1966 GMC 3/4 Ton Ignition question

[hammermouse]

I am working on a new to me project. I was able to locate a 1966 GMC 3/4 Ton 2WD that I am looking to rebuild/restore. Sorry for the long post....

When I received the truck, I had one key and one working lock (the door). The ignition lock was not in the switch and you used a key (or screwdriver) to turn the switch. I want to replace the switch/lock so that I have matching locks. No big deal I thought until the parts don't add up.

My ignition switch also looks like an aftermarket replacement (and appears to align with those used in a 74 Chevy). It is too small for the hole and doesn't use the original bezel. At first I purchased a new lock cylinder and bezel from LMC. When I went to use it I found that the bezel was too large (diameter) and the lock cylinder had different connect points into the switch. So I figured I'd replace the whole switch.

I purchased an AC Delco switch (D1437F) which is supposed to be correct (per AC Delco). It also aligns with what others point to at LMC truck, Bobs Chevy, and even OReilly's. When I go to replace it, I found that my ignition switch is a 4 wire and the replacement switch is 5 wire. When searching, I found several threads showing a 5 connector switch. OK, so I have both the original Service Manual and the original wire diagram book from GMC (found cheap on ebay and neither are reproductions). According to an original wiring diagram book the 1966 GMC I1500 only had 4 wires to it. The wiring diagram doesn't reference the dark green ground wire that I've seen mentioned on other threads and forums. I figured, no big deal...a ground is a ground and I can add it.

But then I go to put it in and the switch doesn't fit the hole. It's just a smidge too big. If I removed some of the flat spot (minimize it some) I believe it will fit. But...again....I realize that the new bezel is designed for the Chevy flat area around the hole and not my countersunk ignition switch hole. I also tried a BWD switch from OReilly that supposed to fit and it is almost identical to the ACDelco one I had (same crappy jam 'nut' and same diameter). The LMC ignition bezel DOES fit both the BWD and ACDelco switches, so they appear to be the right size...just not for my dash hole.

So my questions are:

- What switch do I use. Should I just adjust the hole and use the one that I have? Or is there a better one. (if this one, is there a better Jam Nut available as the one that comes with it is CRAP - thin stamped metal that you can rock back and forth over threads).

- Is there any way to obtain an original GMC 1966 bezel ring that fits the countersunk hole? It's definitely a factory dash with a factory hole.

- Did some factory glove boxes not have push button latches? Mine doesn't have one so I have to figure out how to modify it to add one or replace the door. The place for the striker is there, just missing the hardware.

New Switch:


Original Switch:


Diameter difference:


Dash with new bezel sitting in it:


Dash hole:




Thanks in advance for any help!!!!!!
Geoff

[hammermouse]

----Other Info----
As I am currently renting a house, I do not plan to do a full restoration at this time. I simply don't have the time/space to invest in it right now. Instead I want to rebuild/fix components to make the vehicle safe for small trips to local shows and excursions now while slowly building up piece parts for a general restoration to start next year in 2019 (hope to be in our own house by then). Right now that means fixing/replacing the brakes, brake lines, shocks, springs, suspension parts (ball joints, tie rods, etc), bench seat, steering wheel (cracked), ignition/locks, and cleaning the carb.

The truck sat for a few years before I got it. As a result, the carb is a bit gummed up. However.....it does run and I have driven it about 14 miles so far. I've got seafoam in the tank now to help the carb (part of why I drove it) and currently the truck idles and runs smoothly. No smoke, no knocks.

To stop the rust on key spots (hood, cab, grill) I used rust converter. It's simply to buy me some time to truly sand/fix the body. These parts were still good, the lower foot of the cab is a different story and I will need to weld in some panels and I'm looking at replacing the floor of the cab. That's why it looks like it has black eyes now.

Once I start full restoration, I am not planning to make it 100% authentic/original, but I do plan to take it close and make it nice and my own.

Here are pictures of the truck.













Aftermarket Air?:


When I first got it before driving it home and before I removed the home fabbed bull bar:

[Brentwe]

New myself, seems like a very knowledgeable and great group. Welcome from Canada.

[Captainfab]

Welcome to the forum

It has been my experience with the '64-'66 GMC's that they use the same dash switches as a '63 Chevy.

[Clyde65]

Welcome!

[DPowers]

Captainfab is correct I believe. Yours should look like this.

May try GMCPauls

60-66 Ignition Cylinder & Keys Each
133221 60-66 Ignition lock cylinder and 2 matching keys. $14.95

http://www.gmcpauls.com/60-66electricalswitches.htm

[hammermouse]

Thanks all.

That proves that it should be 4 wire, not 5. GMCPauls only has a Chevy one for sale (says it won't fit a GMC).
From researching Chevy switches, it 'appears' I need a GM 1116607, Delco D1432 switch (that's the old number and may just be a Chevy only one). I found several NOS of this part and they are in fact 4 wire, but the spade connections are turned different that DPowers picture (which leads me to believe that yes, it's a chevy specific part and won't fit GMC without modification). Not as much an issue since mine doesn't have the socket and I just need to add spade connections. But, I'll take a chance and give it a try.

For the bezel, I found a 61 chevy bezel that appears to be correct. So I'll take a chance there too.

Not very cut and dry for some pieces... O.o

[DPowers]

Let me know if you are still having problems. Probably have one in my stash someplace.

[hammermouse]

Thank you DPowers! The parts from ebay should be here in a few days. Shouldn't take too long to figure out if it will work. Only took 10 min with the last setvto figure out I was going down the wrong path...LOL

I took a look at your build page. Looks great!!!! I have to do a lot of body work before I will treat mine as a daily driver. But it'll get there.

[DPowers]

Thats what makes it fun.
Dont know if you do FB or not. We have a pretty decent TN FB page.

[hammermouse]

I'm on FB. Sometimes it's the only way I hear from family or old friends sometimes. What's the group/page name?

[hammermouse]

Well, I received my parts today. The bezel is correct for what I need. I'm questioning the switch. Part is a Delco Remy 1116607 as advertised but connections are:

- SOL
- BAT
- IGN1
- GRD

ACC is empty.... Confirm that with a key, it only has off-on-start. No ACC position.

Is this correct for my GMC? It does fit the hole... When I compare it to the picture DPowers posted, mine has a lead (GRD) where there is a hole on DPowers switch... And DPowers switch has a lead where mine is stamped ACC (but nothing is there). So I'm assuming it's wrong and may 'work' but not correctly...

[hammermouse]

I decided to try again. Found a NOS Delco 1116639 / D1442 switch. It has :

- BAT
- IGN1
- SOL
- ACC

No ground which matched the old aftermarket switch and the wiring diagram. Only negative... Since it was truly an old style switch, there isn't an ACC position.

Redid the wire connectors to spade and mounted it up. Little starter fluid and the engine fired up and turns off as expected. Yay me.

[DPowers]

Good deal