V6 to V8 swap gauge problems

[88 Z28 Guy]

Just got finished doing V6 to V8 swap and now my gauges are acting funny. Tach and speedo are way high. Also my fuel gauge is pegged straight to the right. Anyone have any knowledge for me?

 

[cjman250]

I think you have to swap the gauges out with one from a v8

 

[sewlow]

http://www.gmt400.com/forum/showthread.php?25131-More-Escalade-Clusters-with-LEDs

 

[88 Z28 Guy]

So a V8 cluster will fix the tach and speedo but what about my gas gauge?

 

[cjman250]

Maybe I have no experience with a swap like this. My gas guage moves around a lot to but it's in the ball park

 

[skylark]

Just got finished doing V6 to V8 swap and now my gauges are acting funny. Tach and speedo are way high. Also my fuel gauge is pegged straight to the right. Anyone have any knowledge for me?

Knowing what year you swapped to and from would help here. The computer on the 96 and up trucks controls the tach signal, speedo and the fuel. I am assuming 96+ here, if your truck has different gears than the one that the donor came from the speedo will read off, the cluster is looking for V6 pulses for the tach the V8 has 25% more pulses at the same rpm. The fuel gauge might just be a simple pin in the wrong spot when a computer was swapped.

 

[88 Z28 Guy]

K let me give u the full history. Both my truck and my neighbors who I bought the swap from are 97. His truck was originally a 4.3 auto truck like mine. He did the swap but had ECU problems which made him set the truck aside years ago. I don't know what year harness it is but it does have the 5 plugs on the ECM so I assume it would have to be 96 or early 97 because I believe late 97 and 98 have only 4 plugs. I did notice 2 differences in the harnesses. There is a square 4 pin connector underneath the brake booster that has no plug to go to it from the V8 engine harness. The wires from the empty plug go down the driver side frame rail so I assume they have something to do with the fuel gauge. Also behind the glove box there were 2 connectors and a black box that was wrapped in foam. The new V8 harness does not have this black box. The main problem with my speedo being off is my tires I was planning on fixing that later on with 411 swap. I plan on getting a cluster from a V8 truck soon to solve the tach issue so my main problem is the fuel gauge.

 

[skylark]

If you do the 411 swap it can be changed to use the V6 tach.

 

[Michael Salin]

K let me give u the full history. Both my truck and my neighbors who I bought the swap from are 97. His truck was originally a 4.3 auto truck like mine. He did the swap but had ECU problems which made him set the truck aside years ago. I don't know what year harness it is but it does have the 5 plugs on the ECM so I assume it would have to be 96 or early 97 because I believe late 97 and 98 have only 4 plugs. I did notice 2 differences in the harnesses. There is a square 4 pin connector underneath the brake booster that has no plug to go to it from the V8 engine harness. The wires from the empty plug go down the driver side frame rail so I assume they have something to do with the fuel gauge. Also behind the glove box there were 2 connectors and a black box that was wrapped in foam. The new V8 harness does not have this black box. The main problem with my speedo being off is my tires I was planning on fixing that later on with 411 swap. I plan on getting a cluster from a V8 truck soon to solve the tach issue so my main problem is the fuel gauge.

Did you get the fuel gauge to work?

 

[TechNova]

He was last here in Dec of 18 so he might not respond