Which Lower Column Ignition Switch Do You Need (not the key switch)

I alluded to this in another thread, that basically ALL 78-88 G-bodies used one of two lower column ignition switches depending on the column used, whether tilt (RPO N33), or non-tilt (standard column).

Unfortunately, all the column ignition switches are discontinued from GM, but you can still find them new on the secondary market, like ebay and facebook, swap meets, etc. And again, unfortunately, unless you fall into it, they're not getting any cheaper when you do find NOS GM ones. I've seen them from 30-50 bucks on norm now. They used to be a $10-12 part.

The STANDARD NON-TILT ignition switch is GM p/n 1990115, ACDelco p/n D1404B. It will NOT interchange with a tilt switch. Don't even try.


The TILT wheel column uses switch GM p/n 1990116. The only real difference is the the direction the ignition switch moves. It's either pushed or pulled depending on which column you have. Tilt pulls, standard pushes, IIRC.


But there's two others I've found that MIGHT work with a little massage. They used them on A and X-bodies of the 80s (FWD) and F-bodies mainly, with console (RPO D55) and automatic transmission. They have a cable lock on them to prevent the switch from activating if it's in anything but Park or Neutral.

The potentially alternate GM p/n's are:
1990114 (superseded by 7843451), and 26036235. The first number apparently fits 3rd gens, and the second number fits the last couple year 3rd gens and 4th gen F-bodies. I can't get good clarification on that. There's something a little different with them between the two, but I can't find what that exactly is. They're basically setup like a tilt wheel G-body (116 part) switch but . The automatics with floor shift use these numbers, but the manual trans uses the 115 and 116 switches. The automatics with floor shift uses the strange numbers. An interesting thing is, the switch I ordered is stamped 114, meaning 1990114. So is the switch the same? Or not? I've got a sneaky suspicion that the guide is different on the newer version vs. the older version guide. Meaning that's why the p/n aren't supersession numbers, they're two stand-alone numbers because of something being different between them.

As mentioned, there's an immediate difference about them and it's rather apparent. On the base of the switch, there's a huge plastic "guide" for a cable pull insert from the transmission gear shift on the floor. There's a pin that the cable insert blocks if the switch is not in Park or Neutral. Exactly how it works, I don't know. But it's a mechanical stop. Keeps you from starting the car unless in Park or Neutral.

Thing is, there's two little philips screws holding this piece on. Plus a little clip on the base. Everything I've researched so far says you can just undo the two screws and pull off the cable guide, and you should be in business with a 116 switch. Or, technically you don't do squat, let the guide just sit there as it is kinda out of the way, and if it doesn't hit anything underneath, just use it as is. I'm going to find out.

I was able to scare up a GM switch p/n 26036235 for cheap so I can try this experiment. If it works, great. If not, I'll put the guide back on and sell it to a 4th gen F-body guy. Or steal parts out of it and refurb an original used Delco switch.

SMP299, the 26036235 equivalent:



Not sure when they started using this, but if you notice some of the newer switches, GM or aftermarket, they have the two blank tabs on the back side of the switch base so if they used the guide they'd punch the screw holes. The original production units did not have these tabs.

Newer version with tabs


An older original. Look ma! No tabs!


What's kind of silly is that I used to have a 26036235 in a baggie for the wife's '02 Z28 as it had an automatic. But I sold it when I dumped a majority of my 4th gen stuff after selling the cars. Should have took it out of the baggie.

I got an idea what's inside these ignition switches, as I busted one in the junkyard trying to get a column away from a smashed dashboard (crashed car) many many moons ago. I KNOW they can come apart, so when I get around to it, I'll take a GM one apart and clean it up and possibly "restore" it. Just because. When I do, I'll post up here how its done. Unless they get burnt up and melted/cracked, I'm betting a worn switch can be refurbished. These switches are robust and can handle a lot of abuse. To a point.

When it comes to aftermarkets, I'm betting most will work, but I cannot vouch for those as I haven't really researched them diligently.

Ok, my new 26036235 (ACDelco # 1473C) igntion switch for fitting a 4th gen automatic arrived today.

Just as I suspected, the last three of the part number (114) was ink stamped on the part.

This means it started out life as a 1990114 (ACDelco # D1405B ), superseded to a 7843451(ACDelco # D1408B), then changed p/n's again to 26036235. They won't tell you that in the parts information. They act like it's a new part. Standard Motor parts lists the third gen F-body part as US-131, and the 4th gen F-body part as US-299. Now, as the SWITCH is the exact same, my money is on that little cable thingie that screws onto the switch. There may be differences in how that part is configured or shaped. That may be the issue of why it's not a straight up supersession. I don't know, as I don't have an older one to compare.

Check it: Here's a 7843451. Note it has the last 3 numbers of the part number (114) on it.


MY Switch:



Imagine that, there's that pesky 114 again.


The pins are set up EXACTLY like the 1990116 (D1405B), which would be the "correct" part number for the G-body tilt.




Let's see if we can turn this into a 1990116, something that we can actually use.
First, let's remove those two pesky screws holding that Park/Neutral shifter lock cable thingie.


That was easy. Again, as suspected, the cable lock thingie comes off, and you're done. That round thing on the attachment is a spring loaded pin that I'm supposing a wedge piece slide dealio on the cable from the shifter pushed up on when not in park or neutral.


Note the bottom of a later model 116 switch. Look at that. Exactly the same base.


Interesting that I can't seem to find the ACDelco # for the 1990114, but it does exist as stamped on this D1408B....



That's it. I guess you could even use it without taking off anything, because the spring loaded pin in the plastic piece stays out of the way without anything hooked up to it. But it may get in the way of other wiring, but that'd be up to you.

So theoretically, there's several part numbers that can be used for a G-body tilt steering column substitute for the 1990116. Just remove the plastic piece from the bottom (or side, once mounted) plate and roll with it.

1990116 (ACDelco # D1406B)
*7843451(ACDelco # D1408B)
*1990114
*26036235 (ACDelco # D1473B)

* = remove two screws and cable guide from baseplate

Thing is, I provide the part numbers to help you in your search, but keep in mind, GM does not stock these switches any longer. So it's going to be tougher and tougher to find them. But the more fish in the pond, the better chance you can score what you need for as cheap as possible. Good luck.

Aaand, as an added bonus to this thread, maybe this will give you an idea of what the cable end looks like on a Firebird, Camaro, X-body, FWD A-body, etc., that uses this lock part...

Keep in mind that this switch is made certain mid to late 80s -2002 model F and X cars with the auto on the floor AND Tilt wheel. Earlier F-bodies I know used the same 115 (standard column) or 116 (tilt) switches, depending on column used. I did find out more about that cable lock. It's purpose is to act like the backdrive linkage to the ignition switch on a G-body. It appears it keeps you from taking the shift lever out of park with the key out and ignition is in lock, and keeps you from turning the key back to lock once you have it in run if you're out of park. F-body autos had a separate park/neutral start switch in the console area to keep the car from starting if not in park or neutral. Likely others that used this switch did too.


Cable is #5, the park/neutral safety switch is #16.




But if you're in a junkyard, keep in mind these cars are another source for an ignition switch if you absolutely need one for a tilt wheel G-body. You can snag it and just remove the little philips head screws and take the switch with you.

In my head, I couldn't figure out how this think worked or why it was really needed. Now I have a better idea. Here's the adjustment procedure for the automatic floor shift cars with the lock cable. I'd rather have my G-body backdrive linkage junk.


If you have to remove the switch from that cable, press down on the clip designated by the yellow arrow.


and here's what you get. It's a little wedge slide that presses on the spring loaded pin to do its job. Again, see yellow arrow.