Irratic speedometer - '97 GTP

[id97gtp]

Some of you know about my speedometer that sometimes works, sometimes doesn't (the signal from the VSS to the PCM is fine, just the signal to the cluster is messed up) some of you have even had your hands into trying to figure out what the heck is going on.

I have great news --- problem solved today (after almost 4 yrs & 2 dealerships attempts at it) at our IdahoClub3800 Mod Day! Thanks to Paul and his brilliant troubleshooting skills!

He tested the wire from the PCM to the relay and it was fine, so he started looking at where the mass of wires enters through the firewall --- turns out it had been rubbing on the power steering line (for quite a while judging by the nickel sized patch of wear).

Pulled it apart to get a better look and sure enough the green wire we were tracing was worn almost clear through - under acceleration it must have been making contact, then when the weight shifted forward again, it lost contact causing the intermittent readings. Paul saudered in a splice, put on some heat shrink stuff, retaped it, added the harder plastic wiring cover and zip tied it away from wear sources. Works great now!

Guess the moral of the story is to check out the simple stuff and rule it out first before pulling clusters, etc.!