2-wire speed sender troubleshooting-step 1 mechanical test
2-wire speed senders (screw-on and OE integrated style) both generate an AC sine wave internally withoutany power being supplied.
One wire is connected to a good ground (keep the wire short) and the other to the speedometer. It does not matter which wire is which.
-You cannot split a signal from a 2-wire speed sender (have more than one item connected to it for example, one speed sender cannot operate a cruise control and a speedometer the signal strength will be degraded by 1/2).
-Check for mechanical engagement.
Remove the speed sender from the cable output on the transmission. Leave plugged in.
Turn on the key,using a drill, spin the sender shaft. You should see action on the speedometer.
YES I see action on the speedometer when I spin the drill. This means if you see action with manual spinning but not when the sender is in
stalled on the transmission that there is some sort of mechanical engagement issue. The sender is not being spun by the transmission.
- Check that the drive gear is in the transmission and spinning when tires are rotated
- Check that the drive gear square drive is not out of round. the spec is .014"x.104"
- on Ford style senders: Is the gear installed on the end of the sender? It was on the cable when it was removed.
NO I do not see action on the speedometer when spun manually