Hi all, Enjoy reading the posts when I have time. Really learn a lot. Now to the problem I am having with my electric speedometer. I have installed an 305 TPI out of a 91 Chevy IROC with a 700r4 tranny into a 48 Chevy pick-up. The wiring harness is aftermarket from a great guy in Texas, but I have lost his address. The gauges are dolphin, of course electric. The harness comes with a 2000 & 4000 ppm wires. The vehicle speed sensor is a 4000 pulse, but when wiring to the 4000 ppm wire, nothing happens. So I tried the 2000 ppm wire, still nothing. I assume the VSS is in proper working order since I have not had a trouble code come up for the VSS. The VSS from the transmission has 2 wires purple & yellow, these wires go to the ECM. From the ECM are 2 wires brown 2000 ppm & gray 4000 ppm. The gauge has 1 green wire to the pulse per min. wire (PPM). A blue wire (Dolphin says DO NOT HOOK-UP on the instructions). Red wire power. black wire ground. Seems pretty simple but I cannot get the gauge to move off 0. The gauge has power and a good ground. Can I come off the VSS directly to the speedometer? Can I test the 2 wires from the ECM to tell if they are power-ed up. Anyone had problem of this sort and figured it out I sure would appreciate any help. Thanks all
Try givin these guys a call : http://www.affordable-fuel-injection.com/store.php?crn=208&rn=421&action=show_detail And you may also wanna try calling Painless : http://www.painlessperformance.com/webcatalog/largeview.php?SearchField=60115 I'm pretty sure either could point you in the right direction. Good luck.
I may be wrong. However, won't something have to run out of your transmission in order to read your speed? I've never heard of being able to just run a wiring harness to your speedometer. I had to buy an electric reader thing that went into where the speedo cable usually runs, and then it had a wire that went out to the electric speedo.
i'm not really following what you are saying , but here is what i would check for: is there power going to the gauge AND sender? are both of them grounded?
That's the VSS he's talking about (Vehicle Speed Sensor) it runs off trans. pressure to convert mechanical movement to an electrical pulse or signal that the computer sends to the guage. Don't be so sure about the lack of an engine code 475wls1 it will depend on the computer and how the system is programmed. I would check for signal directly at the VSS as per '91 IROC diagnotics and go forward from there.
I'm pretty dumb on this stuff but a buddy of mine had a problem kinda like yours in his car. It was not TPI and had a TH350 but had electric Speedometer (VDO). The pin in the trans was not the right length, can't remember but think it was too short, he changed out the pin and it worked after that. I bought a new set of VDOs earlier at Knoxville and the Vendor threw in both lengths of pins. Iwill be running a 700 in mine. Please be easy on me if this was stupid. 48 Poncho
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