Jump to content
SAU Community

Recommended Posts

Hey Guys,

im installing my Apexi RSM today and want to get the Apexi shift light setup also. there isnt a direct plug for it so i gotta splice it into the white RPM wire. therefore im thinking i need to use a relay or somthing?

any ideas guy? someone else has asked the same question a while ago but didnt get an answer.

the shift light has a plug on it but im guessing its for a gauge not an RSM.

The rsm has one triggered output. Use that output to trigger a relay, and the relay to power the shift light. I can't remember if the rsm output is -ve or +ve triggered, so you'll have to work that out yourself. I did this for a mate, in his 33.

Not sure why you need to splice it in the rpm wire, as the rsm has a output wire. You then program the rsm to trigger that output at a certain rpm.

hey "AL" yeah i figured it out thanks mate. And its -ve triggered.

easy job but would have been easier if i have the english instructions.

lots of fun with the multimeter anyway

  • 3 years later...
  • 2 months later...

Sorry to dig up an old thread, but saves me from making a new thread on the same topic lol

I've got the Apexi shift light and was wondering what relay people have used for the shift light and what do they reccomend? I typed "12v relay" into Jaycar and it came up with 20 pages worth of different types of relays so I'm a bit lost to be honest. Also, WTF is a relay anyway?

2 choices.

1. Go to Supercrap Auto..... Buy normal Hella or otherwise typical blue relay with or without fuse. Live with it clicking every time it activates.

2. Go to Jaycar. Talk to counter geek. Buy suitable solid state relay. Won't need to be a big expensive one, as shift light current won't be very much.

Thanks for the reply fellas.

Clicking won't bother me that much as the car would be on full noise anyway by the time the light activates.

Sorry for the noob question but is a relay kinda like a switch? If so, how come the one that you've linked Titan has 4 legs/connections?

TiTAN showed you a link to a solid state relay. It is a cross between a relay and a transistor. Works like a relay (one circuit that flows the triggering current, second circuit, the switched circuit, that carries your load'd current), but is built more like a transistor - out of silicon. Normal relays have a coil that your activation power runs through. Coil makes electromagnet move the switch. The switch carries the heavy current for your load. Solid state relay has no moving parts.

Hmm I see. If that's the case, why didn't Apexi just use the white wire (the one that is supposed to be connected to the relay) just fire a +ve current when the RPM is reached, and simply having the shift light earthed on one end so when the +ve is activated, it just lights up?

Because the relay system is a bit "blurry" to me at the moment lol

It's because you could get some dildo hook up a 50W shift light and cook the output transistor in the RSM. The relay decouples the two devices, so only a little current flows through the RSM's output, and you can have an arbitrarily large current switched by the relay.

Any relay able to switch the current drawn by your shift light will do.

The fuse is there to protect the cable. Whatever the wire size you have in the path (including whatever little rat tail of wiring hangs directly out of the shift light) will have a maximum current that it can carry before it gets too hot and melts/burns. The fuse is supposed to be sufficiently lower rated than that so that the fuse will blow before you destroy the wire and set fire to the car.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • Thanks Duncan, that's the best info I've read. Furthermore after learning about the PCM programming side controlling the factory boost solenoid, the purpose of the solenoid is to "bleed" boost when pin 25 is earthed, thus allowing spring pressure in the wastegate actuator to overcome diaphragm boost pressure, thus closing or reducing the position of the wastegate flap creating more boost as the turbo is able to spin faster. It's pretty cool to see a designated Pill to do exactly this, would have liked to have seen it with a tiny filter over the end for those moments in vacuum.  The constant bleed pill has now been removed completely from the system and solenoid boost control has been restored once again.   Case closed 😂
    • The wideband reading is meaningless if it's not running. Why are you using shitty old sidefeeds on any engine, let alone a Neo? What manifold and fuel rail are you using to achieve that? Beyond that, can't help you with AEM stuff as I've never been their ECU/CAS combo.
    • Manual boost controllers (where a little of the boost was bled off) were quite common back in the day, because they were cheap and easy. Generally they had a manual adjustment screw rather than being fixed like yours. Down side is they always bleed boost, not just when you want them to so an electronic boost controller that uses a solenoid will have less lag.
    • Hello , im new here and i have A31 home build  RB25det neo stock eng / turbo  aem ems 2 blue connector  aem 3.5 map aem cas disk aem wideband connected to ecu  355 lph pump 550 nismo yellow injectors side feed aftermarket regulator  and won’t start with base aem tuner basic tune eventually flipped cas 180 degree so it triggers on correct stroke not in exhaust cycle  Now it won’t start Wideband reads 10 and 11 at lowest fuel setting  and will share calibrations soon for aem tuner i think something is wrong in aem tuner    please if you have any information, am very grateful         
    • Legend. I ended up finding the facebook account of the owner of the first car i sent but sadly he deactivated the account. I think you’re right in saying it’s some sort of well done custom job. Really appreciate your help anyways.
×
×
  • Create New...