Electrical Circuitry Clean Up - Circuit/Junction Box

Bill - I've used that '96 EVTM extensively, and even then bit on the PDB is hard to use.  It is spread over several pages and I like to see it on one page.  Which is part of why I draw my own up.

Scott - Happy to clutter.  

Gary put up all those pictures just for me! I'm so special....LOL!

Hey, you guys ever use solder sleeves?

I've not used solder sleeves, but have wondered about them.  The low temp might reduce the tendency for the solder and rosin to wick up the wire strands and cause hard spots.

But I wonder about the ability for the solder that's in there to wick on the less-than-new wires we encounter in these trucks.  Is it rosin impregnated?  Do you need to coat the wires with rosin?

There were some instances where I used those on corporate type aircraft.

IIRC, it was changing incandescent Nav lights in the wings over to LEDs. They were in the kit sent by the manufacturer.

Stuck the wires in and hit it with a heat gun.

Usually we used these, this shows how they work. Very strong crimp. You can find some knock offs on amazon and ebay, they are around $200-300.

https://www.nature.com/articles/s41598-021-97498-8

I use these a lot. They work great, with a few caveats:

1. There are two kinds, the melting point is a giveaway. Most (I got https://www.amazon.com/gp/product/B07Z8SD8PB) melt around 110C which is perfect any common heat gun. I've come across a few that melt much higher though, so pick your poison. Another variant requires a crimp-then-shrink. I do not recommend these. I've had problems with the brittle, pre-melt crimps making holes in the insulation.

2. Normal crimp-style butt splices are pretty much strip-and-crimp to a quick gas tight connection. You rarely need to sandpaper old wire strands even if you found corrosion up into the insulation. But these things absolutely do require clean wire. If it's not bright and shiny when you strip it, you need to cut back a bit more, or clean it up somehow.

3. Most of these are adhesive lined so they're watertight too and those are my preference.

Regardless, these things are life-savers, I have them in every toolbox. In a pinch you can terminate them with a lighter although be careful, the insulation melts much faster than normal heat shrink so keep it moving. I've done all kinds of field repairs with them.

Thanks.  I ordered the 200-piece set and will give them a try.

If you ordered that one I referenced above, that's the one I have, quick tip. Use your heat gun's highest setting, but also, shrink both sides FIRST, then come in and hit the center until you clearly see it give way. The solder is nice to have but there isn't a lot of it, it's not super strong. If you hit the whole connector at once, it can fall apart while you're holding it while it's still hot. Heating the sides first seems to glue it all together.

Ill be posting my aftermarket box this weekend.  I ordered it when I ordered replacement header gasket set after soaking one side in engine oil last weekend.

I bought a few OE blocks but none of them had the number of fuses/relays I needed.  The one I got is a chinese no name one that I am going to fix up a bit but it has modules where if I bought another box I could mix and match the number of relays/fuses but it is a 18-way box in that it has 15 relay/fuse modules and 3 threaded fuse points for Mini ANL fuses.

In total the box has 10 five pin relays and 15 ATC/ATO fuses.  I thought about buying another one of these boxes to swap some relay modules as I dont need 15 fuses but I could always use extra relays how ever.  But I got it cause I need the 30A-50A 5 pin relays for powering my accessories from my aftermarket EFI to my headlight relay conversion to my up coming AC compressor relay conversion to take the compressor clutch off the dealer AC switch as well as to allow my sniper to cut the power hungry york compressor off at wot.

That looks like a nice kit, I’m saving it for future pondering!

taskswap wrote

If you ordered that one I referenced above, that's the one I have, quick tip. Use your heat gun's highest setting, but also, shrink both sides FIRST, then come in and hit the center until you clearly see it give way. The solder is nice to have but there isn't a lot of it, it's not super strong. If you hit the whole connector at once, it can fall apart while you're holding it while it's still hot. Heating the sides first seems to glue it all together.

Thanks for the suggestion.  And I did get the same kit, only the 200-piece one.

John - Here are my thoughts of what connections you'll need for the PDB:

Headlights: You'll need four connections: 1 for the low beam trigger; 1 for the high beam trigger; one for the low beam output; one for the high beam output

Voltmeter: That relay will have two connections to it: 1 for the trigger; one for the output

Blower: There are two things that can be done if you want to do it to take the load off the switches and speed up the blower motor.  You can use a relay to supply power to the motor, and you can use a relay to supply the ground for the high speed setting.  To do that you'll need two connections per relay, so four connections if you want to do this.  I don't know how effective it is, but I think Scott did some tests so you might search for that.

Fuse Links: You could replace the several fuse links with fuses if you want, but I'm not sure it is worth it.  I did it on Big Blue and Scott did it on his truck, and I may do it on Dad's truck as well.  But, there's no huge advantage to it, so I don't know that you need to do it.

Ground: You will need ground, but the way I recommend is to bring your ground lead out and terminate it with a ring-tongue terminal.  Then put it under a ground connection that you probably already have.  That way you don't need a connector but can remove the box.

What other functions or relays are you thinking about?  Fog lights?  Backup lights?

Rusty_S85 wrote

Ill be posting my aftermarket box this weekend.  I ordered it when I ordered replacement header gasket set after soaking one side in engine oil last weekend.

Looking forward to seeing this, Rusty.

Gary, thank you for your input. Just need to decide which way to go on the connectors now.