Heated Seat Wiring Question(s)

[rockitdoc]

I am wiring my plane and got to the fabrication of the switches for the seat heaters yesterday and then got a bit flummoxed.

The seats and heaters came from Classic Aero Designs. The wiring diagram is attached and the wiring for each part of the seat (back and bottom) is just two 14 AWG wires (red and black) with a quick connect plug. No harness came with the kit.

The flummoxed part is likely my inability to read this diagram completely. The battery, the one switch and the seats, I get (except the wire colors noted on the diagram don't match the seats, except for the ground (black)). But, what's the apparent 'other' switch in the upper right of the diagram?

Searches for ACC1009 came up short and I have a call into Classic Aero.

 

[KatanaPilot]

I am wiring my plane and got to the fabrication of the switches for the seat heaters yesterday and then got a bit flummoxed.

The seats and heaters came from Classic Aero Designs. The wiring diagram is attached and the wiring for each part of the seat (back and bottom) is just two 14 AWG wires (red and black) with a quick connect plug. No harness came with the kit.

The flummoxed part is likely my inability to read this diagram completely. The battery, the one switch and the seats, I get (except the wire colors noted on the diagram don't match the seats, except for the ground (black)). But, what's the apparent 'other' switch in the upper right of the diagram?

Searches for ACC1009 came up short and I have a call into Classic Aero.

You should have a wiring harness and a relay for each seat heater set.

I didn't trace the diagram completely but the seat heaters we installed from Classic (and others we have done) are wired a bit unusually. The relay is used to switch the heaters from series (on low) to parallel (on high).

We ditched the supplied harness and plugs and used aircraft grade wire plus Deutsch connectors to and from the relays and heaters. So I may have extra harnesses if Classic can't help you out.

 

[terrye]

The "switch" at the upper right is a Bosch 5 pin relay. It took me a long time to figure out the schematic with help from Luke at Classic Aero. The switch in the lower left is a nice R13-112 rocker switch with an internal green (Low) and red (High) LED. To make the LED work, the BLACK wire (not shown on the schematic) at the bottom of the switch connector must be grounded. The way the seat heater works is that in Low position the cushion and backrest resistors are connected in series (I think) and in the High position are connected in parallel. This is done by the Bosch relay. Pretty clever, but hard to understand at first.

You should ask Classic Aero for the harnesses, this includes the switch and relay. However, after lots of head scratching, I decided to make my own wiring harness (existing harness uses automotive wire, lengths not suited to my airplane) using the switch (pre-wired, I'm using that wire) and relay only. In addition, I've decided to replace the harness connectors with Mate-N-Lok connectors as I couldn't identify the connectors used on the existing harness.

 

[rocketman1988]

Yes

If you trace all of the wiring, that is what you will find. Series for low and parallel for high. I also did not like the generic harness and built a new one with tefzel wiring and Deutsch connectors.

 

[Desert Rat]

My harness is from Lemke but it's the same basic principle. When I got it, I just happily installed all of it, assuming that the relay needed to be there to handle the amperage.

It wasn't until I was wringing out the wiring that I discovered the switches they sent were more than adequate to handle the whole load and as others have said, the relay is there to switch between series and parallel which results in the high or low heat functions.

If I had understood this before I installed the harness I would have junked all that and just gone with a simple 2 wire parallel setup. Does anybody ever use low on heated seats? I know I don't.

 

[KatanaPilot]

If you trace all of the wiring, that is what you will find. Series for low and parallel for high. I also did not like the generic harness and built a new one with tefzel wiring and Deutsch connectors.

Bob, I think we are also related. Aero engineer, 121 pilot, having Evoke paint your plane.

You're the black sheep though for going with EFII on your RV-10

 

[rocketman1988]

Bob, I think we are also related. Aero engineer, 121 pilot, having Evoke paint your plane.

You're the black sheep though for going with EFII on your RV-10

That may be, but it isn't the first time I've been one of those!

As far as the EFII system goes, it has been flawless for 270+ hours. Starts every time, EGT match within 10 degrees and when I use the lean find on my Garmin system, all cylinders go blue almost simultaneously...not opinions; just observations over the last two years.

 

[rockitdoc]

Thanks. Figured it out. Helped to have the Harness

As with many things airplane, it helps to not lose parts. Turns out my harness with switches from Aero Designs was lurking in my hangar in the original boxes I hadn't opened, yet. Duh.

It took the morning to re-fabricate my console panel where the switches reside, but got it done before lunch. No biggie.

Thanks, again.

 

[rockitdoc]

Console with Seat Heater Switches in Place

Mounting the relays, running wires is all that's left of this part of the project. Really glad I found the switches. They have a low and a high setting as well as an off. Way better than the toggles I was going to use.