1994 D21 VSS/Speedo problem

[bigdrummer67]

I am trying to figure out a problem with VSS/Instrument cluster problem. I replaced the VSS and speedometer/odometer worked fine for 2 days then it fluttered and quit totally. I checked the eccs code and it came up with #14 VSS. I checked the Instrument cluster and then found the CEL, ABS and the light next to it(can’t remember what it is)aren’t coming on. The three on the left. I checked the wires from the transmission harness plug for VSS to the harness behind the battery and it had continuity. I am no electrical guy. I also found an Instrument cluster in a salvage yard and it performed exactly like the original. The three most left lights never came on and speedometer/odometer won’t work. Tach, fuel, temp all work fine and the lights on the right side of Instrument cluster are fine. Oil,brake,seatbelt, can’t remember the last one. I cleaned all electrical connections in truck. Instrument panel, grounds, harness plugs, relays, everything I could get to. I am at a total loss. Can anyone help?

[Rev_D21]

Well first, Welcome to NICO! Are we talking 4cyl or v6?

Second I would start by downloading the factory service maunal for free from http://www.nicoclub.com/FSM/hardbody/1994/

Look on the EC section page 233 for VSS code information and EL section pages 38-41 for cluster circuit information. Follow the instructions that are provided. Report findings here. We can help.

[bigdrummer67]

Incredible resource! Thank you so much. I will be on it this weekend and I'll let you know how everything goes. Thanks again.
Oh yeah. 4 cyl. Sweet little truck except for the speedo.

[bigdrummer67]

Got to go thru Manual and run tests on wiring and VSS. Everything tested fine. Had continuity and power from ECCS plug to relay, to instrument cluster. I'm at a loss here. I guess that both instrument clusters are damaged. Check Engine Light bulb was blown but it seems to function normally. Computer still throws code 14 VSS. I guess I need to find another cluster? Love the truck, tho!

[Rev_D21]

I'm not so sure it's the cluster since the VSS is mounted to the transmission. The clusters are known to go bad on these trucks but so do the speed sensors as well. Makes me wonder if the gremlin is on the VSS to ECM path. These trucks are old enough for the wiring to become rather crispy so breaks and shorts are common.

[cewrightiii]

Same problem here...95 D21...checked VSS and all wiring per FSM...if you figure yours out let me know!! And if I find something i'll let you know!

[95Oldbody]

I have a 95 Hardbody V-6 5spd 4X4 with same issue. Speedo quit working. When I replaced vss, the old one did not spin freely and did not generate a signal when I tested it, so I figured it was the sensor, but to no avail, the speedometer is not working.
I pulled cluster and looked it over and tightened brass screws.
Does anyone know of a way to test the cluster?