wiring question

[fatdaddypreacher]

am having trouble getting new guitar build to work, and it is the simplest set up imaginable. one single coil, one volume, one tone. when i fire it up it plays for a few seconds , then quits...like it's 'bleeding off'. have changed caps to no avail. i have 500k's in now...is it that i need 250's. wiring ain't my forte'. i have checked wiring with two different diagrams, and seems to be right. thanks.

 

[Barnaby]

Sounds an awful lot to me like a stray wire inside is causing a short of some type. If you have a meter, I'd suggest checking all of the connections carefully. If you're using braided wire, that stuff can get strands in annoying places. Could also be a problem with the pup.

I'm terrible at wiring, however...please wait for an expert!

 

[fatdaddypreacher]

called myself looking for all the obvious, can't seem to see it. have rewired a couple of times. it plays for 3 or 4 seconds then goes out. by a long shot, wiring is my weakest task. i think i'll start building acoustics. thanks for the input.

 

[Murkar]

Well I can tell you for sure that it isn't because you need 250's because My LP jr build has 500s in it with the same set up as you (one single coil, one volume, one tone) with no problems whatsoever. It changes the tone a bit, but that's all it should do. Its odd that if something was touching where it shouldn't that it would play at all for a few seconds.

I had to sand a coating off the back of some of my pots because there was a coating on them that prevented the backs from being soldered (what genius thought of that?) - I discovered that the fine metal dust killed two of four pots and I had a similar result as you. It might be something like that - maybe one of your components has damage of some kind...try switching just the pots maybe, or something else, and see if it goes away?

Somebody with more wiring knowledge than me will chime in though I'm sure and say "I know! It's this, do this, and it's fixed."

 

[fatdaddypreacher]

thanks murkar. with virtually no basic understanding of the theory behind the wiring, it's kind of hit and miss with me. i can do okay with following a diagram, but i'm lost as a goose with diagnostics. if i can find the write book, i'd like to learn, but it seems as though everything i see takes off from an assumption of basic experience. i have some new cts pots i'll have to put in, but wanted to work out the bugs with these. perhaps there is an issue with one of them, although they read on my meter like they're working. thanks for the help, though. i'll wait a couple of days and see what comes up on this thread or what i can find elsewhere.

 

[MRJ5]

Check your switch, plug and grounds. Those are the 3 things that are connected to everything and would cause an all or nothing. Try to hold the guitar in different positions as well. The vibration of the strings while playing could cause the circuit to open.

If I were a betting man I would say look at the switch first.

It is difficult to diagnose an intermittent problem with out a meter and guitar in hand.

Sure your cable is ok?

 

[fatdaddypreacher]

i have no switch, just 1 volume pot and one tone pot. i have come to understand that the rating on the pots will only change it's tone, not keep it from working...unless defective, of course. they both respond to my meter from 0 to somewhere short of 490 on each, and operate smoothely. my cable is okay, as i plugged it into another guitar and is---and has been---working okay. I have wiggled and jiggled and found nothing works. for some reason, occasionally it will come on initially when plugged in, but then after a few seconds, it goes dead. when working the volume, i can hear it amplify in the amp, but when i tap on the pole pieces, i get nothing. somewhere down the line, it appears the feed to the pup is being interrupted. i even resoldered my ground on my jack, but didn't make a difference. i'm gonna start over with my new cts pots and see what happens, but i like to use this as a learning experience by locating my problem before i gut it and start over, because it may work just fine after redoing, and i won't really know what my problem is. (besides not knowing what i'm doing)

thanks.

 

[Barnaby]

i'm gonna start over with my new cts pots and see what happens, but i like to use this as a learning experience by locating my problem before i gut it and start over, because it may work just fine after redoing, and i won't really know what my problem is. (besides not knowing what i'm doing)

thanks.

On my first build, I honestly couldn't figure out the issue and simply replaced the pots. Everything worked fine after that, so, whether it was my soldering or the pots themselves, who can say? Sometimes, life is just mysterious.

 

[TKOjams]

bad instrument cable maybe?

 

[Ole'Lefty]

I just hazard a guess here- it sounds like something is heating up and at a certain temp, it gives up. With only 3 components;pickup, pot,cap, if all of your fooling around (necessary) in the cavity I would have to start thinking about the pickup-and its essential construction offers a good "environment" for building heat. Caps do it too but it sounds like you have bench tested it. I do not know how to load it(cap) outside a harness, but that would be the best way to check a cap for heat build up and failure that cycles.

 

[scimitar]

I'm certainly no expert but for any problem like this which is hard to trace I would start with the minimum in the circuit and then build it up and then you can tell which component has the fault. Start by unsoldering the pickup and just taping the wires to the cable jack plug, if that works then you know its not a pickup problem. Next connect in the volume but not the tone and try again etc.

 

[fatdaddypreacher]

good info from both of you. thanks. while i am ready to change everthing out, i still want to know what the problem is and learn how to troubleshoot. thanks ever so much. if my little heater will warm up my shop i will attempt to isolate the problem. will let you know what i determine after some time in my laboratry.

and yes, lefty, it does in fact sound like something heating up and 'going away' to me also.

 

[fatdaddypreacher]

rewired with new cts pots. one must have been fried...will test it out later. now my volume doesn't work. have to use the volume on the amp. must have a connection wrong, but it's munchie time. chili!! and it's freezin' out. the thing actually sounds pretty good for a 5 lb cigar box. Hard as the dickens to play. uncomortable as all get out.

will work on the volume thing later this week.

 

[Hazboticus]

Glad you got it fixed!

I have found with electronics and guitars that it is always best to do a test of your components before you install them with a meter and gator clips, you can do a 'test' wiring solder free just using the clip wires and it will let you work it all out before committing to the solder.

 

[fatdaddypreacher]

good idea. sure would save a lot of hassle. i was reusing same pots i set up all my builds with. guess one of them seen a little too much heat.

thanks.

 

[bruce bennett]

First put a meter on the output jack,
see if you can get a steady reading.
if not.. then the problem is in the guitar.
if so. the the problem is in the cable/amp.

once you narrow it down you can start using that same meter to follow it back toward the pickup until you find a steady signal.

My first bet is a bad or overheated pot.. but that amp/cable thing needs to be ruled out first.

just read the bottom of the thread.. great that you got it fixed.

 

[fatdaddypreacher]

well thanks bruce. looks like your first bet is right. i'm sure when i get to testing them, one of my pots took a hike. i've been reusing these for set ups, as i didn't want to put them in a guitar because they were the first i've fooled with while learning to solder. i'll also wager they've had their fair of heat....if you know what i mean.

thanks for posting. if it wouldn't be for you guys, i never would have been able to have the fun i'm having. hat's off to you guys that have been doing it so long it's second nature to you.