914turboford

I put a 2000 Camaro LS1/4L60E into a 1989 Isuzu pickup. This is the pre S-10 truck, with more of it made by Isuzu than GM. The truck originally had a mechanical speedo. I found an Isuzu cluster with an electric speedo that fits in my dash, from a 1996 Rodeo. I have driven the truck but I can't get the speedo to work. I can't find a wiring diagram for the Rodeo cluster, but it has two wires that go to the speedo. I assume one is either 12V+ or ground and the other is a signal wire. I have read that the GM ECU speedo output from red pin 50 is a switched ground signal. Here is what I have tried so far:

1. 12V+ to the white isuzu speedo wire, black isuzu speedo wire to pin 50 on the LS1 ecu.

2. 12V+ to the black isuzu speedo wire, white isuzu speedo wire to pin 50 on the LS1 ecu.

3. Ground to the white isuzu speedo wire, black isuzu speedo wire to pin 50 on the LS1 ecu.

4. Ground to the black isuzu speedo wire, white isuzu speedo wire to pin 50 on the LS1 ecu.

The speedometer needle does not move under any of these conditions. Any ideas for what I should try next?

914turboford

There's nothing like having the wiring diagram. I was hooked up to the wrong wire in the cluster. I hooked the Camaro ECU's pin 50 to the correct Isuzu input to the speedometer (blue and black), put it in gear and the speedo works. It doesn't appear to be too far off from correct, but is probably reading a bit high.

stevieturbo

Unless you know the signal you're looking for...you're chasing your tail here.

A wiring diagram would help though.

Can you even find any details of what the Isuzu uses for a speed pickup on the vehicle ? Type of sensor ?

Honestbroker

I realize this is a little late, but I may be able to help you with some wiring diagrams.