Thanks for post feature available again: viewtopic.php?f=7&t=17581

Repop ignition switches for big twins

Electrical issues
Forum rules
Please do not start new topics here, but here: New Panhead and Flathead topics
Post Reply
Mark44
Site sponsor
Site sponsor
Posts: 609
Joined: Mon Feb 23, 2009 5:24 am
Bikes: 1946 WL
1948-ish Pan
1991 FXLR
2000 FXD Dyna Superglide
2007 FXDB Street Bob
Location: Snohomish, WA
Has thanked: 13 times
Been thanked: 10 times

Repop ignition switches for big twins

#1

Post by Mark44 » Sun Nov 14, 2010 3:54 am

I've been having some electrical troubles and narrowed things down to an ignition switch that wasn't making good connections (~ 1sec delay when switching lights on, engine shuts off momentarily when lights are switched on). I did some of the usual things, such as cleaning the contacts and rotating the brass rod that makes electrical connections, but I was still having problems.

To take care of this problem, I bought a new switch from J&P, Heavy-Duty Electronic Ignition Switch for 1936-95 Big Twin (part no. 3000150). One difference between the OEM switch is that the one from J&P has 6 terminals instead of the 5 on the OEM switch.

After unfastening the + battery terminal, undoing the wires on the old switch, and removing it, I installed the new switch and put the wires on the same terminals I had taken them from, with no wires on terminal 3 or terminal 6. After this, I hooked up the + terminal on the battery, and tried it out.

I was very disappointed to see that turning the switch to the ignition-only position, the headlight came on, but not the taillight. Switching to the lights position caused the taillight to come on, but turned off the taillight.

My first thought was to send an email to J&P customer support, but when I started to describe why the new switch wasn't working right, I thought I could make a better case by figuring out exactly how the terminals are connected for each switch position. The attached drawing shows the standard 5-terminal switch in the top row, and the 6-terminal switch from J&P in the bottom row. The left column shows the terminals that are connected when each switch is in the ignition position, and the right column shows the terminals that are connected when each switch is in the lights position.
IgnitionSw.JPG
After looking at my drawings, it struck me that if I moved the wire from position 4 to position 6, the new switch would work the same as my original one. That's what I did, and it worked like a charm.

On the plus side, the old switch really was causing problems, and the new switch seems to be solving all of them.

On the negative side, the new switch took a lot longer to install than it should have, since the mounting holes weren't quite lined up with the holes in my dash, so a little work with the Dremel was called for, plus a few taps with a hammer and chisel. I've been following this site for long enough now to get the picture that many repop parts require some fiddling to make them fit right.

It also would have been nice if the maker of the switch designed it so as to keep the same relationship between the terminals as before. Failing that, a piece of paper saying that the terminals had been moved around would have been nice. I will contact J&P's customer support about this.

Anyway, some of you will likely be replacing your ignition switches at some point, so I hope what I found will help you out.

Mark
You do not have the required permissions to view the files attached to this post.



Panshovevo
Posts: 293
Joined: Sun Jul 25, 2010 5:18 pm
Bikes: '50 F model, '76FX/L, '96 96" FXDWG
Location: SE Florida
Has thanked: 8 times
Been thanked: 6 times
Contact:

Re: Repop ignition switches for big twins

#2

Post by Panshovevo » Sun Nov 14, 2010 5:33 am

I currently have three different aftermarket switches on hand, no idea of where two came from, but one is a V-Twin part. None are the same, none match the original wiring diagram in the Panhead manual.

Regards,
John

Mark44
Site sponsor
Site sponsor
Posts: 609
Joined: Mon Feb 23, 2009 5:24 am
Bikes: 1946 WL
1948-ish Pan
1991 FXLR
2000 FXD Dyna Superglide
2007 FXDB Street Bob
Location: Snohomish, WA
Has thanked: 13 times
Been thanked: 10 times

Re: Repop ignition switches for big twins

#3

Post by Mark44 » Sun Nov 14, 2010 6:34 am

I don't remember seeing any markings anywhere on the new switch. The one I replaced was made in Taiwan, so might have been from V-Twin.

TimmyV
Posts: 147
Joined: Sun Jul 19, 2009 9:27 pm
Bikes: 1961 FLH
2017 FLHTKL
Has thanked: 5 times
Been thanked: 6 times

Re: Repop ignition switches for big twins

#4

Post by TimmyV » Sun Nov 14, 2010 3:51 pm

You might also want to check that the "OIL/GEN" light enclosure is not rubbing on the wires hooked to terminal #6 in your diagram. I installed an H-D switch with 6 terminals & had to trim the enclosure a bit for clearance in that area. Just my .02

TimmyV

Panacea
Posts: 1864
Joined: Fri May 24, 2002 1:00 am
Bikes: 64FL 99FLHR 01FXSTD
Location: Mpls. MN.
Has thanked: 14 times
Been thanked: 57 times

Re: Repop ignition switches for big twins

#5

Post by Panacea » Mon Nov 15, 2010 12:18 am

Matt Olson Has just received a batch of new switch terminals he had made that are high quality, sounds like he has some testing to do before selling any though...Mike http://oldbikesinsd.blogspot.com/2010_1 ... chive.html" onclick="window.open(this.href);return false;

Post Reply

Return to “Electrical”