.

[Roblaw]

There are 2 for $70 ea. shipped. Seems pretty reasonable. One with the motor but no vacuum pot, the other no motor but has vacuum pot. I'm leaning towards one with motor for redundancy reasons.

[Roblaw]

I accomplished some Z things today, thanks to Corona-quarantine. I finally have heated water going to my cabin. I tracked down the vacuum issue for the vacuum part of the water valve (AC car). Bad part is the water c*ck lever does not operate right (difficult to slide). So, I cannot control heat. I think it will either be full blast or not at all unless I fix water c*ck.

Captain O, I saw your write up about mounting one in the engine bay, and I may do something like that but I can't use the vacuum hose hole already in firewall. Plus the hose routing would be different unless I take the vacuum water valve out of the equation.

Anybody work with a generic water valve that was easy to install? I guess I'm gonna have to get it working correctly. I do have OCD tendencies.

Still waiting on my Ebay blower housing and switched gears a little, so recovered my seats. I had the passenger seat out anyway so I could get by body under the dash. Now all my fingers hurt. If you've ever done seat covers, you know what I mean.

 

[Captain Obvious]

Excellent. Sounds like great progress.

There was at least one person who mounted a new style water control valve in the interior compartment, but I don't remember who.

@grannyknot maybe? (This is apparently my go-to guess for someone if I can't remember who it was?     )

[grannyknot]

Page 8 about half way down,

 

Edited March 25, 2020 by grannyknot

[zKars]

Vintage Air makes a generic powered heater control valve.  It can be controlled by any rotary or linear potentiometer (0-10 kohm IRRC) you care to use. $90USD. 

50507-VUA - Servo Heater Valve Re-fit Kit with Control Knob and Pod

https://www.vintageair.com/instructions_pdf/50507-VUA.pdf

They also sell generic cable operated heater control valves.

Edited March 25, 2020 by zKars

[Captain Obvious]

4 hours ago, grannyknot said:

Page 8 about half way down,

Yup!! That's the one. Awesome! Thanks again for filling in the missing brain cells!

[Roblaw]

Got the water c*ck out. Not a horrible job and I have been dreading it and finding other things to do besides IT. Other than really stiff lever movement at 1st, it has really freed up and moves quite well now. Internally it looks really good. It hasn't moved in 20 years before I bought it. I think I'm gonna reinstall with new hoses and clamps. I already ascertained that the vacuum c*ck works when I restored vacuum to it.

Wish me luck.