Another Tach Question. (Did search first!)

[trunknuts]

2005 5.3L (Tahoe motor) in a 93 Silverado. Got almost everything working so far. What I'm having trouble with is the Tach signal. I'm using an Auto Meter tach. I tapped into Pin 10 (white wire) on the green connector on the PCM. I also set the tach to 4 cylinder (2 pulse I believe). With the tach plugged in it moves ever so slightly when it first gets power. When I connect the "signal" wire to the white wire on the PCM nothing happens. The tach doesn't work. If I take the "signal" wire on the tach and repeatedly tap it to a 12V power source (simulating an AC signal) the needle does move around, up to 7k RPM. I've checked the ground and power sources with a digital multimeter. They seem fine. Does anyone know if the white wire on pin 10 still have the RPM output? Was there a change in '05 or earlier? I'm so frustrated with this. Any help will be greatly appreciated. Thanks again!

[NITROUS]

You need to change the tach resolution in the PCM from 6 to 3 or get a module from Dakota Digital to convert the signal. Who did your tune? Send it back to them and have the resolutiuon changed if you want to make things easy.

[trunknuts]

Thanks again NITROUS. I'll check out Dakota Digital. Wait4me Performance did the tune. I'll also contact them tomorrow and see what they say.

BTW... is this what I need?
Dakota Digital - digital instrumentation and accessories automotive and motorcycle enthusiasts.

[Chevy-Art]

I'll be doing this soon too, thanks for the info.

[RedHeartbeat]

That or you can contact BakerElectronix.com and get one of his adjustable resolution tach modules.

[trunknuts]

RedHeartbeat... is this the adapter you are referring to?
http://mysite.verizon.net/vze7erz1/s...files/atsd.pdf

Also, If I understand this correctly I need to convert the 4 cylinder signal to an 8 cylinder signal? Shouldn't the aftermarket tach be able to do this with the dip switches? I'm not arguing I'm just trying to make sense of this. Thanks again.

[RedHeartbeat]

You can use that to change the signal count to your tach module if you don't have a PCM program to modify it.

[NITROUS]

Ya, I forgot about Baker Electronics........They will probably save a little money over Dakota but the cheapest way is the resolution change with HPTuners or EFI Live.

[beater6.0]

i have a problem with my 98 and i have module could the tune cause it not to work i have tried a diffrent tach. and i do have the baker module.

[Wtfan18]

i have a problem with my 98 and i have module could the tune cause it not to work i have tried a diffrent tach. and i do have the baker module.

would this be an issue with a nelson made harness? and a manual tranny?