Greetings,
I am having issues trying to manually activate the actuators on a set of NPP mufflers.
From other threads, I found that grounding pins 1&2, then 12+ to pin 4, should close the valve, but nothing happens, on either actuator. I am able to move the valve a bit with a stick, but it doesn't rotate more than 3/4in. I had read in another forum about some actuators going bad if the car is tracked and they overheat, but the probability of both being bad seems low, but not impossible.
They supposedly came off a 2016 Z06 with 12k miles, have 2.75in pipes, and I got them for $150...which leads me to believe he lied when he said they worked. His son sold them to me and gave me that story.
Thank you for any advice you can provide.

Update: I pulled the actuator off an the valve moves freely, and when I bench tested the unit, I feel the motor attempt to move, slight jerk really, but that's all. I can spin the actuator back and forth with no binding or issues.
Really stumped now.

On a side note, while I have NPP on my 12 GS, these are going on my 1969 GTO because I love this option.

 

Aren't those PWM controlled? So you may not be able to just jumper some pins. There's a guy who posted recently that made his own wireless control. I'll see if I can find the thread.

 

Found it.

https://www.corvetteforum.com/forums...-retrofit.html
.

 

Wow, quite a bit involved in making those work. Guess I need to start picking up the components.
Thanks for the assistance, greatly appreciated.
Curious if the following would work as well. Anyone used this before?

https://tprace.com/products/gm-npp-valve-controller

 

Did you see their note at the bottom of the web page?

** PLEASE EMAIL FOR AVAILABILITY **
** THIS PRODUCT IS BEING REVISED AT THIS PRESENT TIME

 

Yup, and I emailed them.
Haven't heard back yet, but hoped someone might have used one with a previous revision.
Thanks again for the help.

 

Just heard back from them. They have been discontinued for about a year and there are no plans on building them again.
I will start buying the parts to build the other setup and let everyone know how it turns out.

 

Cool. That looks like a nice project. For just being a 2 position actuator it sure is complex. I think it's because the can bus that GM uses on the entire car.

 

Amazing that the pigtails are so expensive, $37 each + shipping from Summit Racing is the best I can find, but you can buy all the parts of the plug itself for <$10 from mouser.com.

 

Just dont forget the crimping tool if needed. Usually they are.

 

Thanks for looking out!

 

I know you've already found the solution I posted using an Arduino to control the actuators, but I'll take this opportunity to clear up some misconceptions about how these actuators work.

1. There is not a "calibration" that gets messed up running the actuators unattached to the muffler butterflies. The inside of the valves are very simple, but basically there is a motor with limits on it. You can break the valve so that the limits are mechanically not there anymore, but you can't do that by powering them or driving them open\closed off the mufflers.
2. The actuators must be driving with ground on pin 1, signal on pin 2 and 12v on pin 4. The signal on pin 2 needs to be pwm (pulse width modulated) 10v at 200hz with 80% duty cycle to close the valves and 20% duty cycle to open the valves. the waveform required by the actuator is pretty specific, 10v at 200hz.
3. A solution that some may find simpler to "control the actuators is to open them up and apply change the internal wiring to supply 12v and ground to the motors directly. This will work to open\close the valves if you are willing to remove the springs from the butterflies on the mufflers and then manage switching the polarity of the connections to the actuators with a relay or the like. If you choose this route, the actuators swing open to close in about 500ms so you could theoretically power them for about a half a second to open\close them, but overall this solution is more labor intensive and takes modification of OEM parts to pull it off.

For anyone who is looking for a solution to managing npp on a non npp car my solution at https://www.corvetteforum.com/forums...-retrofit.html