hey guys. i recenlyt took my computer controlled carbed 305 and replaced it with a carbed 350. So seeign as i didnt need the computer anymore i removed it. Now did i need the computer for my speedo to work? or should it work with just the buffer.

 

I am no authority on the subject but I think you needed the computer to convert the signal. I swapped in an electronic speedo into my car and from my research in order to get it to work right I needed to get a unit from Dakota Digital that would let me convert the signal so the speedo would read correctly. It works well but be prepared for an $80 Visa bill. If you haven't yet, do a search and look around. You will probably find a definitive answer that way.

HTH

 

It will work with just the buffer - that's how mine is.
You should trace the yellow and purple wires going to the sending unit on the trans to make sure they are not cut anywhere. They go out to the engine compartment in the same bulkhead connector as the rest of the wiring from the ECM, the one just in front of the passenger doorjamb.

Pete

 

well this could be a problem then. I removed the entire engine harness because i didnt need it. Now i found a small connector on it with the yellow and purple wires but i cant see a connector anywhere else where it would connect. now there is another connector hanging under the dash where im guessing it used to plug into the computer. but there was no other connectors in the harness when i pulled it out. I'm Lost.

 

Here's the piece you need...
<img src="http://www.hioutput.com/tech/buffer.gif">

Wires, from the top, are:
Purple
Yellow
Pink with black stripe
Brown (2)
Green with black stripe
Black with white stripe

 

so thats what the buffer looks like huh? ok well i see that purple and yellow wire with the connector and that is exactly what is hangining down under my dash. But i never removed the buffer box. i only removed the ECM. thsi is gettin stranger and stranger by the minute.

 

Time to do a couple of quick checks.
On the lower connector, check for 12V in the pink wire when the ignition is 'on', and check for ground in the black wire. The green wire sends the signal to the speedo head.
If you have 12V and ground, then either the buffer box is bad, or it isn't getting any signal.

 

well i would do that but i just went under my dash and there is nothing like that under there. Now heres my next question, is the buffer attached to the ECM? like with a metal clamp or somethin. cause there is nothing under my dash that looks even remotely like that. i even pulled off the middle part where the performance suspension badge is and there is nothin like that under there either. so either i pulled it out with the ECM as one piece or it was removed by the previous owner, but the speedo worked when we drove the car home before i swapped the motor.

 

It's attached to a plastic bracket which is bolted to the ECM case.

 

yep i pulled that along with the computer . ok now i gotta find the computer. Thanx pete you rock dude.