Positive wire getting hot when shooting.
 

I'm having a look at one of my younger buddy's non working guns, and need some help here from the higher ups before I start digging too deep. The gun is a G&G m4. It is possible there's water damage? The gun was used in the rain a bit on the last game of the season, and started having troubles firing. He took it home at the end of the day, dried it out, (I don't know how thoroughly) and it was working again. However, it shortly started having hot wire issues in the battery compartment. (Just the Positive wire)
I looked and can't see any damages in the wire, and the motor etc does not get warm. Anyone have any clues what might be the problem?

no such thing as water damage. Either it cycles or it doesn't. Water in the gun just shorts it so it would shoot all the time. But since it's a simple electric circuit, that's unlikely.

POS wire getting hot is from resistance, from the fuse, from the wiring, from extra inefficient connectors, from messed up shimming or motor height. If the motor is not getting hot and sounds fine, shimming and motor height is probably not an issue.

You can fire an AEG underwater if you really wanted to and electrically and mechanically it would work just fine until the action of pumping water slowed the piston so that the sector PMEs and destroys the piston. There's a number of videos on YT featuring exactly that.

POS wire can get warm on stock guns though, that's the nature of the shitty electrical system from factory.

Either he didn't notice or there's added resistance in the system somewhere. Read above.

Well what I think we'll do is re wire it completely. The guy wants it wired to the rear for a full sized stock anyway, so maybe getting rid of the crappy wiring will fix the problem.

My experience and my suggestion for using AEG under raining is, get a clear plastic bag to cover up body and battery compartment to minimize the electrical parts and wiring get wet and having short circuitry. That will prevent this kind of problems for sure.

If your AEG having warm or a bit hot wire, it should be normal. I believe mostly of the wire comes with original in each AEG, they all just enough to handle the currency being used. And when you keep on shooting in full auto, those wire will become warm and even hot, as long as it not burning hand would be fine. But if having burning smell, that is the worst, you should stop shooting and have it check and service. Based on the case you mentioned, seems like some area got wet and mold grew in wiring contact area, when shooting it with currency went through, could have short circuit effect and having it hot on this single wire. That's is my simple diagnostic.

Yup a warm positive wire is normal. It all depends on the motor and battery setup also.

Hot wires are not normal unless shitty is your normal.

Use a wattmeter to test the amp draw.

No one said hot was normal?

If you're not melting through the insulation, it's perfectly normal for thing 18ga wires to get so hot you can't touch them. Especially if you're running a lipo on a motor that draws a lot of current.

Conflict of interest here! ;) I can personally say I don't think it's normal. This isn't my gun, but none of my 12-ish aeg's have ever had a hot wire unless something was wrong....

Check the fuse if there is one. It could give you clues if something is really wrong or if this is normal.

I've had just about every CA and marui and old G&G get super hot in the wires when using large NiMH batteries and 7.4 lipo
Resistance causes heat, and those shitty chinese wires have a lot of it.

Fuse has been removed and bypassed.

IT'S IN MY HANDS NOW! MUAHAHAHAHA!

I'll see what's wrong with it. Will probably just replace all the wiring if it's not long enough or has damage since it's being rewired from front to back.

Awesome! Let the pros handle it. There you go people.

cause you know, the other guys with the pro tags and the one who can't get one but still builds awesome guns for people are all wrong.

I think it was the combination of mini tamiya, the standard front wired blade connectors for disassembly, and some random soldered joint (didn't look at how good or bad a job that was).

Rewired to the rear with high quality silicone wire, no joints just the one mini connector. In the picture I hadn't shrunk the shrinkwrap on the wires yet :P

http://i.imgur.com/l0CupWZl.jpg

That's a nice wiring job.

is that leaded solder?

Thanks!

No it's electronics/rosin core solder.

there's electric rosin core solder that contains lead, at least so says the big spool of it on my bench.

I have a spool of it too. Works so well, but so bad for you...

I hate non leaded solder lol.. shit don't stick.

I always use leaded solder as well... I've tried silver solder and it's too much work...

As for the health issues, leads vaporization temperature is 1750C... that's a pretty good soldering iron if you're worried about lead.... it's the rosin core that's creating the smoke so still suggest using a mask but there are no lead issues....

Well this is Bernzomatic Electronics lead free solder.

I've heard/seen that opinion a lot lately, and I use non-leaded solder and never have a problem with it adhering.

I find people that have problems with non-leaded solder are doing two things wrong;

- using a 20w instead of a 40w soldering iron (go big or go home); and
- not using flux to prepare surfaces for soldering.

It could be true, I haven't used nonleaded since I got my soldering station, but even using a 40w crappy iron I had issues with the non leaded not adhering properly.

I just gave up on it and bought the leaded stuff and have been using that without issue, only when I run into crappy wires will it not adhere, and that's usually because pretinned/coated wire sucks up solder much more efficiently I find. Uncoated wire seems to need a lot of flux, whereas the coated stuff needs none at all aside from the prefluxed solder.

Heh, I have a Mastercraft (CanTire) soldering station with 20w/40w settings. I've never touched the 20w setting.

Mines an 80W, I have no problem getting anything hot lol
I'm also using this ancient acidic flux that just works fantastic on everything

I deal with PTW motors now, so everything is silver solder. The end bell gets so damn hot most leaded solders actually melt and let go after as few as 6 shots O_O

I should probably get a better/more powerful iron...

Gun doctor tag isn't necessarily a sign of competence, its just a sign that an admin thinks you're good enough to swap parts. There are a lot of really good techs that don't have the tag (obviously).

As for soldering, I use 60/40 Pb/Sn solder. I've tried lead free stuff and its fine for basic soldering up to 16 AWG, but when you want to quickly cover the entire soldering surface of a deans connector, soldering the inside of a motor connector, soldering MOSFETs together, or soldering bigass batteries with 10 AWG wiring, you need something that melts more easily. I sometimes have to use a bigass 240W soldering iron on 10 AWG wiring, and unless I use lead solder I still have trouble doing a nice, clean job.

I haven't had any of those problems using silver solder and an 80W soldering iron