Speedo quit working.

[Vbb199]

OK, so I'm not trying to be a selfish ***** and flood GMSB with stuff about my truck, but I have a quick question, because I just wanna know how it works.
Truck is a 89 burb, tbi 350, 700r4.


My 89 no longer has a working speedo as of today, and 4th gear also does no lock up anymore.


I'm gonna take a guess to say the two are related?
I have spare speedo cables, so its not an issue to replace, and magically 4th gear is also acting up at the same time as well as the engine light is now on.
Truck seems to shift totally different now.

So I'm sure more than likely, since the ECM isn't getting readings anymore, it's probably safe to assume the ECM has went into some default transmission setting??

As I said, I'm not asking how to replace the cable, or "whys my speedo not working"

I'm more so interested to know if it's all tied together, just wanting to learn.

Thanks guys as always! !!

 

[Goldie Driver]

Not real familiar with the later ones - I will guess and say VSS not working.

Does yours have one ? Well, not sure.

Selfish ***** ...

J/K !!

Free bump.

 

[Big Chip]

You must be registered for see images attach

 

[Vbb199]

Not real familiar with the later ones - I will guess and say VSS not working.

Does yours have one ? Well, not sure.

Selfish ***** ...

J/K !!

Free bump.

Still uses a cable. Its cable driven!!!!!

90 and 91 uses VSS

 

[Vbb199]

You must be registered for see images attach

Damn. Lmao

Why? That's all I gotta ask. Lol

 

[Goldie Driver]

Still uses a cable. Its cable driven!!!!!

Well, hell. Some of those later ones had some weird deal - DRACS ? - but I am just not familiar with them. Weird that a cable driven one would quit working at the same time the tranny starting acting up, so I follow your logic there, right or wrong.

NVM me - just here for the ride.

 

[Big Chip]

Damn. Lmao

Why? That's all I gotta ask. Lol

Because I don’t have an answer for you.

 

[Vbb199]

Well, hell. Some of those later ones had some weird deal - DRACS ? - but I am just not familiar with them. Weird that a cable driven one would quit working at the same time the tranny starting acting up, so I follow your logic there, right or wrong.

NVM me - just here for the ride.

90 and 91 both have a DRAC (for tire size and gear ratio programming), and a VSS.

This is just a cable, drive and driven gears in the tranny

 

[Vbb199]

Because I don’t have an answer for you.

Well that ***** retarded.

But I laughed.

 

[Goldie Driver]

90 and 91 both have a DRAC (for tire size and gear ratio programming), and a VSS.

This is just a cable, drive and driven gears in the tranny

Gotcha.

Stupid questions - have you already pulled the upper & lower cables off the cruise module ( if there) and check if they turn by hand ? Focusing on the speedo issue.

 

[Blue Ox]

When I read the thread title my first thought was that it was about a wardrobe malfunction and all I could think was, please dear God, no pictures this time!

 

[Matt69olds]

Without a speed signal, the converter won’t lock, and the cruise won’t work, etc.

If the speedo is cable driven, make sure the cable turns with the driveshaft spinning. If it’s an electric speedo, check the wiring, the connectors, look for corrosion or broken wires.

 

[Vbb199]

When I read the thread title my first thought was that it was about a wardrobe malfunction and all I could think was, please dear God, no pictures this time!

"this time"

What's that mean? Lmao

I'll have you know, I wear boxers

 

[Vbb199]

Gotcha.

Stupid questions - have you already pulled the upper & lower cables off the cruise module ( if there) and check if they turn by hand ? Focusing on the speedo issue.

No sir, I haven't done anything yet, and it's raining here!

 

[Bextreme04]

Doesn't the 89 have a cable driven speedo cable that drives that weird light sensor dealio? Its the sensor that feeds the pulse signal to the ECM, right?