Stamey

I have this 91.5 I just purchased and the speedo doesn't work. I have not pulled the gauges from the dash yet, but I have look under the truck. It appears that the speedo cable is missing, as I see where it connects to the trany, but no cable anywhere.
I have looked around the firewall and cannot even see where the cable would go through.
This brings me to the next question, am I even supposed to have a speedo cable? I'm not sure when they went electronic but I wonder of this is the case here, that the tranny in the truck has been changed, from an older truck, and the speedo gear is left in there, with the cable atach point, but this truck requires electronics. I have seen no extra plug hanging under the truck, but then again, the fuel gauge is wired with speaker wire, so who knows.

Thanks,
Chris

dodgenstein

You should have an electronic speedo. There is a VSS (vehicle speed sensor) that threads on to the output where a cable would normally go on the trans. If it is a getrag, there should also be a 90 degree adapter/ratio reducer on there.

wannadiesel

Look on the trans crossmember, it may have just fallen off and is laying there. Wouldn't be the first time.

Stamey

Yes, it is a 5-speed. Are you saying that the cable connection I see there now should have an adapter that fits on it that makes the speedo electronic? this would mean that I do not have to remove the piece that is in the tranny, just add something to the outside?

Thanks,
Chris

wannadiesel

Exactly. There is a 90 degree ratio adapter on the speedo output, the VSS threads onto the adapter. The VSS will thread directly onto the trans, but the speedo will be off by 15-20 mph.

Stamey

OK, so I looked and found nothing in the crossmember. Now I wonder about where the wires come from for it. I suspect it's those 2 raggedy wires that are different lengths (ripped off) that come out of the same wire bunch that the reverse light's are on. The reverse lights are hooked up, but there are 2 extra wires.....
So, tell me whan I need to buy for this thing. Just a VSS and the wire pigtail?

Thanks,
Chris

Stamey

This what I need to get?
http://cgi.ebay.com/ebaymotors/90-91...spagenameZWD1V

Thanks,
Chris

Chrisreyn

Chris, thats it! or actually part of it..
that is the VSS, but you may also need a Gear Ratio Reducer.. that is a dealer only part. i am not sure what differentiated the two, but some models used them and some used the VSS only. You dealer parts guy should be able to pull your vehicle up by VIN and tell you.
Unfortunatly the Gear Reducer is around $80..
teh wayit goes to tgether is there is a threaded nub on the tranny( the drive gear housing) the gear reducer threads onto it, and the VSS onto the gear reducer..
the gear reducer looks like a little rectangular box with off set threaded nubs..
BTW Napa sells the VSS for about as much as that one...
The speedo sensor wires should be in the same bundle as the reverse switch connector, if you look in the "stickey" , the wiring diagrams for a 91.5 just happen to be there!.. it will give you the correct coding on the wiring to hook it back up.

Stamey

OK, fijnally hunted down all the parts. I found the speedo gear in the tranny was busted also, and the threads on the pieces that the gear ride in wear all messed up too. I found a great guy on Ebay that hooked me up with the gear and housing cheap.
Got that in, then installed the VSS to the housing and installed the 40.00, yes, I said 40.00, plug from Napa, which I spliced into the dangling wires bundled with the reverse light wires, and now the speedo works again.

Thanks to all for the information on this.

Chris

fanbrain

Do you have part numbers and info on what to look for?

Stamey

For the plug, which is the same the for the oil sending unit on my 96, is Napa Echlin EC165.
For the speed sensor, Napa Echlin VSS100.
What I found, after forgetting that I bought the VSS from Napa and buying one off Ebay, was that the Napa VSS comes with a pigtail that has the pplug included, so you can cut off the other plug and wire it up to your existing wires, if your plug is missing like mine was. DANG!! This means I spent 95+ bucks for those 2 parts, when I could have just bought the Napa VSS for 60-something bucks and been done with it. Live and learn.
I found the speedo gear and housing for it on Ebay, from user ID: silverado1116. This fellow helped me out a lot.

Chris