89 K5 (technically v10). Vehicle speed sensor issue. Help?

[buckallred]

700r4 & NP241 transfer case.

I replaced the OEM dash with the DIY4X competition dash. In doing so, I replaced the OEM gauge cluster with autometer gauges.

It turned out great. One problem. In 1989, the vehicle speed sensor is a 1 in x 1 inch light green square doodad attached to the OEM speedometer. I basically tossed it or otherwise lost it.

Now, the vehicle runs just fine, but the check engine light pops on intermittently because the Engine Control Module (ECM) is not getting a signal from the vehicle speed sensor ... because there is no vehicle speed sensor.

I'm in California and this would cause me to fail smog. Thus far I've gotten lucky (the light hasn't popped on during the smog test).

The fix is to get an aftermarket vehicle speed sensor and plug it in on the side of the transmission / transfer case, then plug the speedometer cable into it and wire the aftermarket speed sensor to the ECM.

1) Aftermarket vehicle speed sensor: I understand this needs to be a "2K pulse" speed sensor. I believe this one is the correct one: https://tpiparts.net/inc/sdetail/11046/7586

Can anyone confirm that that is correct?

2) I'm going to have to get the ECM out and figure out where to plug in the wire from the vehicle speed sensor. This may seem obvious to some or all of you, but I have no clue. I have a Hayes manual and a Chilton manual, and they seem to be of no help.

Can anyone help me or point me to a source of information for figuring out where to connect the wire from the aftermarket speed sensor to the ECM?

Yes, this was a stupid thing to do and I wish I had never fiddled around with it in the first place. Thanks for any and all help!

 

[dyeager535]

Depending on cost and complexity, you could convert the 241 over to the 90-91 VSS setup too, but I assume that would be more work. Not sure what the cost vs. benefit is on that one.

IIRC A10 is the pin you want, but verify. The service manuals available here should be of help to you: http://67-72chevytrucks.com/vboard/showpost.php?p=5621043&postcount=1

FWIW, not a big fan of cutting stuff, if you didn't remove the actual harness for the VSS, the wire you need should be right behind the cluster anyway.

 

[buckallred]

This helps, thanks very much. I didn't cut wires, so will get in the dash and should be able to find which wire I need to connect to the aftermarket vehicle speed sensor. Appreciate the help!

Depending on cost and complexity, you could convert the 241 over to the 90-91 VSS setup too, but I assume that would be more work. Not sure what the cost vs. benefit is on that one.

IIRC A10 is the pin you want, but verify. The service manuals available here should be of help to you: http://67-72chevytrucks.com/vboard/showpost.php?p=5621043&postcount=1

FWIW, not a big fan of cutting stuff, if you didn't remove the actual harness for the VSS, the wire you need should be right behind the cluster anyway.

 

[Wiregeek]

I gotta ask, whaddya mean 'technically V10'. You put two extra cylinders in there?

 

[buckallred]

I gotta ask, whaddya mean 'technically V10'. You put two extra cylinders in there?

heh, no. The 1989 K5s were called "v10," not K5. Sometimes people like to argue about this (I am not one of them). Some other people like to correct others who call 1989s "K5s." It doesn't matter to me, but the correct term for a 1989 Blazer is a "V10." It has the usual smallblock 350 engine. . .

 

[Wiregeek]

Oh, cool. Understood about not liking to argue about it (though I can be the kinda guy that does like that argument).

I think a v10 blazer would be.. interesting. I spent some time in a v10 dodge pickup, it was surprisingly good when it worked.

 

[dyeager535]

heh, no. The 1989 K5s were called "v10," not K5. Sometimes people like to argue about this (I am not one of them). Some other people like to correct others who call 1989s "K5s." It doesn't matter to me, but the correct term for a 1989 Blazer is a "V10." It has the usual smallblock 350 engine. . .

I think GM did this just to give us something to talk about years later. GM changed the truck bodyline designation from C/K to R/V in 1987, in preparation for the 1988 IFS trucks. Of course, keeping the old and new body styles running concurrently made a mess of buying parts for decades lol. Luckily nowadays they seem to have most of that sorted out.

Interestingly (to me), in 1982, GM changed the designation of the A-bodies (Cutlass, Regal, Monte Carlo, etc) to G-body, even though the actual body change occurred in 1981.

Obviously the body designations changed as new body styles came on the scene, but still, would have been nice if GM had kept those designation changes to the year the body styles changed significantly.