Speed Sensor Wires - not used?

[IowaBen]

I'm working through the wiring, trying to verify all the connections.

For the 2 speed sensor wires (Grey and Green) that have wires in the dash harness, Coil/EFI harness, and near the transmission: I believe that I don't need to use any of these wires since I have the Vintage gauges. I also have the Sniper EFI, which I don't see call for these wires either.

Just looking for confirmation from the experts here.

Thanks!
Ben

[michael everson]

You can remove them from the harness.
Mike

[Hacksaw84]

For the speed sensor wires, yes and maybe no (but probably not).

I don't think this is you but... the Gen 1 Coyote (when using the control pack from ford) needs those wires for the computer/tune to deal with stalling when slowing down. You need to wire in a separate ford speed calibration module between those two wires and the PCM. I believe the Gen 2 and 3 solved it in the control pack itself. The wires needed are from the sender itself, not the dash harness to a speedo. So nothing related to the GPS based speedo but used in the car.

Probably not your situation but might matter for someone else.

[edwardb]

This is pretty random, but here's another situation you might need the speed sensor wires even with GPS gauges. The Tremec T-56 has a solenoid driven lockout for reverse. One of the common approaches is to use a module driven by the speed sensor that locks out reverse when the car is in motion. So even though the sensor signal isn't needed for the speedo it is needed for the lock-out module. Have that setup on my Coupe build and it works great.

[JohnK]

That's both pretty cool, and pretty funny that you need to feed the transmission a signal from... the transmission in order for the reverse lockout to work. You'd think that the T56 would know when the car is in motion all on its own, no? ;)

[edwardb]

That's both pretty cool, and pretty funny that you need to feed the transmission a signal from... the transmission in order for the reverse lockout to work. You'd think that the T56 would know when the car is in motion all on its own, no? ;)

Yeah, I guess it's a matter of perspective. The T56 does know when it's in motion and uses the speed sensor to tell you. The module I mentioned uses that speed signal to know when to send +12V to the reverse lockout solenoid. Some use a lower tech approach like a button or lever on the shifter. Or even tying to the brake light switch. I guess your thought is the function should be internal to the T56. But we're getting a little off topic.

[HerculezJT]

That's both pretty cool, and pretty funny that you need to feed the transmission a signal from... the transmission in order for the reverse lockout to work. You'd think that the T56 would know when the car is in motion all on its own, no? ;)

T56s and TR6060s are just simple minded workers that need to be told what to do, like what gear to be in. Do as your told and dont think for yourself damnit :)

[JohnK]

Yes, sorry to derail the conversation. I totally understand - just thought it was a bit amusing.