jimx Posted January 20, 2012 Share Posted January 20, 2012 Hi guys......just joined and looking for a bit of advice.... ...I'm not new to playing, but pretty new when it comes to tinkering with my guitars.. ..I thought I would attempt what I thought would be a fairly straight forward pup swap out by replacing the stock pups on my Epi LP with a set of Wilkinson hot Zebra pups.....they are the four wire version and i joined and taped back the red & white wires and connected the black (ground) and yellow (hot) wires of both pups as instructed....seemed quite easy, even for me...then when I plugged in I only had sound through the neck pup, nothing through the bridge or middle positions ??....I checked all my connections and continuity seemed ok...thinking the bridge pup might be dead I then wired it through the neck pot and it worked ok...I then re-wired the pups back to the proper pots and still had the same result ,,only the neck pup was active....I even replaced the bridge volume pot with the same result... ..do any of you tech-minded guys out there have any thought as to what I could have done wrong, or any advice as to how I can trace the problem before taking the guitar to a Tech .....I'm pulling out what little hair I have left here... ..as I said, I am new to all this and I don't mind taking a bit of ribbing if it means getting this sorted...... cheers guys !!!!!!! Link to comment Share on other sites More sharing options...
RaSTuS Posted January 20, 2012 Share Posted January 20, 2012 Hi Jim and welcome to the forums, great bunch around here, I hope you like it. If it's not the pot, and both pups only seem to work in the bridge position, I would suspect that the 3-way switch could be at fault, or the wiring to it. 1/ Did you only change the wiring as far as the pots ??? 2/ Do both pots still have the wire going from the centre lug to the switch ??? 3/ Is the bridge pot grounded (not only to the pickup, but to the rest of the grounding) ??? Link to comment Share on other sites More sharing options...
jimx Posted January 20, 2012 Author Share Posted January 20, 2012 Hi Rastus...thanks for the response and the welcome !!! I didn't touch the switch wiring at all...it was just a straight forward old pups out then new pups wired in to the same positions, although i did after realising I had a problem check the continuity from switch to pots which was ok and all the pots have ground continuity to each other.....just to be a bit clearer the guitar only plays in the neck position ..no bridge or middle....I only wired the bridge pup through the neck pot at one stage to make sure that the bridge pup was actually working ok, which it did ..????? Link to comment Share on other sites More sharing options...
RaSTuS Posted January 20, 2012 Share Posted January 20, 2012 That's extremely puzzling, any chance of getting a pic of the control cavity and posting it. Link to comment Share on other sites More sharing options...
jimx Posted January 20, 2012 Author Share Posted January 20, 2012 ...I'll see if I can get a photo on....though I'm not to clever when it comes to the techno stuff !!! Link to comment Share on other sites More sharing options...
RaSTuS Posted January 20, 2012 Share Posted January 20, 2012 ...I'll see if I can get a photo on....though I'm not to clever when it comes to the techno stuff !!! Easiest way to post just one or two pics is to use the "Click To Attach Files" button when you are in the posting editor, it's a large dark blue button just under the text area. Link to comment Share on other sites More sharing options...
jimx Posted January 20, 2012 Author Share Posted January 20, 2012 ...I've made an attempt at adding a couple of photo's....I'm not sure if they will show much apart from some crappy soldering !!!! Link to comment Share on other sites More sharing options...
RaSTuS Posted January 21, 2012 Share Posted January 21, 2012 ...I've made an attempt at adding a couple of photo's....I'm not sure if they will show much apart from some crappy soldering !!!! To be honest, I can't tell from those pics, my eyes aren't brilliant and they're a touch on the small side. Perhaps a good wiring diagram might help you, this is from the Seymour Duncan website, the colour codes might be slightly different, just ignore that and imagine your colours in their place. Important thing is to follow the wires, and see if yours hook up in the same manner. SD Wiring Diagram Link to comment Share on other sites More sharing options...
jimx Posted January 21, 2012 Author Share Posted January 21, 2012 I thought the pics might be a bit too small to show much.....I have a copy of the SD diagram, I have also got a vintage LP scematic from a guy on another forum to try out as I reckon me best bet is probably to rewire the whole lot from scratch....thanks for your help Rastus..I guess I'll probably hang around this place for a while now that I have found it.... Link to comment Share on other sites More sharing options...
RaSTuS Posted January 21, 2012 Share Posted January 21, 2012 I thought the pics might be a bit too small to show much.....I have a copy of the SD diagram, I have also got a vintage LP scematic from a guy on another forum to try out as I reckon me best bet is probably to rewire the whole lot from scratch....thanks for your help Rastus..I guess I'll probably hang around this place for a while now that I have found it.... Just a tip, when soldering to pots, always have them set to zero, that way if too much heat is introduced the dead spot will be at zero anyway, especially when wiring grounds to the back of them. Good luck with it mate, I hope it works out for you, please let us know and don't hesitate to ask if any guidance is needed along the way. Link to comment Share on other sites More sharing options...
RaSTuS Posted January 21, 2012 Share Posted January 21, 2012 BTW: If you're going to rewire it you're better off getting a Switchcraft switch and jack, they're rock solid, one of the biggest failings of Epis wiring is these components reliability. Link to comment Share on other sites More sharing options...
jimx Posted January 21, 2012 Author Share Posted January 21, 2012 thanks for the tips Rastus.......see you around Link to comment Share on other sites More sharing options...
Gordy01 Posted January 21, 2012 Share Posted January 21, 2012 If you did a direct replacement, wiring the pickups exactly as the old ones came out, and making certain the red/white connections are solid, then it pretty much has to be in the connections. I am assuming the old pickups worked OK. The pics you posted were too small for me to see, so I am assuming everything I say. In the process did you remove any other ground wires? Like RasTus says, those stock switches are prone to failure. Could be that. Maybe you pulled a wire loose on the switch while working. Or it could be you baked the pot, but that is doubtful. Link to comment Share on other sites More sharing options...
brianh Posted January 21, 2012 Share Posted January 21, 2012 BTW: If you're going to rewire it you're better off getting a Switchcraft switch and jack, they're rock solid, one of the biggest failings of Epis wiring is these components reliability. Well, Switchcraft is better than most. but I've had a bad one - bent contacts (look for that by the way). Bottom line, check your pickups and all your pots and switches with a multimeter BEFORE installing. Link to comment Share on other sites More sharing options...
RaSTuS Posted January 21, 2012 Share Posted January 21, 2012 Well, Switchcraft is better than most. but I've had a bad one - bent contacts (look for that by the way). Bottom line, check your pickups and all your pots and switches with a multimeter BEFORE installing. I vaguely remember you mentioning that once Brian, but considering how many of us have used them over the years, one failure up against hundreds of successes seems an extremely good track record for their product. Link to comment Share on other sites More sharing options...
Pete B Posted January 21, 2012 Share Posted January 21, 2012 Seems rhat somehow the bridge pickup is grounding and it's grounding the neck in the middle position or at least your would be able the hear the neck in the middle position. Link to comment Share on other sites More sharing options...
mrw1960 Posted January 21, 2012 Share Posted January 21, 2012 Bottom line, check your pickups and all your pots and switches with a multimeter BEFORE installing. +1 Link to comment Share on other sites More sharing options...
brianh Posted January 21, 2012 Share Posted January 21, 2012 I vaguely remember you mentioning that once Brian, but considering how many of us have used them over the years, one failure up against hundreds of successes seems an extremely good track record for their product. Alls I'm saying is that even the best components can be defective out of the box. In my case it was that the contacts were bent possibly by me but more likely by the distributor (Allparts) or during shipping. Nothing against Switchcraft at all just that it cost me half a day looking for other problems when the answer was staring me right in the face. My mistake was that I thought a Switchcraft part couldn't possibly be defective because they're supposed to be infallible, like the Pope. Link to comment Share on other sites More sharing options...
Lefty Bill Posted January 21, 2012 Share Posted January 21, 2012 Hi, Jimx and welcome to the forum. My recommendation is to unsolder/lift the Bridge hot/A+ signal wire (yellow) from the Bridge pot terminal (and tape the end). With that removed, the Neck p-up should play in "both" the Neck and Center switch positions.. if it doesn't, the trouble is likely more easily found with the Bridge p-up being isolated/not interfering. You didn't mention what you were using for checking continuity in the initial checks. If you have a meter, check the Bridge pot terminal (where the yellow A+ lead was removed from) to a ground point. If the reading is near zero ohms, rotate the Bridge pot. If the reading is still near zero or a low reading, then there is a ground path right there at that terminal (make sure no part of the terminal is touching the conductive black coating covering the inside of the controls cavity). A ground path at the Bridge pot terminal would cause the conditions you stated.. no output with the selector switch in either the Center or Bridge positions. If the reading at the terminal changes with rotation of the Bridge pot, then the trouble may be in the 4-wire lead bundle for the Bridge p-up. I don't know what the white tape is covering near the ends of the p-up leads (I understand that you said you joined and taped back the red and white leads).. but it may be concealing the problem. If there is a braided shield over the p-up leads, this may be where the trouble is.. pull the white tape off and remove a short length of the black jacket material, then very closely inspect the insulation on each wire in the bundle (especially the yellow wire) to see if the insulation got too hot during soldering.. if the yellow makes contact with the ground lead (braided shield or black wire), the signal will be killed from the bridge p-up, and this may have corrected itself (intermittent contact) as the wires were moved around when you connected the Bridge p-up to the Neck pot. If there is an intermittent connection/short circuit between the Bridge yellow lead and the ground in the bundle, that should be visible with a magnifier, if needed.. then you can slip a short length of shrink tubing (or equivalent insulation) over the yellow lead to insure it doesn't make contact there again. So, with the Bridge p-up yellow lead still disconnected from the Bridge pot (assuming that you are using a meter), check the resistance from the yellow lead to ground.. it should not be near zero. The reading should reflect the resistance of the Bridge p-up coils.. so the reading should be over 5k ohms (maybe up to 12k or more). If the reading is near zero when checked from the Bridge p-up yellow lead to ground, there is still a fault in the 4-wire bundle.. and more black jacket may need to be removed to separate the yellow lead from the bundle ground. FWIW.. The operation of the typical open-frame selector switch is that.. in the Center position, both p-ups are connected/on (yeah, you knew that). When the switch is moved to the Neck position (since the Neck p-up is already connected/on,) the switch opens/disconnects the Bridge p-up. Likewise, when the switch is moved to the Bridge position, the switch opens/disconnects the Neck p-up. Regards, Bill Hi guys......just joined and looking for a bit of advice.... ...I'm not new to playing, but pretty new when it comes to tinkering with my guitars.. ..I thought I would attempt what I thought would be a fairly straight forward pup swap out by replacing the stock pups on my Epi LP with a set of Wilkinson hot Zebra pups.....they are the four wire version and i joined and taped back the red & white wires and connected the black (ground) and yellow (hot) wires of both pups as instructed....seemed quite easy, even for me...then when I plugged in I only had sound through the neck pup, nothing through the bridge or middle positions ??....I checked all my connections and continuity seemed ok...thinking the bridge pup might be dead I then wired it through the neck pot and it worked ok...I then re-wired the pups back to the proper pots and still had the same result ,,only the neck pup was active....I even replaced the bridge volume pot with the same result... ..do any of you tech-minded guys out there have any thought as to what I could have done wrong, or any advice as to how I can trace the problem before taking the guitar to a Tech .....I'm pulling out what little hair I have left here... ..as I said, I am new to all this and I don't mind taking a bit of ribbing if it means getting this sorted...... cheers guys !!!!!!! Link to comment Share on other sites More sharing options...
jimx Posted January 21, 2012 Author Share Posted January 21, 2012 .....thanks guys, a lot of good advice given and received !!!..... ...went to the local guitar shop today and picked up 4 new pots and 3-way switch and was thinking of re-wiring the pups on a cardboard template first before fitting to the guitar (if all tests out well)......although I will try out Lefty Bill's suggestions first, might have something there?..it would save me a bit of time and if there is a problem in the bundle it would just carry over to the new set-up, so best get that checked first... ...I'll let you know how I get on....thanks again for all the tips !!!! Link to comment Share on other sites More sharing options...
jimx Posted February 7, 2012 Author Share Posted February 7, 2012 ...hey Guy's, just back with an update.... ...not quite sure what went wrong originally...but I think Lefty Bill may have been right about a problem in the bridge pup bundle ?....as I stripped back both sets of pup wires and rewired the whole guitar again (50's wiring) with braided wire, stuck in new caps, CTS pots, switchcraft switch and jack...and eureka !!, back in business.....may have cost me an extra few bucks but it has definitely been a worthwhile exercise, I'm not sure whether it's the new pup's, the re-wiring or a combination of both, but the guitar is sounding great!!......haven't touched the Strat or Tele for at least a week now !! ...thanks for all the advice guys!! Link to comment Share on other sites More sharing options...
RaSTuS Posted February 7, 2012 Share Posted February 7, 2012 Glad it worked out for you mate, good stuff. Link to comment Share on other sites More sharing options...
Lefty Bill Posted February 9, 2012 Share Posted February 9, 2012 Good on ya, JIMX.. glad to hear you got your guitar issues resolved. Patience and persistence will generally always result in success. Wiring products just ain't what they used to be.. insulation keeps getting thinner and softer, and won't tolerate much heat from a soldering iron. Your pics didn't show if those pickup leads had braided ground shields covering the small signal wires, but overheating any of the conductors in a multi-wire cable can cause shorted wires nearby (often inside the jacket covering them).. sometimes obvious ones, other times they may be intermittent, depending upon how the cable is moved for installation. Braided shields can require quite a bit of heat particularly when attaching them to Vol/Tone pot covers and switch ground terminals, so a good practice is to clip on an alligator clip between the solder joint and the cable, to act as a heatsink.. this will absorb some of the stray heat which can travel fairly quickly along copper conductors. Additionally, all of the strands of a braided ground shield don't need to be included in the solder connection, so some of them can be trimmed off so the connection doesn't need as much heat to reach the solder re-flow temperature (beware of stray strands and the very fine scraps when trimming). Trimming ground shields applies only to signal ground shields, not to any other type of conductors in other types of electrical circuits, just to be clear about that. A popular product a few decades was a clip-on heatsink tool/soldering accessory which had a couple of thick plates on the tips, which would absorb stray heat more effectively than alligator clips. A good practice is to tin the bare/stripped wire end and tin the terminal where it will be connected to, separately.. then join the two with a final, but brief application of heat to make a secure connection. Bill ...hey Guy's, just back with an update.... ...not quite sure what went wrong originally...but I think Lefty Bill may have been right about a problem in the bridge pup bundle ?....as I stripped back both sets of pup wires and rewired the whole guitar again (50's wiring) with braided wire, stuck in new caps, CTS pots, switchcraft switch and jack...and eureka !!, back in business.....may have cost me an extra few bucks but it has definitely been a worthwhile exercise, I'm not sure whether it's the new pup's, the re-wiring or a combination of both, but the guitar is sounding great!!......haven't touched the Strat or Tele for at least a week now !! ...thanks for all the advice guys!! Link to comment Share on other sites More sharing options...
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