Electronics Basics and Reference

x2

Relay wiring comes up on a regular basis around here.

 

Original Post Updated:
1. wire gauge errors noted in red until corrected (Thanks to Trap)
2. Warnings inserted to make it clear I'm only showing a generic circuit, not a specific situation which may require other design consideratins (e.g. selecting wire due to its location, heat, etc).

Thanks for the feedback...keep it coming

 

Bump...updates:

Wire gauge ampacity updated in wiring section and circuit design section.

 

That's more like it. Perfect. You can put the marshmallows away. You won't be needing them.

My tips:

Heat shrink crimps work great. I see you can buy them at several auto places. They look odd sort of semi transparent. The ones with the glue inside are superior. http://www.google.com/products?hl=e...esult_group&ct=title&resnum=3&ved=0CDMQrQQwAg
Crimp pliers. Go buy yourself a set of Channel Lock 909 ones and throw those useless ones you got away. ( or sell them to somebody that owns a Ford or a Dodge )
http://www.swps.com/909.html?utm_so...ngengine&utm_content=909&utm_campaign=froogle
Work as well as the T & B ones and are 1/10th of the cost.

Can't handle crimps? These work great too.

http://www.posi-lock.com/posilock.html

Use something on the bare copper wire to prevent corrosion. Penatrox or Noalox or something similar. Water and DC current don't mix. I wire can rot off in a few short hours if it gets wet. Think electrolysis. Dip you bare wire ends before you crimp.

Solder? If you can solder. It's best. but needs heat shrink over it. You can even put Penatrox on it before you shrink wrap.

Zap straps. Toss them, you need really good ones for a truck. I recommend the "Black T & B TyRaps" from a electrical wholesaler, nothing else. Or use those useless zap straps to hold your really good T & B ones in a bundle or give em to a Chevy owner. T & B Black never gets brittle. If you want it off you must cut it off period. You will not break them even if there thirty years old.

Don't scrimp on wire. It's cheap. I would not use anything smaller than 18 gauge unless you have to for some reason. I'd even avoid 18 gauge and use 16 instead. Unless you have to for some fitting reason don't bother. DC does not like traveling threw small wires very far.

 

Good comments, I'll update the post to incorporate some of these points. I completely agree with getting rid of the crappy crimpers...it's just that I rarely crimp stuff, and when I do, I borrow my friend's quality crimper.

 

bump...55W bulb example included

 

Soldering section updated w/ pics

 

A tip if you are not a expert at soldering. Get yourself a can of Rosin Flux. Coat the wires or dip them into the tin of rosin if you can. It's a cleaning and flowing agent that will make it's simple. You just heat up the wire till the rosin starts smoking like crazy then touch the solder to the wire. It's will instantly flow then. Use a cloth to wipe off the excess rosin when done. Careful of dripping rosin. Make sure if it drips it will not drip into a bad spot. Even if you have rosin core solder this extra step will make it simple and quick. That is what you want to do when soldering. You should be fast to limit the damage to the insulation the heat causes. The extra flux will get you soldering fast like a pro. Acid flux is for pipes, never use it on wire. It will damage the wire over time. It never stops reacting.

Keep your soldering iron tips clean and tight. Use a wet sponge to wipe the hot tips across then tin with a thin layer of new fresh solder.

Make sure you slide your heat shrink onto the wire before you solder. It's the obvious department but it's easy to forget.

 

Have one of these for work, they're great. This is what I have in my truck. I prefer to use the uninsulated die for crimping, much better hold on the wire. Just my 2 cents.

 

Nice right up... I suddenly feel like I should go back and add pictures to soldering...

 

I have those too. There the best wire strippers made. Yes the none insulated crimp works wonders but I still use the 909 ones using the non insulated crimp. You can get into really tight spots with the 909 cause the crimps are on the end and you don't have to drape the handle over the wires. They have advantages over the stripper ones. Plus they have extra long handles so like that crimp is never going to come off. The stripper crimps on that set work ok on a pinch. Those pliers are not actually made by Klien. There made by the Cooper Tool Group that includes brands like Channel Lock, Xcelite, Vice Grip, The Channel Lock branded ones are cheaper then the Klien and they are exactly the same damn wire strippers.

http://www.channellock.com/908-Wire-Strippers.aspx

Cuts long machine screws too.

 

Thanks for the comments/suggestions! I tweaked the fuse tap, soldering, and crimping sections as well as added a wire stripper pic.

 

i need to install a harness for a trailer (4 pin) can i use a wire tap/splice at the rear lights to accomplish this.
i am using 14 gauge cable and the tap/splice will be sealed from the elements. i'm going to check the bulbs on the trailer to determine wattage later on today, i'm assuming that there can't be too much variation in trailer bulbs tho.......
i have consulted with a couple of people at work that have solid electrical back rounds and they are giving me a thumbs up on this, BUT i would like a second opinion.
Thanks,

 

Yeah, any aftermarket wiring harness for a trailer simply taps into the tail lights. If the trailer has LEDs, there is practically no problems...but if the trailer has bulbs, you should just check the wattage of the bulbs. Your owners manual should tell you the total maximum trailer bulb wattage for safety.

Note: many "plug-and-play" options for wiring harnesses can be purchased from most reputable trailer manufacturers. I'd suggest looking into one of those before using wire taps.

 

thanks for the reply larry, but i think i will probably go with the tap/splice as the cheapest harness that i can find around my neck of the woods is $70 plus tax as opposed to $3 for the tap/splice connectors.
on another note if i go with LED's on the trailer, do i need some sort of relay for them to "blink" correctly?
btw my truck is exactly the same model as yours, with the exception of it being an '10.
cheers,

 

Good question about the blinker. If you were to replace the tail light blinkers with LEDs then you would need a blinker module or a new flasher relay. This is because the stock relay flasher requires the resistance from the bulbs to blink properly. If you replace them with LEDs, you change the resistance the blinker relay sees and it affects the blinker speed.

However, I'm not sure exactly how an LED trailer blinker would affect the system. If I had to make a best guess, I'd say that it would work just fine because you haven't changed the tail lights. The relay flasher will still see the appropriate resistance because you haven't changed the standard load...the trailer LEDs would simply be an additional load and probably wouldn't change the blinker speed. Note: I towed a Uhaul with LED lights and it worked great, but I don't know if there was some sort of blinker module on the trailer itself. I'd assume it would work fine, but I can't say for sure.

 

thanks again, i will update once i get into it, today i have to install the wiring on the truck, replace the wood on the trailer i bought last week and paint it.

 

Let me know how it goes. Side note: even if you use LEDs for the trailer and it affects your blinker speed...it may be cheaper to just deal with it. It shouldn't cause any permanent damage to the blinker relay, it'll just blink fast when you're towing the trailer.

 

would anyone know which wires to spice/tap on the tail lights?

 

Shouldn't be too hard to figure out. You could consult the manufacturer's repair manual (it's on this site somewhere if you use the search function), or pull off the tail light and see what wire(s) go to what bulbs. You should be able to tell what wire is power and which is ground by where it is connected on the socket. If not, a multimeter will help.