rb25det Autometer shift light hookup?

[rb25drag]

ok I have a autometer shiftlight with the rpm dial on the back. I need to hook it up to read an RPM signal. I currently have my AFC hooked up to the ECU and reading rpm's but I am unable to get my shiftlight to read the signal. I was told I needed a converter from autometer. So I bought one (75$). But im still unable to get it to read a signal. Any information?

[Darius]

ummm should only be one tach output wire on the ECU that you need to find. very simple...can't remember if it is y/L? or y/r? I'm too lazy to go look in the FSM right now. All the shift light needs to know is how many cylinders the motor has.

[rb25drag]

Ya I found the tach signal wire. Thats wat I have my AFC hooked up to. But when I splice in with the shift lite signal wire It reads nothing and it also kills the rpm on my afc. So I have tried it with and without my AFC hooked up but nothing. Is there a wire I can splice into from the CAS?

[Darius]

Not really because the CAS only sends a signal at 0 and 120 degrees of cam turning, I believe. The ECU interprets the signal from the CAS and sends its output to the gauge cluster. It sounds to me like something is wrong with the wiring to the shift light that is grounding the tach signal so that it goes to ground rather than onto the AFC.

[rb25drag]

Sorry im confused about the wiring? wats interfering with the ground?

[Darius]

Ok first things first. Does, or did, your gauge cluster work properly after you installed the AFC?

[rb25drag]

Nothing works completly correct on the gauge cluster except my gas gauge. The MPH is way off and the stock tach has never worked. I never had it calibrated. Didnt plan on using any of it besides a tach. I always have used the AFC for a tach,.

But when Im going down the track I dont have time to look over and see wat RPM Im at Digital! . I would Rather get this shift- lite working so all I see is a flashing light.

[Darius]

So you have a SOHC S13?

I don't know much about the cluster adjustment. Talk to CarlH about that. He'll adjust it for you for cheap.

Since the AFC is showing the correct tach reading, there is obviously a signal through the wire. Do you have the tach signal light properly grounded? If it isn't grounded well enough, the tach signal will not go to wards the tach light, but instead towards the ground in the AFC.

[rb25drag]

Ya its the SOHC s13 cluster.

Its grounded to the chassis, I have tried unhooking the AFC completly and it still will not pick up the signal. If I have them hooked up at the same time the AFC wont read a signal either. Its been a while since I have messed with it. But will autometer tachs read the RB rpm signal? I have the converter if needed.

[Kansei240sx]

Dont splice into the SAFC's signal. Splice it down by the ECU and run a wire up from there. Also, even though it says to run the grounds and power off the ECU, dont. Run the power wires from the tach and safc to an automotive relay that get its signal from the ACC relay, that way you're not robbing the ECU of voltage that it needs.