[LettersFromFlyoverCountry]

Because I'm cheap , this is what I'm using for the mag switch on my RV-7A. I have one mag and one Lightspeed. The Lightspeed, as you might have guessed, is wired to another toggle switch, which will keep this one company in the panel.

I have a GRT EIS 4000 engine monitor which displays RPM so I'm going to wire this switch, and its little Lightspeed sister to another toggle switch, which will -- if I understand it correctly -- allow me to choose whether the GRT is displaying the RPM via the mag or via the Lightspeed.

So far so good? Good.

Getting the input from the Lightspeed is easy. It has an output that can wire directly from it to the toggle switch.

The other terminal of that switch, of course, will be wired to the data coming from the mag (by way of the switch above). It will also have an in-line resistor as required by the GRT.

The GRT, as I understand it, taps into the P-lede for its data, so I need to run a wire from the P-lede at the toggle switch above, to the other terminal on the toggle switch.

The question: What's the best way to do that? Jam two wires into one spade connector (doesn't seem like a good idea?) . Splice a separate wire onto the P-lede conductor (a little problematic, isn't it, because I've already added a pigtail in the wire to run a wire from the shield to the terminal in the toggle switch above?)?

 

[Brantel]

 

[Kahuna]

Jam two wires into one spade connector (doesn't seem like a good idea?) [/QUOTE]

Why is that a bad idea? There is nothing wrong with putting 2(or more) wires into a single fast on. A proven reliable technique for decades. Servicability is reduced. Reliability, speed, low cost are all increased.

 

[RVbySDI]

tease tease tease

Oh Brantel, don't tease us with pictures without giving us details!

How about a part number for those pictures? I am sure you can tell us where we can get them and what they are called too.

 

[Brantel]

I agree with Mike. Nothing wrong with putting two wires in one connector if you have room.

But there are options.

Here is one more version to tease with, just get the aircraft grade one not this cheap automotive one:

These type of connectors are available all over the place. I am sure Stein or B&C can hook you up with the good ones.

 

[flyboy1963]

weird connectors.....

Steve,
I know you need to buy a new connector(s), but if you want to see some creative stuff, pull the wiring harness out of a car! They use a ton of oddball things like the double-spade #8 Male-female bipolar transmogrifier shown above! ....all to allow addition of an accessory in a fancier model, or dealer installed alarm etc etc. all based on the same harness.
A lot of cool weather-proof molex connectors etc. reside under the hood, among other places.....of course.....
the downside to scrounging is wire gauge, colour and crimp connectors that are single-use.

 

[Kahuna]

I managed to track down my wiring bible, The Aeroelectric connection.
From that manual.....
=====
You may be tempted to twist the wires but resist the urge. This will make the bundle of wires LARGER in diameter making it difficult to insert the wires into the terminal. It will also ENCOURAGE strands to leave the fold as it were and become bunched up down around the insulation.

Use a gentle rocking motion to tease the strands into the terminal or splice's wire grip. It won't take any force to get the wires properly seated. If it does require much force . . . you're probably trying to put too much wire into the terminal. When you're ready to crimp, all strands should be visible at the open end of the wire grip
=====
And then I managed to find it on the web for your viewing pleasure.

 

[Radomir]

You'll have a mismatch because they output different signals (in different multiples).. so when LSE is selected, you'll read 2x the actual RPM (ie 3,000RPM when you're really at 1,500RPM)... It's annoying and crappy solution. I originally did this and regretted ever drilling that hole for that switch in the panel. Didn't take long before sending $80 or so to Vans for the tach sender made most sense and most convenience. I'm all about being cheap, but there are times when spending a few bucks makes life much better

 

[bcondrey]

The newest versions of the GRT EIS units support multiple tach inputs. Contact them for what it will take to update yours.

Bob

 

[RVbySDI]

The newest versions of the GRT EIS units support multiple tach inputs. Contact them for what it will take to update yours.

Bob

The last time I talked with Sandy at GRT was winter/spring of 2010 prior to first flight. They can upgrade an existing EIS to accept two tach inputs. At that time she quoted me a price of $100. I did not send my unit in for the upgrade. Instead I purchased a prop tach that is now sitting on the dash of the instrument panel pointing out the windshield at the prop. I like it, it works great. Whenever I do a "mag" check on my slick mag/plasma III ignition setup I find myself watching the prop tach numbers rather than the EIS. And yes, I am very satisfied the readout is accurate. Both instruments are within 1 or 2 RPM's at every setting. Both work as advertised. This setup cost more than what is being discussed here but the prop tach provides much more functionality to the equation. In my opinion, buying it was well worth the cost.

 

[LettersFromFlyoverCountry]

I agree with Mike. Nothing wrong with putting two wires in one connector if you have room.

But there are options.

Here is one more version to tease with, just get the aircraft grade one not this cheap automotive one:

These type of connectors are available all over the place. I am sure Stein or B&C can hook you up with the good ones.

ah, of course. My connector kit that Stein sells has those included in in the larger AWG, but not for the 18 AWG. Sounds like it's time for a road trip to the exotic land of Farmington, MN.

 

[LettersFromFlyoverCountry]

And then I managed to find it on the web for your viewing pleasure.

Outstanding. I don't know why I was under the impression only a single wire should be in a connector. Thanks!

 

[LettersFromFlyoverCountry]

The newest versions of the GRT EIS units support multiple tach inputs. Contact them for what it will take to update yours.

Bob

I'm VERY late in the build process and pretty much out of money. I need to make it work on the present budget.

You know, like the OLD-time homebuilders did.

 

[LettersFromFlyoverCountry]

You'll have a mismatch because they output different signals (in different multiples).. so when LSE is selected, you'll read 2x the actual RPM (ie 3,000RPM when you're really at 1,500RPM)... It's annoying and crappy solution. I originally did this and regretted ever drilling that hole for that switch in the panel. Didn't take long before sending $80 or so to Vans for the tach sender made most sense and most convenience. I'm all about being cheap, but there are times when spending a few bucks makes life much better

Hmmmm. Yeah, I can see that now. So the Lightspeed issues a different pulse per revolution?

That takes care of that idea.

Guess I'll just run the output wire straight from the Lightspeed to the GRT, screw the toggle switch and listen with my ear during the mag check.