System Relay Mod

[Burque73]

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

Sure, I'll send it to you.

[Steve]

Thanks, Roger, I got it.

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[Burque73]

Something really weird is happening to my ignition relay setup. Can someone please help make sens of this?

Haven't been able to get the GS started for two weeks now. Finally having time to look into it I found the coils weren't getting power. This is odd, it's been running flawlessly for three years with this setup. No problem, I thought, pop in the spare relay and ride. Problem...spare relay from AutoZone is bad. Ok, ran to Napa and grabbed another, it's bad. Exchanged it for another, it's bad. What is happening?

With the ignition switch turned on:

Original rely gave no power to either coil.

With the AutoZone (Novita) relay coil for cyls 1&4 measured 11.5 v, coil for cyls 2&3 no power.

First Napa (Echlin) relay no power to either coil

Second Napa (Echlin) realy coil for cyls 1&4 measured 11.5v and again the other coil was dead.

Thinking it may be my connections or the plug, I made a jumper from pin 30 to pin 87A to bypass the relay. That powered one coil. Made a double jumper to both 87A and 87 pins and both coils had 12.5 volts. The engine started before I could let go of the button! Without the "choke" even after sitting for two weeks. Is it that common to have bad relays off the shelf? All were 30 Amp relays.

I'd love to leave the jumpers in place since it ran so good, but the coils stay powered even after the key is turned off. Is that bad? Maybe it'll drain the battery over time or hurt the coils, or ??

A couple pics of the first two relays and the jumpers.

20220605_131213 by Roger, on Flickr

20220605_131333 by Roger, on Flickr

20220605_131422 by Roger, on Flickr

[93Bandit]

I'm unsure if it applies to these GS ignition systems but on old points systems in cars you do not want to leave the coil powered continously without discharging it (engine running) because they can over heat and fail.

[Gorminrider]

but the coils stay powered even after the key is turned off. Is that bad? Maybe it'll drain the battery over time or hurt the coils, or ??

NO your coils should not have power key-OFF. YES it's bad and drains your battery. I don't like relays on coils so I'd say give it up. Hook them up per the manual's wiring diagram.
IF you must have a relay, have it Normally Closed and tinker with the kill switch to make it OPEN the relay when it's switched to STOP , or double the path in parallel if you think the loss is in wiring etc etc etc
If you STILL want a relay do what cars do-headlights and horn- which are also affect voltage drop on coils especially starting... but you don't need to on a motorcycle. Motorcycle manufacturers sometimes do do this as "idiot proofing" that is, headlight goes off WHEN STARTING to supply max current and back on when started because people are too stupid to do it themselves...

[Burque73]

Looks like I'll wait till I have another few hours to tinker with this and remove the relay, returning it to stock setup. If relays are that unrelaible I don't want to be caught out in the rain in the middle of nowhere fiddling with this. Lucky for me it failed in my garage, not out in Kansas on a back country road.

Thanks for comments, fellas.

[Killer2600]

No problem, I thought, pop in the spare relay and ride. Problem...spare relay from AutoZone is bad. Ok, ran to Napa and grabbed another, it's bad. Exchanged it for another, it's bad. What is happening?

The relays aren't bad, your setup is bad. Terminal 87 is NO (normally-open) and Terminal 87A is NC (normally-closed). Hooking a coil to each terminal 87 and 87A means that only one coil can work at a time depending on whether the relay is energized or not. For a coil relay mod, both coils should be connected to terminal 87 and nothing should be connected to 87A.

[Burque73]

The relays aren't bad, your setup is bad. Terminal 87 is NO (normally-open) and Terminal 87A is NC (normally-closed). Hooking a coil to each terminal 87 and 87A means that only one coil can work at a time depending on whether the relay is energized or not. For a coil relay mod, both coils should be connected to terminal 87 and nothing should be connected to 87A.

That's odd. I'm sure I followed the how-to writeup exactly. If I wired it up wrong in the first place it shouldn't have ran the last however many thousands of miles it's been. I will look into it some more hopefully this weekend.

[pdqford]

Something really weird is happening to my ignition relay setup. Can someone please help make sens of this?


With the ignition switch turned on:

Original rely gave no power to either coil.

With the AutoZone (Novita) relay coil for cyls 1&4 measured 11.5 v, coil for cyls 2&3 no power.

First Napa (Echlin) relay no power to either coil

Second Napa (Echlin) realy coil for cyls 1&4 measured 11.5v and again the other coil was dead.

Thinking it may be my connections or the plug, I made a jumper from pin 30 to pin 87A to bypass the relay. That powered one coil. Made a double jumper to both 87A and 87 pins and both coils had 12.5 volts. The engine started before I could let go of the button! Without the "choke" even after sitting for two weeks. Is it that common to have bad relays off the shelf? All were 30 Amp relays.

I'd love to leave the jumpers in place since it ran so good, but the coils stay powered even after the key is turned off. Is that bad?

So, here’s my SWAG:
Your original relay went bad. Not sure just what type of relay it was.

It sounds to me like you have one ignition coil wired to pin 87 and the other wired to pin 87A.
It also sounds to me that your pin 30 is hot at all times, even with ignition switch off.

With your replacement coil, when the relay is off, one ignition coil is powered and the other is off.
When the ignition switch is on, the relay is activated, and shuts off one ignition coil and powers up the other.

With your new relay, all you need to do is power BOTH ignition coils from pin 87, and have no ignition coils connected to pin 87A.

Good luck.