wait 4 me performance harness + autometer gauge

[crustysack]

I have an 02 LS1 going into a 65 GTO, I have had wait4meperformance do the engine ecu+wire harness can anyone tell me if I can directly hook up the tach output wire from the ecu to a Autometer Phantom gauge or do I have to get the 3 wire adapter. Electronics is NOT my strong point:confused:

[CarlC]

The gauge should work OK but it must be set in the four cylinder mode.

[crustysack]

thanks the wire is labeled 4 cyl tach output- can anyone give me the facts why the signal is 4 cyl?

[Stoker420]

get intouch with Jesse at wait for me and I'm sure he will let you know why.

[crustysack]

Im saving up to ask him real questions, I've already spoke with him a couple of times about install questions, he is most helpful and plenty patience when it comes to an electrical novice like myself. Just thought someone on the forum would know why the motor puts out a 4 cyl signal

[dhutton]

I think the answer is that the factory GM tachs use the 4 cylinder signal. Nothing more to it than that.

Don

[crustysack]

tks Don

[LSXfan]

must use "4 cyl 2 pulse" setting for Autometer electronic programmable tachs

[Z06vet]

I know this is old post, but I have the phantom tach & there is no switch 4-6-8 cyl. There are 2 small gauge wires looped out of the grommet in back of tach. I was told on older tachs one or both need to be snipped to get 4cyl mode. Can anyone confirm this?
Scott

[Mudweizer]

Leave wires alone for 8 cylinder, cut the brown one for 6 cylinder, or cut both for 4 cylinder.

[CreepinDeth]

You'll also need to splice in a 4.7K resistor with a 12V power source, or the Tach won't read.
I forgot the technical term for this, but that's what I had to do.

My LS1 harness & computer in my 78z were done by Speartech.
Guages are Autometer Cobalts and yes, 4 cylinder setting.

https://static1.pt-content.com/images/pt/2010/11/Tachwiring-1.jpg