Back again with my speedometer! However this time i have just decided to go the easy route and pickup a SGI-100BT, i have a few questions for anyone who has installed one of these on a 1991 factory tpi vehicle. First question is could someone possibly post a picture of their SGI setup without a buffer box? And last question regards wiring, i know which wires i need to run into the SGI however do i cut them before they meet the ecm or is there another way i should be doing this?

 

Are you using the ecm as a buffer or for tcc lockup ?

 

https://www.thirdgen.org/forums/elec...sgi-100bt.html

if bypassing the ecm buffer c207 brown wire at ecm pin b11 is output to speedometer.

 

Hey man thanks for the reply! My car was actually a TPI from factory so it has the buffer built into its ecm so it doesnt have one of those yellow buffer boxes and with all the hacked up wires i plan on just bypassing it as a whole, looking over the wiring diagram (ill attach below) if im correct wouldnt i just cut the yellow and purple vss signal wires at the ecm along with the grey wire that runs to the gauge itself from the c207 connector and connect them into the Dakota Digital box? Just wanna do this the cleanest way and not destroy and more of the wiring harness than the previous owner did. Below is the wiring diagram i am referencing thanks again for the help!

 

Correct the ip wire could be grey or brown. You can power the sgi from c207 the ecms a6 pink/blk wire.

 

Perfect thank you very much! Was actually wondering which power wire i could tap i to but you beat me to it! would one of the empty fuse slots marked BAT also work as a power source if i chose not to splice into the pink/black?

 

You would have to test the fuse box for a hot key on and run accessory power.

 

Your the best man! Thank you for all the help, ill update with pictures in the near future once i get everything wired up and working just incase anyone else ever wonders exactly what needs to be cut and where.

 

Hey man i actually somehow managed to come up with another question do you happen to know where the vss sensor wires enter the car at? Ive been looking on the diagrams and i cant seem to find anywhere where it mentions where they come in through. First idea was maybe around where the shifter is? Figured id ask before i go digging haha sgi come in tomorrow!

 

Should be in the pass through connector under passenger side kick panel.

 

Not sure of what you're saying here, buy I hope you're not intending to completely bypass the ECM from the VSS. ECM needs a speed input to control other things besides speedometer. If not then disregard.

 

Im first gonna try placing it after the ecm so i dont need to cut the purple and yellow vss wires from it however i have a carbureted engine in it now so if that also does not work then i will cut it from the ecm as none of my gauges are wired into the ecm besides the speedometer.

 

what ? Your going to hook on the buffered signal ?

 

Before i cut the two vss wires that go straight into the ecm by the passenger side kick panel yes, im gonna just try to recalibrate the signal right at the c207 as ive stated in previous past im not the builder of the car however i do own it now and i can tell that it absolutely has a different rear end
ratio so im going to attempt that first if that doesnt work im gonna assume there is some fault in the ecm somewhere as i believe the gauge cluster istself is good every other gauge works besides the speedometer and odometer. the speedometer does move a tiny bit once the car is started it just freezes in place afterwards, the car also drives and shifts just fine so i dont think it could possibly be the speed sensor as id believe id have a check engine light or code for it. Ive had this problem for over a year now and im either gonna fix it by recalibrating the signal at the grey wire at the c207 or i cut the purple yellow and grey vss wires at the ecm and sending them straight through the dakota sgi-100bt and to the gauge

 

The sgi can take an optical signal and give out an optical?

 

From what i was told yes, i contacted their tech support and i was told to cut the purple and yellow wires before the ecm connector and connect them into the sgi and then also connect the grey wire from the c207. Thats basically why i came here i wanted to make sure that was correct before i cut i to anything

 

I’d just hook it up magnetic pulse input optical output.

 

Which way would that be? Place the box after the ecm at the grey output wire and attemp to recalibrate the signal right there or should i do as the dakota digital tech said and and connect the yellow and purple wires into the sgi along with the grey wire that goes to the instrument panel?

 

As tech support describes. But I’d be concerned about tcc lockup with a carb. Tci makes a kit then ecm could be fully bypassed.

 

Taking that into note i probably will try and just use the sgi to recalibrate the signal wire (grey wire) thats going to the instrument cluster as i actually got two responses from two different techs over at Dakota Digital one saying he always puts the sgi after the ecm and then one telling me to put it before the ecm at purple and yellow vss wires+the grey instrument panel wire. As im going to need to disconnect the grey wire from the c207 either way i do it im gonna attempt the way that doesnt involve cutting the purple and yellow wires first.