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HELP! No RPM reading on the AFS 3500..??

A

ao.frog

Well Known Member
Hi.

To start with the GOOOOD news...: the engine started today!! What a great feeling to sit in the cockpit and feel the plane ALIVE...!!
It was just sooo ready to go up into the wild blue yonders!

Everything seems to work ok too, except that I had no RPM reading on the AFS 3500.
We've set it up for 4 pulses and we tried 2 pulses, but no RPM.

Setup: Superior IO-360, dual P-mags

The tach signal is taken off the right P-mag and hooked up to the main cable of the 3500, using the white/green wire only.

On the wiring diagram for the 3500, it's also shown a + and a - wire, but it looks to me that they are for a RPM transducer?
So far I've been thinking that the white/green wire is all that is needed...?

Any ideas anyone?

Thanks.





 
Alf, if you are taking the signal from the P-mag I think you should be using Pin 33 if I remember correctly. Its a bit late here now but look at the docs., p44 'electronic ignition'. I think you need to move a wire in the plug.

If you are still stuck tomorrow I will take a more detailed look. Steve.
 
voltage level?

I believe the PMAG can put out either 5 volt or 12 volt tach pulses. Determine what the AFS 3500 is looking for, and then make sure the PMAG is setup properly. If you have to change it, run the PMAG utility on a notebook and hook it up to the PMAGs one at a time and make the change. Sorry, it has been awhile since I did it, and I am flying out a sunrise tomorrow morning.

Good luck.
 
If there's a ground lead coming out of the AFS-3500 for the RPM sensor, make sure it's a good connection.
 
Hook up with Rob Hickman the owner and brains at AFS, his head IS the 3500, I'll bet he will answer this post before you even get to call.
 
I have the 3500 and your right, they are for the RPM transducer tha is installed in the standard magneto. I would still check with AFS via email or their forum...lot's cheaper than a call from your home base.
 
Solved! I think...

Thanks for all the advices guys!

I checked our wiring today, and we hadn't moved the tach wire to pin 33. (shame on us...)

I managed to get the pin out of it's hole and into #33, so hopefully that'll do the trick.

In the south eastern Norway, rain has been pouring down all day, so I haven't had a chance to test it just yet.
The forecast is good for tomorrow, so hopefully we can check it then.
 
Still no RPM....

Hi again.

The white/green wire is now conneted to pin 33, but there is STILL no RPM indication on the 3500...

In one of the posts above, there's the following suggestion:

I believe the PMAG can put out either 5 volt or 12 volt tach pulses. Determine what the AFS 3500 is looking for, and then make sure the PMAG is setup properly. If you have to change it, run the PMAG utility on a notebook and hook it up to the PMAGs one at a time and make the change.

In the 3500 manual there's the same advice: to verify that the P-mags are in 12V mode.

My question is:
HOW do I do this??
The above post says to: run the PMAG utility on a notebook and hook it up to the PMAGs one at a time and make the change.

Can anyone please explain what " a notebook" is?
And how and with what do I "run the PMAG utility" and where is that hooked up to the P-mags?

Do I need some kind of tools, a laptop or something??

Thanks....
 
Notebook

I would assume he meant a notebook computer. I am not fimiliar with Pmags but from that response they must have a software utility to program the pmags.
 
one more thought

When I used the PMAG EICAD utility,about a year ago, I was using a USB serial port adapter and had to move the port number to one that EICAD recognized. If you have trouble, suggest emailing Tom at EMAG (look for his email address on the EMAG web site) because he wrote it. It did work.

Writing replies from beautiful West Yellowstone, Montana. Isn't wireless great when on the road, or skies in this case.
 
ao.frog said:
Hi again.

The white/green wire is now conneted to pin 33, but there is STILL no RPM indication on the 3500........

Thanks....
Click to expand...

Alf, at this stage my approach would be to drop Brad at e-mag [email protected] an email asking him 5 or 12v how they were set.

He will need the serial #s. If that is not the issue I have no idea. As others have said there is a lot you can do yourself with a computer but I suspect you dont like computers. For ignitions I have some sympathy.

Good luck, Steve.
 
They are at 12V...

Hi again.

I just got an answer from Bard at E magair. He confirmed that my P-mags are set up for 12V...
Kind of bad news really, because now I'm completely in the dark.

I've just sent a e-mail to Rob at AFS, hoping he'll have the magic sollution...

I'll let you know how it turns out...

In the meanwhile; here's a pic taken today during the ground run. Since I had no RPM, I shut down after 30 seconds... but it's a pic with a moving prop at least!

The airport was nice and sent over a fire truck just in case...

PS: I've changed my checklist now, so I'll raise the flaps prior to start up.

 
Last edited:
Problem solved....?

Hi again.

I received this e-mail from Travis Danner at AFS yesterday:

Alf
We have an RPM board that will wire in series of your TACH signal and allow you monitor the P-MAG TACH. I would like to get this in the mail tomorrow. Should we send it to the same address that the EFIS went to?
We have since updated our hardware but I believe your engine board was just before this. The P-MAG TACH signal does not generate enough power to get through our filter/step down.
Please let me know if this works. Thanks Alf.

So it looks like I need this board to get the RPM to work and it was nice of him to offer to ship it to me.
Has anyone else run into this and/or installed this board with P-mags? I've never heard of this before, nor is it mentioned in the manual under PRM sensor install for P-mags? Or have I missed something....?

I'll let you know how it turns out.
 
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