I'm having problems with an Autometer Speedo (Phantom series, 5889) that I have installed in my '95LT1 / 4L60e powered '76 Vette (F-body PCM).

Here is an e-mail I just sent to Autometer, but being that it's now Friday night, I don't expect to get a response until at least Monday...maybe others can help?

>> I'm using your Phantom series Electronic Speedo (5889) in a vehicle utilizing a '95 LT1 engine / 4L60e transmission (automatic, 4-speed) w/ a '95 F-body (Camaro / Firebird) PCM...

Per the instructions provided, I spliced into the VSS circuit (coming FROM the VSS - circuit A32, yellow wire) and connected into "Sig", then from "Out" connected back into the VSS wire going TO the PCM. After calibration, this worked for a few miles, then the transmission started shifting improperly (wouldn't come out of 1st, wasn't in the correct gear even if shifted manually, etc.) I bypassed the speedometer and connected the spliced wires from the VSS back to the PCM, but that didn't resolve the shifting problem. I ended-up having to replace 2 shift solenoids in the transmission before things were back to normal. Not knowing if that solenoid incident was caused by a problem w/ the speedometer or just a coincidence that it happened shortly after hooking up the speedometer, I just tried the connections again and same thing...no shifting out of first. I immediately stopped to avoid further damage and bypassed the speedometer again (all is OK w/ the transmission), but would REALLY like to have the speedometer functional.


I also have a "VSS OUTPUT" signal (circuit B8, green/white wire, in the F-Body PCM) and I tried connecting that TO "Sig", but get no response from the speedometer.

Connecting to either "VSS" or "VSS OUTPUT," the speedometer correctly goes thru it's calibration process (goes to MAX when holding reset button while starting, etc...), then no further response is seen once the process has been completed.

Is there something I'm not doing correctly here?

Hopefully I provided enough detail...PLEASE let me know if any additional information is needed.

Thanks for your assistance...have a GREAT weekend.<<

Thanks!

 

the speedo won't recognize the buffered signal from the computer. It has to be connected directly to the speed sensor. I couldn't tell from your post but did you cut the yellow wire and run it to your gauge or did you piggyback off of it? According to autometer, you need to connect to the signal wire coming from the speed sensor and then calibrate the speedo. The computer still needs the signal though to properly calibrate everything.

 

Actually, I've tried both: Cutting and Piggybacking.

When I CUT the yellow wire (VSS SIGNAL), the path was as follows: FROM the VSS in the tranny TO the "Sig" terminal of the Speedo, FROM the "Out" terminal of the Speedo, back TO the PCM.

When Piggybacking, the path was: FROM VSS to the "Sig" terminal AND TO the PCM (I just "T"-ed into the VSS SIGNAL wire to the "Sig" of the Speedo)

How do I get the correct signal from the VSS to BOTH the Speedo and the PCM? According to the dirctions supplied w/ the speedo, the method I described above for "CUT" is what is recommended. It states that connecting from "OUT" back to the PCM provides the buffered signal that the PCM needs.

If the VSS is supplying a "buffered" signal to the PCM, and the Speedo can't accept a "buffered" signal...is there ANY hope?

BTW: I contacted AutoMeter PRIOR to purchasing and was told my setup would work "fine"...BASTARDS!

Thanks...

 

that doesn't make any sense. The computer doesn't get a buffered signal from the vss so why would the instructions tell you to send a buffered signal from the gauge? Very interesting. I am actually in the process of installing an electric speedo in my car too and have actually wondered why they would use the full signal from the trans. I too called and talked to a tech support person that said the speedo would hook up to a stock gm sending unit. We'll see.

 

OK, Autometer replied... they said I should just "T" into (piggyback) into the VSS SIGNAL (yellow wire) and connect to "Sig" (leave the "OUT" terminal alone). They stated that if this method didn't work, let them know the manufacture date of the speedo.

Since I have tried this method already (and experience shifting problems when connected this way) it looks like I'm ripping out the dash again to get to this "date code"... I don't think I captured it in any of my digital pics

Might be a day or two before I get to it, but will post what Autometer suggests after I give them the date code.

To be continued...

 

OK, popped-out the dash panel and the wire going into "sig" just about fell off, so put back in securely (it does fit tight, so I may have pulled on the wire during install...don't think it vibrated loose).

Anyway, "piggybacking" the VSS wire into the speedo (nothing connected to "out") seems to be working fine! Don't know why the loose wire affected the shifting, but now that it's secure, tranny shifting fine...???

Thanks for the replies