Heat Rave R

I'm installing a device in my '82 NA 280ZX and was wondering where I might find a wire to get the signal for the speedo (Vehicle Speed Sensor) and the tachometer. As I understand it, the gauge cluster reads the speed via a spinning cable of sorts connected to the differential. Do I need to somehow tap into that device to get an electrical speedo signal, or can I get it somewhere else?

lifegrddude

If your ZX has cruise control, there's a wire on the ECU harness that is for the speed sensor, but I can't remember off the top of my head. Otherwise, there isn't an electric signal. If you have a factory service manual or a wiring diagram, you should find it.

John 82ZXT

icice9

Heat Rave R

i guess after the JDM show at the san leandro marina you decided to go get a 280ZX... rite on man... so what did you do with your prelude???

Heat Rave R

Hehe, actually, the old Z's had always been on my mind for years. To me, the 280ZX was the best compromise of the original's styling, but with some modern amenities. I've put the Prelude up for sale; I figured it's best to sell it while it's still "in it's prime". Since you live near a couple of my friends, you might even see me buzzing around one of these days if we don't see each other before the next car meet. ^_^ Actually, I'd like to ride in your ZX one of these days; I'm not sure if the way my car feels is "normal" or not, so a comparison ride would be perfect.

Heat Rave R

Thanks for the info. Yes, my ZX has cruise control, though it doesn't seem to work right now (the "On" indicator light is on, but nothing happens when I set the speed), so hopefully the cruise control doesn't need to be active in order to have that speed sensor signal flowing.

anlasak

The tach signal comes from the negative side of the coil with an in-line resisitor to drop the voltage to the tachometer.

At least on both my '81's and my '83 (all with the analog instrument cluster)

Heat Rave R

Currently, there's an MSD box hooked up with some kind of "sine wave adapter" attachment. Is that adapter performing the same function as the resistor you mention, or do I still need to get one (and what kind)? Would I be able to tap off the tach signal going to the factory tach?

anlasak

What model Msd set up do you have?

Heat Rave R

MSD 6AL, hooked up to that sine pulse adapter thing.

96WhiteG20

Hey all.. sorry to bring up an OLDER thread... but i just bought a 75 280zx with a 83 280zxt engine... The speedo and tach do not work, so is there anyway to at least attach the speedo to this new engine or should i be looking in junkyards for a 83 zxt dash?

lww

The speedo cable attaches to the transmission not the engine. If it still has the factory 4-speed tranny, you should have everything you need. I would check to see if the cable is attached to the back of the speedo.