System Relay Mod

[TooManyToys]

I'll throw another option. Rather then using two relays all the time, use a SPDT switch somewhere accessible instead of the two momentary off switches so if the primary relay fails you can switch over to the other if access to the relay is restricted. This way you are not using up the life of both relays at the same time and run the risk that if one fails the other is not far behind. The issue with this is you can still have engine shut down with a relay failure until you can again access to the SPDT switch.

A redundant mode is a great idea, but I just don't see people testing every day or week for that matter once they get complacent. Well, unless you're involved in aviation and have developed the habit.

[raistian77]

Very nice write up. A quality relay will have a very long life span, my '74 and '59 Beetles still have the original VW relays in them. My advice would be to carry a spare and you should not have any problems.

Electrical systems tend to be the single most neglected and misunderstood parts of any vehicle system. I love to see when members find ways to optimize old electrical systems.

[posplayr]

Baring any infant mortality issues, the primary failure mode for there Bosch type mechanical relays is going to be vibration induced. Mounting two relays side by side under the same "poor" mounting conditions is improving reliability but only marginally. They are both likely to fail in the same way in near the same time frame given the accumulated stress conditions. The electrical load is not going to stress them.

Now you could start rotating them, but the tank bad is the best place for the spare. A switch to short circuit the relay output would be convenient if you cant get to your relay easily; personally I just chose a piece a wire to plug into the ends of the relay plug for that.

Personally I would get the wiring correct and relay mounting correct (relay mounted with compliance on the battery box) and be done with it; no special proceedures required.

[koolaid_kid]

Just an update. I used bakalorz' parallel relay system on my GPz. I don't have the switches yet, but it works just dandy. And, again due to limited real estate, the relays and fuse box the items are all located in different parts of the bike (3 total. I did what I call a generic relay mod, and it currently powers my Accel coils. It is very simple, consisting of 2 relays and a fuse box. The fuse box gives me 6 distribution points with easy access to the fuses, so I can install a cigarette lighter, GPS receiver, grip warmers, and a cappacino machine.
No wires were cut, and a return to stock method is in place.
If anyone would like a writeup on this particular mod, LMK. Otherwise I'll just enjoy it and hope it keeps running.

[Burque73]

Missing Link

The link in the first post here is disabled. Does anyone still have the PDF that they can email to me?

[P09luis]

The link in the first post here is disabled. Does anyone still have the PDF that they can email to me?

I'm also looking for this link.

[bwringer]

You'd need a seance to contact George (koolaid_kid), but a few of the folks who replied, cowboyup3371 and posplayr, are still active and just might still have the PDF lying around.

[Grimly]

This is a pdf from member Matchless, dated 2008, about relay mods.

http://www.mediafire.com/file/35ct8r99tojncgd/Relay_modification_for_bike_v23_byMatchless-1.pdf/file

[Steve]

Don't know about others, but I am having trouble getting anything from that Mediafire site.

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[Grimly]

Don't know about others, but I am having trouble getting anything from that Mediafire site.

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It downloaded for me immediately on a browser I wasn't logged in with.

[Burque73]

It worked for me too. Thanks Grimly.

[Burque73]

Don't know about others, but I am having trouble getting anything from that Mediafire site.

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I attached that PDF in an email to you.

[ToaDady]

i can' get the link to work, someone email it to toadady@hotmail.com please

[bwringer]

I've placed the "Matchless" file provided by Grimly on my hosting:

https://www.bwringer.com/gs/matchless/Relay_modification_for_bike_v23_byMatchless-1.pdf

After a bit more pondering, some faint bells started to ring.

George (koolaid_kid) and I were good friends and were frequent guests in one another's garages and homes. As an engineer, George had a very thorough, methodical way of approaching various logical, electrical, and mechanical problems, which you'll see plenty of in this relay document. Our mechanicking styles were different but meshed well; if one of us couldn't figure something out, we could almost always work through it together.

Anyway, back in early April of 2011, George emailed me the following draft document and asked for my feedback. I sent him some general suggestions, but I didn't edit the document. George made some revisions, sent me another version via the dead Microsoft link, then posted it here. Then he made a few more revisions after it was posted.

So please note: this is the first draft, NOT the final version George posted above -- the last modified date on his original post was April 27, 2011, and George emailed me this on March 1, 2011. So there are undoubtedly plenty of inaccuracies and if you follow these instructions to the letter you will probably burn your house down. You have been warned...

But, since the original has been lost to the mists of time (apparently Microsoft expects you to remain alive in order to keep storing things on an Office account) I'll post this for historical reference.

https://www.bwringer.com/gs/george/Yet_another_relay_thread-BW.pdf

I love the use of CAD (Cardboard Aided Design)...

Again, have some respect for the dearly departed and lower your expectations a tad; this is not the final document George created, but unless someone has the final stashed on a musty hard drive somewhere, we may not be able to get closer.

[Burque73]

Thanks so much for posting that, Brian. It is an interesting read though.