91 K5 spedo does not work

[84CUCV]

No idea what is going on with this. When i am doing about 60mph the engine light comes on, then goes out. After that the spedo needle jumps up and down and the e break light stayes on. So what is up with my truck? Could it be a bad cable on the spedo? thx for the help

 

[scooter122983]

In 91 there is no speedo cable it is a vss located on the tailshaft housing. You also have a rear wheel anti-lock brake module next to the brake master cylinder. The vss sends the signal to the module and after the module it goes to the computer, after the computer it then finally goes to the gauge. Check the brake module connections since the e-brake light in this model is also the RWAL brake light. And if the brake module is shot the speedo will not register correctly if at all.

 

[84CUCV]

What do you mean by RWAL?

 

[obijuan]

rear wheel anti-lock

 

[84CUCV]

OK thx

 

[84CUCV]

Where can i get a scaner so i can go see what codes i have? I would think they are all just about the same. right??

thx mike

 

[southernspeed]

Just put a jumper wire or paper clip between a and b on the aldl and the SES light will flash codes starting with the code 12 handshake 3 times and then any stored fault codes.

 

[randy88k5]

FWIW, my check engine light came on in my 88 when I broke the speedo cable. It was the computer bitching at me because it couldnt lock the torque converter.

 

[84CUCV]

OK thx guys