I purchased another speedo (instument cluster) and got the same results. Speedo does nothing! What can I do to determine the speedo issue? Please Help. History: I purchased the car with the broken speedo. The car was converted from stick to automatic. I recently had the transmission overhauled.

 

is this a tbi or tpi v6 or v8 ? Have you checked to make sure there is a vss on the transmission ?

 

The car is now carb 750, V8 383. I could check the vin to see if it was originally a V6.

 

the 8th digit is the engine

 

the eight digit in the VIN has an "E".

 

vin E was a L03 tbi, the vss 2k ppm signal purple and yellow wires goto a vss buffer and from the buffer out to the speedometer 4k. The buffer could be located next to the ecm or bye the ip.

 

Ok, not the easiest asnswer, but what I did to fix mine was get an OBDI scan cable, and check to see if the computer saw a speed signal. One car I fixed saw a signal, so bad speedo, sent it to the shop. Other one did not see a signal, so bad speed sender, replaced it. Since you swapped a known good speedo in, it must be the sender on the trans. As asked above, did you see if it is hooked up?

 

i had the same issues
check out this thread if u need additional help

https://www.thirdgen.org/forums/elec...l-sgi-5-a.html

 

Yes, I plug in the wire at the transmission sensor. So Black91BAC you think it could be the sensor at the transmission? Thank you.

Tunedperformanc: You think it could be a bad buffer? Thank you.

 

will will need to see if the buffer is getting a magnetic pulse from the vss you can put the car on jack stands or drive it with leads hooked to the vss wires and see what the output it. Check power and grounds of the buffer.

 

Tunedperformanc, Where is the buffer with VSS input wires locacted?

 

Berlyn0963, Swapping your V6 to V8 caused your speedo to die?

 

post #6 , The sgi-5 can be used to convert the wrong vss signal or changes in rear end ratio,tire size change or ecm engine swaps.

 

 

tunedperformanc: Thanks for the diagrams and pictures. I will perform some testing tomorrow.

 

TunedPerformanc: I found the yellow PED Module (under dash and left of the steer wheel). It had a number of 12077849 on the yellow cover. It had green, black and yellow, gray, black and white wires going to it. I will identify the wires at the Transmission VSS. I could not test because it was raining today. Will test tomorrow.

 

the 12077849 is a module for the air bags, The module you are looking for is a little bigger with the numbers 25071437 on it.

 

TunedPerformanc: I can't find the VSS buffer. Which side of the dash is it on?

 

I have seen vss buffers on the ecm bracket under the dash on the passenger side and under the dash on the drivers side I'm not sure what years are located on witch side. I am of limited use to you tis weekend im on super slow dial up for the next 2 days.

 

I do think the wires from the vss went through the body connector bye the master cylinder i think that is c100.

 

I found the VSS Buffer on the passinger (right) side. I tested the VSS input voltage and found no voltage. The VSS is bad.

 

before you buy a new vss I would pull the vss and look at the drive and driven gears. You can lookup the standard motor products sc12 53mm diameter sc40 22mm od. If you enter these in ebay you might find a reasonable price.

 

I pull the VSS and it does not match the 1992 Camaro VSS for 700R4. The VSS I have was found under Chevy silverado 88-95. Now, I'm concern whether it's compatible with my 92 Camaro ECM?

 

So it is a magnetic vss ?

 

Yes, I think so. It is about 2"1/8 wide. the part that goes into transmission is black collor with what look like a magnet.

 

Maybe the cheapest way to correct what the last guy did was to goto the junkyard and get a drac. You will need to recalibrate it for tire size and rear end ratio. Im not positive but I think all the outputs are optical so the ecm needs a 2k signal and the speedometer needs a 4k ppm signal.

http://www.tbichips.com/drac/

 

 

Just guessing you have a tci or toggle switch for tcc lockup, you would just hook up the drac where the buffer is c9 switch ign, c8 ground , 40ppm input from vss to the drac the high side is yellow wire the low is the purple wire. The output of the drac would be c4 to the speedometer the green with black stripe wire out of the buffer. In the 88 -92 trucks the drac's are behind the glove box insert.

http://www.jagsthatrun.com/V8-chapte...ed-Sensors.pdf

 

Tunedperformanc, Thank you? I'm overwhelm. Do I look for the drac on Silveraldo?

 

I would look for the drac and the wiring pigtail on a silverado 2wd and even snag another vss didnt sound like you got any blip of a ac reading from it.

 

let me know if you have issues wiring it in you only need to hook up 5 wires from the drac. You might want to get it working then reprogram it bye the jumpers or instal a dip. since you pulled our the vss make sure there is a reluctor installed on the output shaft of the transmission.

 

Would a Dakota Digital Sgi 5 Simplify this issue?

 

you might want to call dakota digital but looking at the installation manual it does not say it will go down to a 40ppm input.

http://www.dakotadigital.com/pdf/sgi-5c.pdf

 

When you say 40 PPM do you mean 40K PPM? And the right VSS for this car puts out 2K PPM.

 

Your correct the car should of had a 2k ppm vss to the buffer , The tbi truck is 40 pluses per driveshaft revolution.

 

Dakota SGI-5 techs said it could handle the 40K PPM. I ordered the SGI-5 today and should have it Tuesday. Please stay posted.

 

How would you wire in the Dakota SGI-5? I know, I have to find a power source and ground for Dakota SGI-5. I plan to route the VSS Yellow wire into the Dakota SGI-5. SHould I input a 2PPM Dakota SGI-5 output into the VSS Buffer. I'm expecting the Dakota SGI-5 on Tuesday.

 

you can use the hot in run acc power from the old buffer and the old buffer's ground. The output wire from the old buffer green/blk will be a 4k optical output of the sgi-5. You will have to post your tire size rear end ratio to figure out what the magnetic input will be. I believe like I said in earlier posts the tbi truck is 40 pulse per revolution on the drive shaft. on post #33 I put a link to there installation guide. The purple wire of the vss is ground The yellow is the input. looks like switch 3 will be on.

With 4.11 gears and 25 inch diameter tires (an S-10 truck for example), this will put out about 133,000 pulses per mile. With 2.73 gears and 27 inch tires, this will put out about 82,000 pulses per mile.

 

did you get it ?

 

Yes, I installed it today following your recommendations and it powered right up. I set switch 3 on and use output 4 for the speedo input. The Speedo did not show any input until the trans shifted and the Speedo peg out at 110 MPH. After 3 to 5 seconds it return to zero MPH. I contacted DaKota Digital and they set both switches 3 and 4 to on. Also, they changed output from 4 to 5. The speedo at 20+ MPH show action. The Speedo is 20+ miles too fast. DaKota Digital advise use their Calibration process to calibrate SGI-5C. I will try to calibrate tomorrow. I'm concern that the speedo don't show any input until 20+ MPH and using output 5 for 2K PPM. What do you think?

 

I would follow there directions I dont know the range of the calibration buttons but the speedometer is expecting a 4k ppm optical and if you go with a 2k ppm optical output it will be 50% lesss and im not sure all the adjustability the sgi will give you.

 

Tunedperformanc you are great! Thank you. This forum is fantastic! I've learn so much from you and the forum. I use Tach issue fix and now my tach work perfect.

My car has a manual switch that run the external fuel pump and radiator's electric fan. Do think I can run these from the ignition switch power source?

 

you can wire in a relay and it would be turned on off your ignition switch a switched power.

 

the fan you can do the same thing or better yet look into a derele adjustable fan controller.

 

Where do I find a relay, at auto parts store? Today, I successfully calibrated the speedometer with the SGI-5C interface. Thanks again. Does anyone know which fuse the Cigarette lighter is on?

 

I believe the Cigarette lighter is labeled courtesy 20 amp
You can use a bosch 5 prong relay

 

just curious what were the setting to get it dialed in ?

 

Thank you!!!
It was very simple after the speedometer is responding to the SGI-5C. The SGI-5C calibration process is simple to follow. For my solution, the SGI-5 setting was at the very top. I simply had to reduce the coarse settings two times and complete the calibration by reducing the fine settings one time. Accuracy of the speedometer was verified with the GPS and comparison of another vehicle's MPH. Thank you again!