A few random questions (that I didn't find answer to in the FAQs)

[Jimal]

1. I'm replacing the Thrift Air control cable/fan motor switch in my truck. The switch I ordered from LMC has more terminals than the original, and the connector is different. The three wires that go to the resister are self explanatory, but the supplemental shop manual I recently purchased doesn't include this circuit in the wiring diagrams.



Which of the two pictured terminals takes power, and what does the other one do?

1a. Where does the Thrift Air circuit get its power?

2. How screwed up are the ends of my frame?





3. Does anyone have pictures of how the rear bumper bolts up? I have a freshly powdercoated bumper and a bunch of brackets that I don't know what to do with.

Thanks,
Jim

[Mathew21]

I asked the same question about the rear bumper. Here's my thread. Scroll down to the bottom. The photo's really helped me.
http://67-72chevytrucks.com/vboard/s...d.php?t=632243

[Jimal]

Originally Posted by Mathew21

I asked the same question about the rear bumper. Here's my thread. Scroll down to the bottom. The photo's really helped me.
http://67-72chevytrucks.com/vboard/s...d.php?t=632243

Thanks. Now I just need to see if my stack o' brackets contains brackets that look like those.

[cortcomp]

The stepside and fleetside brackets look close but the stepside brackets (outers) won't reach the bumper on a fleetside. I learned that the hard way when someone gave me some brackets. Had classic next day me some brackets, to the hotel at a car show, and installed them in the parking lot. Once you see how they go, not that bad.

Can't help you with the thrift air, because i'm balling big with the deluxe heater ;-)

There are wiring diagrams online on this site and all over, just keep looking. Google image search is amazing, hope this helps.

[pimpston65]

looks like someone cut too much off the rear frame for some reason cuz those holes left dont look right and its way too close the the left springs

[LostMy65]

I've been digging through the forums to try and find an answer to your switch question.
I did find this cool thread;
http://67-72chevytrucks.com/vboard/s...=heater+switch

[bhc41051]

Hey Jimal, I think you're missing your mounts for the rear sill. I'm 99.9 percent certain that Chevy/GMC never offered the rear "sport" bumper on the short bed K model pickups. The 4x4 Suburbans had a frame extension. The two wheel drive brackets won't fit. You'll have to fab some brackets if you want the "sport" bumper. You'll also need to fab some brackets to mount the rear sill of your bed.

[argonaut]

Wow, I have never seen rear sill tabs on the frame like that before. Is your truck a 60-62 by chance? The older 2wd frames were wider and thus so were the mounting positions on the bed rails. But maybe all the 4wd frames were narrower like the later model 2wd frames.

When I put a 62 bed onto my 66 k10 instead of replacing the rear sill I just drilled out the spot welds on sill mounts and tack welded them into the narrower position to sit directly on the frame rail, like thr 63-66 pickups.

[Jimal]

Originally Posted by cortcomp

The stepside and fleetside brackets look close but the stepside brackets (outers) won't reach the bumper on a fleetside. I learned that the hard way when someone gave me some brackets. Had classic next day me some brackets, to the hotel at a car show, and installed them in the parking lot. Once you see how they go, not that bad.

Can't help you with the thrift air, because i'm balling big with the deluxe heater ;-)

There are wiring diagrams online on this site and all over, just keep looking. Google image search is amazing, hope this helps.

Those are the diagrams from the shop manual. What is missing is the wire color. I have a couple random wires hanging under my dash that I'm trying to find a use for.

Originally Posted by LostMy65

I've been digging through the forums to try and find an answer to your switch question.
I did find this cool thread;
http://67-72chevytrucks.com/vboard/s...=heater+switch

Thanks. I searched "thrift air" and didn't find this thread for some reason.

[Jimal]

Originally Posted by bhc41051

Hey Jimal, I think you're missing your mounts for the rear sill. I'm 99.9 percent certain that Chevy/GMC never offered the rear "sport" bumper on the short bed K model pickups. The 4x4 Suburbans had a frame extension. The two wheel drive brackets won't fit. You'll have to fab some brackets if you want the "sport" bumper. You'll also need to fab some brackets to mount the rear sill of your bed.

I have a new, in the box sill from Mar-K. I'll have to see how it sits on there. There are a bunch of little metal plates poorly welded onto the frame that I'm going to remove as well.

[Jimal]

Originally Posted by LostMy65

I've been digging through the forums to try and find an answer to your switch question.
I did find this cool thread;
http://67-72chevytrucks.com/vboard/s...=heater+switch

That thread has a lot of interesting ID and parts interchange info, but nothing on this switch. So I did what I should have done to begin with and broke out my Fluke. What I found is that both B and C terminals close the circuit with the L, M and H terminals. What I'll do is power B and cap C somehow.

[Jimal]

Originally Posted by bhc41051

Hey Jimal, I think you're missing your mounts for the rear sill. I'm 99.9 percent certain that Chevy/GMC never offered the rear "sport" bumper on the short bed K model pickups. The 4x4 Suburbans had a frame extension. The two wheel drive brackets won't fit. You'll have to fab some brackets if you want the "sport" bumper. You'll also need to fab some brackets to mount the rear sill of your bed.

This must be a thing with the earlier trucks, because my rear sill lines up just fine.

[61K10]

my 61 has the tab's for the rear sill. the early trucks used the 2wd sill from the x frame thus the brackets.

[Dhaak64]

Originally Posted by Jimal

1. I'm replacing the Thrift Air control cable/fan motor switch in my truck. The switch I ordered from LMC has more terminals than the original, and the connector is different. The three wires that go to the resister are self explanatory, but the supplemental shop manual I recently purchased doesn't include this circuit in the wiring diagrams.



Which of the two pictured terminals takes power, and what does the other one do?

1a. Where does the Thrift Air circuit get its power?

Did you ever figure out the LMC thrift air heater switch? I just got one and I'm in the same dilemma.