speedometer wiring for 01 5.3 into 91 gmc k1500

[scotte]

just finishing swapping a 01 5.3/4l60e into my 91 gmc 1/2 ton

being a 91 the truck has its drac/vssb built into the cluster (not in a seperate white box)

meaning that the cluster expects to see the ac waveform from the 40 tooth reluctor wheel in the tranfercase

the problem is that the 411 pcm also expects an ac waveform from the 40 tooth reluctor wheel

connecting both to the same vss sensor results in neither receiving the signal


is there a solution to my problem (besides swapping speedometers I consider that a last resort)

[cpwire]

Believe it or not, you should be able to split the signal between both items.
If you wire it in and they don't work, then switch the wires going in to one of the 2 (either ECU or speedo) and see if that doesn't fix it. I know polarity shouldn't matter, but I think you'll find that it should work.
Worst case, you may need a module from Dakota Digital or something to run the speedo.

[twisted954]

I'm curious on this one too. I had my 89 up on the rollers and had to switch it into higher gear to get tuned but would like to tackle this issue. Does anyone have a pinout handy for the cluster? At this point I don't even care, it's more important that the transmission works right...I just dont know the wiring pinout so I don't even know where to grab the VSS signal from

[Chevy-Art]

Here is what I did on my swap. There are two wires coming the original VSS on the 700r4. One is Yellow (400 High) and the other one is Purple (401 Low). I spliced them to the LS1 pcm Purple/White (821 High) and Light Green/Black (822 Low). That got it working. Are you doing an LS1 or another Gen III/IV engine. If so the colors may be different. Hope this helps.

[twisted954]

Personally I am doing a 2000 5.3...I DO have the complete pin out for the ECU so that is not something I am worried about...I AM wondering where you ran the wires from/to and how did you keep your gauge operational? DID you tap into the existing wires leaving the gauge wiring intact? OR did you just say screw the speedo? OR did you do something else?

[scotte]

i will know later this weekend if swapping the polarity works (I've been to busy to work on my truck)

twisted454

I AM wondering where you ran the wires from/to and how did you keep your gauge operational

oil pressure sender just works i connected the brown wire from c100 in the 5.3 harness to the wire going to the drivers side bulkhead

tach works after changing settings in computer to 3 (high and low) and connecting the output wire (AT C100) to the white wire in the connector inside the pass side dash

the coolant temp sensor you need a 3 wire sensor out of a 98 firebird and to rewire it to the 2 wires in the 5.3 harness and the third wire connects to the truck

volt gauge just works (I taped up my alternator control wire so the warning light is off as I prefer pcm alternator control)

there is a bunch more info on the site if you search for it but if you get stuck on a wiring/computer issue feel free to pm me i run a 2 bay garage (have access to wiring diagrams/pinouts)