ACR’S on a 2005 FLH

[Rsw]

What is the best way to hook up auto compression releases on a 2005 Ultra? Can it be done thru the ECU? Was thinking about wiring in with the start wire but have heard that may not work. Thanks for any advice

[Ohio HD]

I don't think that ECM has the function to close a circuit to the ACR. Search the site, some have wired them to the starter button. The ACR's will just stay open until you let off the starter button. The later model ECM function from what I've read will pulse the ACR's open and closed with the motor spinning under the control of the starter. 

[Rsw]

Thank you I will try the start wire way. I didn't think the ecm was capable but wanted to check

[Don D]

Yes but you need a tts or similar flash tuner and must use an 07 download

[Eglider05]

Thank you I will try the start wire way.

This way has been working fine on my 05 for the last 6 years.

Rick

[Ohio HD]

I wouldn't change the MAP and have a retune to add ACR's, kind of expensive. If you're building a new motor or top end and will be tuning, then it's feasibley a cost effective solution.

[BVHOG]

Wiring to the starter circuit is not always the best option as the ecm needs to recognize the compression stroke in order to fire the plug. If your compression is not adequate you will have issues on startup. What I did on my 2002 bagger was to put a small switch just under the seat/tank area that I push till the bike cranks a bit. The moment you let off the switch the bike fires. I still feed the power from the starter circuit so there is no accidental release while operating. If I had the 05 ecm setup I would just do it the right way and wire it into the ecm. On a few bikes I have used the starter circuit for power and used the ecm ground pin mostly to avoid getting into some of the fuse blocks that are getting to be 10 years old or more and opening up a new can of worms when swapping pins around.

[FSG]

If your compression is not adequate you will have issues on startup.

easy to wire the ACRs to the starter and have them individually switchable so that if compression is low then the REAR ACR can be switched OFF

[speedzter]

I run a hybrid, one ACR via the start relay signal, and one via the horn switch .

[Rsw]

Compression shouldn't be an issue 124 set at 11.5-1. Thanks for all the ideas took the horn off maybe wire to that switch thru a relay