How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Chevy expert Your Own Question
Chevy expert
Chevy expert, ASE Certified Technician
Category: Chevy
Satisfied Customers: 10370
Experience:  30 yrs experience ase cetified tech shop owner
Type Your Chevy Question Here...
Chevy expert is online now
A new question is answered every 9 seconds

1993 chevy: speedometer quit working..shifting..buffer connector

Resolved Question:

1993 chevy k1500 that the speedometer quit working and the transmission quit shifting at the same time. this truck has the speed buffer/convertor. I have a good vss signal at the buffer connector with it unplugged but as soon as the buffer is plugged in the vss signal drops to 0. I substituted a new vss sensor and ran temporary wires directly to buffer with no change. I tried a used buffer with no change and i cut the output wires for the buffer to see if they were pulling the voltage down with no change. I also loaded the powers and grounds for the buffer with a headlamp and both are good. It seems like buffer is bad but having a hard time believing that two of them would do the same thing? Ideas?
Submitted: 5 years ago.
Category: Chevy
Expert:  Chevy expert replied 5 years ago.
Welcome to just I'm here to help you and your 100% satisfaction is my goal. Have you tried replacing the buffer itself?At the buffer, verify the Pink/Black wire is 12 volts key on and the Black wire
is chassis ground. If OK, then with the buffer plugged in, backprobe
a voltmeter one lead to the Purple/White wire and the other lead to the Light
Green/Black wire with it set to AC volts. With the wheels spinning,
verify it generates over 1 volts AC. If it does not, then check the wires back
to the output speed sensor for problems.
Customer: replied 5 years ago.
Did you read my post? All of your questions/comments are there
Expert:  Chevy expert replied 5 years ago.
Yes from your description I would say you have a defective buffer replace it because it is dragging the V SS signal to down to zero
Chevy expert and 2 other Chevy Specialists are ready to help you