94 D21 tach and speedometer dead

[Superdav]

First I got to say I’m glad I finally joined this forum, I used to just look but when I needed it, it’s worked and people helped me fix two problems, now I’ve got speedometer and tach issues to settle, after that I’ll start a new thread on heat/ac parts if I can’t find something here.
The speed sensor is physically broken and unplugged so I know that’s a problem, bigger problem is it will not come out. I haven’t tried anything other than using my hand but will get deeper next chance I get. I’m not too concerned with it at the moment but it is a pain having to use my phone for a speedometer.
Is that related to tach problems? What operates the tach?

[VStar650CL]

The tacho on a '94 VG gets a square wave signal from the ECM on a White wire, pin 33 at the cluster. Start by seeing if you have a "middle voltage" (probably half the battery rail) there with the truck running. If so, the problem is in the cluster and not the signal. If not, the ECM gets its signal from the power tran-sistor (PTU), and there's a 2.2K dropping resistor in between the coil/PTU and the ECM which will kill the tacho if it's open circuit. That would be the prime suspect. Should be located around the driver's wheel well IIRC.

The speed sensors have an o-ring that's located about 1/4" down the bore of the hole, and the area outside the o-ring can cake up with corrosion. They don't usually seize hard enough to break the sensor housing when twisted, but to be safe, I'd give it a long soak with WD40 before trying to remove it. Crud on the bore wall can also make the o-ring very stubborn, so expect to do some twisting and prying on the housing to get it loose.

[Superdav]

The tacho on a '94 VG……..

Should’ve mentioned I have a 4cyl, is it the same?

[VStar650CL]

Basically. The only difference is that the VG ECU gets the tach signal from the PTU, the KA gets it direct from coil-negative. IIRC the wire color and position are the same at the cluster and both have a dropping resistor.