Ignition signal from engine compartment to tach...
Posted 30 August 2016 - 01:49 PM
Posted 30 August 2016 - 02:46 PM
Brown, green and red would be the VR sensor wires that run to the ignition module in the cabin. The blue wire from the coil negative terminal (through the ballast) is the tach trigger.
Posted 30 August 2016 - 03:20 PM
You need to add some detail. There are some considerations and some simple tests you can do. It's not even clear what you mean by nothing. Could mean no blue wire, could mean blue wire doesn't work. Could be the resistor fell out.
Posted 30 August 2016 - 04:59 PM
Posted 30 August 2016 - 05:17 PM
Do you know what the signal is? Did you measure voltage at the tach end of the blue wire? Have you looked at the wiring diagram?
Really, the basics are pretty easy with a meter. Get everything connected correctly, then you can focus on why the needle doesn't move. With a meter you don't have to worry about what the terminals look like.
Who recalibrated your tach, and is it the stock 1975 280Z tach? Are you using the stock 280Z harness connection at the tach? Aftermarket tachs can have different wiring schemes.
Posted 30 August 2016 - 05:27 PM
Posted 30 August 2016 - 05:30 PM
Posted 30 August 2016 - 05:51 PM
With the key On you should see battery voltage at the tach end of the wire if it's connected to the coil negative terminal as it should be. The 280Z tach just counts the voltage pulses on the negative post of the coil as the coil charges and discharges.
Posted 30 August 2016 - 06:09 PM
Posted 30 August 2016 - 06:28 PM
There's a tach output terminal on the typical HEI distributor from what I see on the old interweb. It's probably just a branch from the coil negative post. Easy to check.
Posted 30 August 2016 - 06:55 PM
I don't know what means. But, good luck with it.
I have a GM HEI system, module and coil, on my L6, using the 280Z VR signal. My tach doesn't work without a condenser on the negative terminal wire.
Posted 30 August 2016 - 07:08 PM
0 user(s) are reading this topic
0 members, 0 guests, 0 anonymous users