November 9, 2005

Today was a day of more wiring. It seems like it takes forever to do, and that you don’t see much progress too. I just plodded on. I took a break from the fuel pump wiring and put the Reiff preheater bands around the cylinders on the engine. Around here, these will be a necessity for keeping the engine cozy in the sub zero temperatures.

Of course, I had to give them a go. They get pretty hot. Too hot to touch in fact. The cylinders suck up a lot of heat too. These will be more efficient when the cowling is on and there’s a blanket over it to keep it warm at night.

Next I finished the ANL current limiters as my order came from McMaster-Carr for the countersunk screws. I had to make some bus bar to connect everything together down here. The 60 amp one is for the main alternator, and the 40 amp one is for the aux alternator. I had a discussion with Bill at B & C about what to use for the aux alternator, because on the Z-12 AeroElectric scheme, it shows a fusible link. Bill said that the SD20 is really cabable of being a 40 amp alternator, and that it just doesn’t turn fast enough on the vacuum pad to ever make this. He said they use a 40 amp ANL with their STC’s for different aircraft. I guess it must be OK for me right?! You can see the lead here is the B lead to the main alternator.

Back to the fuel pump… I had to call Aerosance to figure out their wiring diagram for the fuel pump relay. I thought I’d figured it out, but I guess I couldn’t see why the fuel pump would go on when the switch was in the on position. It was apparently obvious though, as the relay contact for ‘on’ are normally closed, so all you need is power to come through the switch. I don’t know why I wasn’t seeing this. I guess I had a moment of stupidity hit me.

I continued on then, now it was all figured out. Here, I’ve made the connections to the pump. I couldn’t for the life of me find any info in the pump literature about which terminal was positive and which was negative, or even whether it matters. I’d long since removed the PVC cables and threw them in the bin. I took a gamble and wired it as you can see. When I got home, I checked Dan’s site, as I know he has one of these pumps… Yep, of course I had them the wrong way round! Tomorrow, I’ll be switching them then. What a pain! It’s not pleasant doing these things right now, as I picked up a couple of injuries playing soccer last Monday. I have a big graze on my knee which makes bending it in trousers a bit tricky, and a black toe which makes bending it in general tricky

I scored a goal though!

Time to start working my way along the switches to make sure they’re all done. Not much to show for pictures at this stage, as all the wires are starting to look the same! First switch was my Master. I needed to run the main alternator field wire from the Main bus to the switch. Did that. Then, the aux alternator, same thing. Did that. The next switch is E-Bus Feed, which is done anyway. Then the EFIS and Auto Pilot switches are both already done too. Now we get into the lights. First up is Nav. These weren’t done, so off I went running more wires. The tail light had been done sometime last year, but I’d not ran anything out to the wings yet. Now’s the time. It also needed power from the bus.

Here’s the rear Nav light working. The others will have to wait until the wings go on, which might not be very long….

Next switch along is the Strobes. They’re all done. Wires have been hanging out the sides of the plane for an eternity for those! Next up is Landing light and Taxi light. They needed running too. Did that. Then the map lights. I got the runs to the map lights done, but not the feed from the battery bus yet. I want to be able to turn these on without having the master on. Might be usefull. I also have those interior lights I can turn on too from the battery bus. Do I smell a chance of a dead battery coming on in my future? Did some dummy leave his lights on? Anyone got any jump leads?

Once the map lights have been run, the only things left are the Com 2 antenna in the left wing, the autopilot cable to the right wing, and the GPS antenna for the GX-60 through the firewall. For the first, I need to order some more RG400 from SteinAir, and the second, I’ve absolutely no idea how I’m going to route that thick cable through there. I think I’m going to have to drill another hole in the spar to pass through. Once that’s completed, I’m 100% with all my cabin wiring. Finito. Soon I can concentrate on getting ready to put the wings on. When they go on, I don’t want to be pulling them off and on too many times. I’d like to just maybe take them off once, tops. If I can get away with not pulling them off at all, I’ll be even happier!