Hello, I have an 88 trans am, I did an ls1 twin turbo swap over the summer. I want my factory gauges to work. I am using a turbo 400 trans now. How can I get the electric speedo to work?? And in the holley wiring harness, there are wires where I can hook the other gauges up, I just need the wire diagram for the plug that plugs into the back of the cluster. Hopefully someone can help me.

 

I find it hard to believe no-one in this group knows the answers to my questions

 

You need a VSS to get your speedo to work. There are any number of ways to get one, or make one work. Something you could figure out with a little research, it has been covered before.

What Holley wiring harness? You haven't given any details for anything, so how are we supposed to help you? What gauges are you trying to "hook up"?

 

1988 trans am, electrical plug, but its not digital. I'm running a turbo 400. I know they make adaptors to go from mechanical to electrical, but yet I cant find what pulse per revolution these speedo's are. And if I use say like a early 90's chevy truck vss, do they have the same plug in or do I have to cut and wire, ??? Thx for any information

 

Oh holley ls1 wire harness with the holley dominator ecu. THX

 

What you're trying to do is not clear, other than get your speedometer to work. I don't know what you're trying to feed into the Dominator? Other than your tach nothing else is coming from the Dominator system. Oil comes from a sender on the engine, get a factory sender for your year and an adapter for the feed port. Temp comes from a sender, get the correct one for the year and an adapter for the port in the head, or get one from a LS 4th gen and use that for your factory gauge.
Speedo you need a signal and you'll likely have to adapt it to the correct pulse count, a Dakota Digital SGI-5 will do that.
If you look in the engine swap forum, all this has been covered ad nauseam

 

what is the correct pulse count? And is there a wiring diagram for the plug that plugs into those electronic speedo's? Thx

 

I looked at this Dakota digital box you talked about but doesn't say how this works, you also said I had to have a VSS, so is this taking its place?? I'm totally lost. Need more info, and I tried looking through this thirdgen.org forum thing and I don't think I know how to use it bc I cant ever come across anything I need to know, so sorry asking something that's already been asked, but ive never came across it here.

 

The Dakota Digital SGI 5 absolutely says how it works.
http://www.dakotadigital.com/index.c...rod/prd126.htm

"The SGI-5E Universal Signal Interface Unit can handle nearly all of your electric speedometer signal conversion and calibration issues. The SGI-5E can recalibrate a 2,000 pulse per mile (ppm) through 250,000ppm electronic speedometer pulse rates, either up or down. The SGI-5E is great for adjusting aftermarket and OEM electric speedometers on vehicles after changing rear end gears, tire sizes, or drivetrain changes affecting the speedometer.

The SGI-5E is used as either a signal multiplier (up to 16X) or signal divider (up to 125X), making this unit extremely flexible for almost any application. While the SGI-5E is intended to correct only the signal feeding the electronic speedometer, in many cases where a speed signal is shared or on a databus, the SGI-5E can instead correct the signal feeding the engine and transmission computers. For even greater flexibility, the SGI-5E allows multiplication up to 16x, taking an 8,000 ppm signal and converting to a 128,000ppm output, and includes a regulated 5V sensor output, allowing use of the Dakota Digital SEN-01-5 speed sensor. A built-in LED display and pushbutton switches simplify setup and calibration."

 

Get VSS signal, convert VSS signal to your speed, ???, profit.

This really isn't rocket surgery. Get a Holley VSS, get a DD VSS and convert them, or get a GPS speedo.

You haven't searched one bit. I got the answer you need in 5 seconds
https://www.thirdgen.org/forums/tran...o-hook-up.html

 

GPS speedo
http://www.dakotadigital.com/index.c...rod/prd837.htm

"The GPS-50-2 is also fully compatible with other aftermarket electronic speedometers. Offering a user selectable output of 4k, 8k, 16k PPM signals and a selectable signal type of a Sine Wave or Square Wave, the flexibility is endless. While the GPS-50-2 is not designed to control a shift computer or shift pattern of the transmission, it is capable of supplying a 54,400 or 128K PPM signal to supply an ECM to ease some of those unique transmission swap situations! "

 

1988-1990 3/4 ton chevy pickup with a big block and a th-400 used an electric vss which should match the ppm but I haven't looked to verify that yet. So in theory you could use the vss sender from that truck on you th400, but that depends what th400 you have. You may have to swap the drive/driven gears and the tail housing to use everything.

Or do what scooter said.

I've used the Dakota digital box before with good results, so that's an option if you use a basic mechanical to electric adapter on the Trans, provided your trans has a mechanical hookup

 

Well excuss me I don't know how to use this site very well at all, everything ive typed in the search bar doesn't bring **** up. ****ing rude people

 

Sorry, but you're the "rude" one. I gave options, told you to search, which you obviously did not do, then I gave you the answer. You could have searched the complete internet and gotten the same answer in just a few minutes. You know how I know all the stuff I know? I SEARCHED and then I read some more. And then I read more and more. You will find very few questions from me on this site because I READ, I never expected anyone to just give me the answer.

 

**** off