Getting ready to rewire...suggestions?

[mlrtyme]

Just purchased the 10205 Painless kit for my newly acquired 84 Jimmy and plan to rewire so I can toss the hacked up factory harness in the garbage. I'm familiar with rewiring vehicles so the obvious items (good grounds, measure 3 times before cutting once, lightly clean the connections on the printed circuit board, don't put the tach lead onto the gas gauge power feed post ) are a given. However, what K5-specific items should I look for?

Here's what I have so far:
- Tailgate: Make sure that the power window safety switch is disassembled and cleaned. Check the power cables for corrosion and ground and repair where appropriate (with proper solder and heat shrink tubing)
- Doors: Plan to remove each power window/lock switch and clean terminals
- Dash: clean terminals for tailgate window switch
- Chassis: Check fuel sending unit for proper ohm operation and good ground

Anything that anyone else has run into that I should be aware of before diving in this 3 day weekend to start?

Thanks in advance...

MLRTYME

 

[ktmoutfront]

To the gate and door windows, go one size up on the wire.

 

[dyeager535]

I'd say to simply bypass the switch in the tailgate. If you are that far into it, might as well remove it. Not a good thing when (not if) that fails.

I can't think of much else that is K5 specific...dome light wiring is different because of the K5, but same concept as all the other C/K's of that vintage.

 

[MrSchaeferPants]

Only thing I could think of is to check out your wire and harness securing straps, the plastic clips and such that hold stuff in place. Might need a bunch if those don't come in the kit.

I'd personally switch headlights and windows/tailgate to a relay system while you're in there.

 

[dyeager535]

I had wondered about relays for the rear window. Since you can't shorten the wiring run, is there much of an advantage to running it with relays?

I assume the power for the motor runs right through the switch, which may be a point of voltage "loss", but I've not noticed that the tailgate key works any better, and I expect that it might since it's probably more robust than the dash switch.

Running relays would allow larger wiring to be run to the motor, but without going to monstrous cable (battery size), can you go up one or two sizes of wire, or is what is already used the largest common size already?

Voltage is "reversed" to the motor for up vs down, so what would the wiring diagram look like for the motor/relays?

 

[Highpsi]

I had wondered about relays for the rear window. Since you can't shorten the wiring run, is there much of an advantage to running it with relays?

I am by no means an electrical expert, but I have rewired my truck and built a custom harness and integrated some relays for headlights. I think you've got the idea already and understand the purpose for the relay. It really isolates the circuit from high vs. low current flow. More specifically, the switch. So in the end, by utilizing a relay you'll see better reliability out of your switch, and as you stated, no voltage drop across the switch which obviously leads to more reliable current flow to the motor.

Running relays would allow larger wiring to be run to the motor, but without going to monstrous cable (battery size), can you go up one or two sizes of wire, or is what is already used the largest common size already?

You can go (down = larger) in the gauge of the wire to as far as you want to! In fact, the bigger the better. However, this leads to problems with packaging and size requirements for the application, plus potential overkill for the load demand on the circuit. If the current wire is of say 16 awg, going to a 12 or so would be a cinch. Cost is a limiting factor here as well obviously.


Many of the circuits I rewired in my K10 I put larger gauge wire in them. My battery cables are enormous! (Guess I had to do something with all those old cables laying around from my marine technician days!) Some of it is overkill, yes. But that also leaves room for growth later if you plan to tax a circuit more than you wire for it right now.

Hope this helps a little.

 

[dyeager535]

The tailgate wiring may be 10 gauge already...? Which is kind of what lead me to wondering how much "better" you can get without going to the next commonly/affordably priced wire.

I'm not thinking it out very far, but it would seem that having to control a motor by reversing the voltage would take a fair bit of wiring (how many relays?), and trying to hook multiple runs of thick wire together would be pretty difficult.

I can certainly see the advantage, just not seeing a practical way to do it.

 

[Highpsi]

I completely agree with what you're saying here dyeager535.

One idea the OP might consider is going with a heavier duty switch then what comes stock. There's some pretty cool looking ones out there too that I found digging around. I don't know what the amp rating is on the stock switch but it is probably pretty low.

I really like Waytek for electrical supplies, but they make you buy in bulk most of the time so unless you've got a big project they're a bust.

 

[sweetk30]

i would run extra ground for all grounds that went to body . these days rust / corrosion / old age can make getting a good ground kind of hard at times. so a deticated ground added to each cirkit would help a lot. all the newer cars are doing this on most everything for multi reasons.

and as said relay mod for lights / window motors . and 0 or 2 ga wire from batt to alt pos+ stud over tiny wire stock.

lots of good star washers for grounds to body . heat shring tube with glue in them to keep crap out if you want best option.

 

[ryoken]

Getting ready to rewire... suggestions?

 

[dyeager535]

and as said relay mod for lights / window motors . and 0 or 2 ga wire from batt to alt pos+ stud over tiny wire stock.

How are the windows run stock? Just the switch itself? Don't have time to search unfortunately, I assume there is a diagram already done up showing how to install relays.

I also have to assume the windows operate the same in the doors as the rear (motor reversing rotation), which would mean relay wiring should be the same for both applications.

 

[mlrtyme]

I will check the shop manual

...to see which way they have current flowing for those switches, if possible. It came with over 100 pages of different wiring diagrams.

I recognize that this will be a bit more involved than the old Camaros and Chevelles that I have experience with, but I'm still looking forward to it. If I weren't one of those nutty Mormons, that 'cooler' might be right up the alley for most wiring projects I have undertaken....LOL!

Thanks for the suggestions on the tailgate switch override. I like the safety of having a switch there, but I'm still worried about what will happen 'when' the switch dies (in the most unopportune time, I'm sure!). I need to disassemble the tailgate keyed switch anyway (as the previous owner said it did not work) so I'll be in the tailgate anyway! Figure tackle that now.

I can see the benefit of a relay controlling the rear motor from the switch (to keep current load flat and low). I'll have to see what I can get from the local car audio shop or Pep Boys. Any suggestions on how much juice I should be setting up for from relay to motor?

As for grounds, I agree...can't have too many of them! The painless box came today and the new cruise/wiper/turn-signal level and switch come tomorrow so I can dig in this weekend. Wish me luck!

...and keep those suggestions coming. Very appreciated.