[rls196906]

I was wrong and stand corrected. 94 uses a VSS in the trans. If your 700r4 is older it might have a cable setup. Jags That Run (JTR) has VSS's that will connect to them. You may still need to correct the gears to get an accurate speedo. Or you might be able to get a adjustable DRAC. It's between the VSS and the speedo.
Look on the side of the trans case on the passengers side oilpan rail there is a number stamped into the case giving the year of the trans. While you are down there see if it has a threaded fitting for a cable or a VSS to connect 2 wires to. On the drivers side tailhousing.

Thanks now I know where to start.....once I see what I have I'll report back. All this help is awesome. Thanks to all.

 

[Brawndo]

@oldeerslayer no worries as i am getting well into my gray haired years. @rls196906 do you still have the stock computer in you blazer? Reason i am asking is for speedo function. Trying to figure out if the speedo can be made a stand alone function without the computer. Wonder if anyone has a wiring diagram that would detail it?

 

[oldeerslayer]

Yes. in 94 the speedo doesn't go thru the computer. That started in 96. Above the ECM behind the glove box is the DRAC. The VSS goes directly to that module and it sorts the signal out for different outputs for the speedo, cruise, ABS, etc.
That much I do remember after being woke up.
Here's what a 94-95 VSSB DRAC module looks like.

 

[rls196906]

Hey there youngster.....I love posts with pics. You're the CATS PAJAMAS and we know only the two of us knows what that means.

Is there a way to test that VSSB DRAC module???????

I see you want me to get under the dash on the passenger side as well. Seems I better get that milk crate and wide board soon. As they say in our circles, Youth is wasted on the young. Thanks for the post partner.

 

[rls196906]

If it makes a difference, my Blazer no longer has cruise as when it became carbed, all that stuff went away. I'm trying to see what all that 94-95 VSSB DRAC module controls and senses. If this posts means nothing, let's pretend I didn't post it, and you didn't read it.

 

[rls196906]

Thanks now I know where to start.....once I see what I have I'll report back. All this help is awesome. Thanks to all.

I did get the Blazer jacked up on the passenger side but I didn't have the GUMPF to crawl under and get the trans number and see what's up. Everywhere I looked I found wet spots on my concrete floor, and then realized I didn't have an accident, but rather it was 95 degrees in my garage and like Frosty the Snowman, I was melting away. Tomorrow's another day. Wish I could get the wife to slide under there for me. She fell for that trick once. Like when I proposed to her.

 

[rls196906]

And today's lucky number on the tailshaft is:

 

[rls196906]

And we also have these photos from the driver's side tailshaft and showing 2 electrical connections.

 

[Brawndo]

Appears to be a 700r4 Perhaps we can get @Tranzman to weigh in to give a definitive answer.

 

[rls196906]

Appears to be a 700r4 Perhaps we can get @Tranzman to weigh in to give a definitive answer.

I like the way you think Brawndo...........

 

[rls196906]

I need some sound advice on where to start to analyze (why is the word ANAL in analyze?) where the problem may be. I am guilty of throwing good money at something and end up with it being a simple less expensive repair. In my old age, I need to watch my money closer now since I retired and can't give myself a pay raise. Let's see where this leads.....

 

[Tranzman]

And we also have these photos from the driver's side tailshaft and showing 2 electrical connections. View attachment 365402 View attachment 365403

First veiw is the VSS sensor & the last photo proves you have a 700R4 Transmission. it is the 3 wire TCC connector. This has nothing to do with speedometer function. it does however need a VSS signal to work properly.

 

[PeteD]

Thanks for the tech info. I wasn't sure where to start. I need to get an assembly manual one of these days.
I'm 71 years young so my ability to work under the dash and other tight places is somewhat limited. But, I always
try to fix something myself, because you will always gain knowledge.....sometimes good.....sometimes NOT SO GOOD.

Always advisable to have vehicle shop books. Great way to find diagnostic tips (like grounding oil sender wire) as a gage ck. And other neat stuff to avoid chasing ones own tale before possibly needless disassemble.

 

[oldeerslayer]

Appears you have an 89 or newer 700R4 with a VSS. Good news. Now see if you have the VSSB/DRAC. You should be able to see it by pulling the glove box out. The little white box I showed you a couple days ago. If it's there check that you have continuity with an ohm meter from the wires at the trans (VSS) and at the DRAC.
Then check you have continuity on the lt/blu/blk wire from pin 15 of the DRAC to the instrument cluster pin 14.

Gotta watch out for that Tranzman guy. He's nearly as old as us and knows more about transmissions that we'll ever be able to learn.

 

[rls196906]

Appears you have an 89 or newer 700R4 with a VSS. Good news. Now see if you have the VSSB/DRAC. You should be able to see it by pulling the glove box out. The little white box I showed you a couple days ago. If it's there check that you have continuity with an ohm meter from the wires at the trans (VSS) and at the DRAC.
Then check you have continuity on the lt/blu/blk wire from pin 15 of the DRAC to the instrument cluster pin 14.
View attachment 365425

Gotta watch out for that Tranzman guy. He's nearly as old as us and knows more about transmissions that we'll ever be able to learn.

I heard rumors of that Tranzman guy, but even though they were good rumors, that didn't stop me from taking his advice.

Thank you for posting the circuit diagram and the much needed instructions to test. I may not get to it today, but as soon as I can. I think I'll cut a hole in the firewall instead of taking the glove box out. That's what they call "thinking outside the box isn't it"?????????????????? JUST KIDDING. Have a blessed day all. 😇

 

[Tranzman]

Appears you have an 89 or newer 700R4 with a VSS. Good news. Now see if you have the VSSB/DRAC. You should be able to see it by pulling the glove box out. The little white box I showed you a couple days ago. If it's there check that you have continuity with an ohm meter from the wires at the trans (VSS) and at the DRAC.
Then check you have continuity on the lt/blu/blk wire from pin 15 of the DRAC to the instrument cluster pin 14.
View attachment 365425

Gotta watch out for that Tranzman guy. He's nearly as old as us and knows more about transmissions that we'll ever be able to learn.

I may know about the inside of the transmission, but I fall short in the wiring department. Seem's like oldeerslayer has all that covered for us!!! I turn 66 this January and some day's I feel 80 plus. I could do more if my knee's allowed it!

 

[Rhotpursuit]

I may know about the inside of the transmission, but I fall short in the wiring department. Seem's like oldeerslayer has all that covered for us!!! I turn 66 this January and some day's I feel 80 plus. I could do more if my knee's allowed it!

 

[rls196906]

I may know about the inside of the transmission, but I fall short in the wiring department. Seem's like oldeerslayer has all that covered for us!!! I turn 66 this January and some day's I feel 80 plus. I could do more if my knee's allowed it!

It's okay Tranzman, I have bad KNEES too. I have bad kidKNEES, and some days it my hyKNEE that has pain in it.
You can practically smell the BenGay permeating from the screen as you read these aches and pains can't you???

I know it's my attempt trying to keep some assemblance of my youth thinking I can still do the things I used to. But thanks to Amazon, if a tool falls on the floor, and rolls under the car, I quickly see what the price of a new one is, and decide then and there, is it worth crawling on the hard concrete floor to try to reach that tool lying smack dabb in the middle, or do I just click "ORDER NOW" and a new tool will arrive in a few days. ???

I believe I have nearly a whole toolbox of tools under my car. But any reason to buy a new tool is a GOOD REASON!!

Please don't judge me......because deep down inside, you know you do the same thing. Time to order a new socket!!

 

[Tranzman]

It's okay Tranzman, I have bad KNEES too. I have bad kidKNEES, and some days it my hyKNEE that has pain in it.
You can practically smell the BenGay permeating from the screen as you read these aches and pains can't you???

I know it's my attempt trying to keep some assemblance of my youth thinking I can still do the things I used to. But thanks to Amazon, if a tool falls on the floor, and rolls under the car, I quickly see what the price of a new one is, and decide then and there, is it worth crawling on the hard concrete floor to try to reach that tool lying smack dabb in the middle, or do I just click "ORDER NOW" and a new tool will arrive in a few days. ???

I believe I have nearly a whole toolbox of tools under my car. But any reason to buy a new tool is a GOOD REASON!!

Please don't judge me......because deep down inside, you know you do the same thing. Time to order a new socket!!

ROFLMAOX2
First I grab a magnet, cause most of my tools are Snap-On or Matco (depending on which box it came from). A 10mm short 1/4" drive is $22. I'm so anal about my sets that I won't put a cheapie tool in it's place...
Your right though any reason is a good reason to but a new tool!!!

 

[rls196906]

I stopped removing screws trying to remove the glovebox. WHY?? After a good 10-12 screws, which I thought is excessive to just pull a glovebox, I didn't feel like pressing my luck. I removed some small access panel at the back of the glovebox hoping the VSS was there, but no such luck. Just a hose.

I'll need to get a manual and get instructions on what and how to remove the glove box.

I was never a good swimmer. I learned to wade in the water, not just jump head first seeing fins in the water.

I laughed and thought, after all the screws and the glovebox still wasn't coming out, GM spent a lot of effort, and money securing this to the car. They could probably use that focus on some other parts.

Until later...........project on hold.