Relay burning out and fuse blowing

[posplayr]

While doing some searching for wiring, I came across this post, a little too late:

http://www.thegsresources.com/_forum/showthread.php?236972-DB-Electrical&highlight=db+electrical

My SSH775 was from this vendor.1.) I never saw a conclusion on that post whether what they are selling is actually a series R/R, but to avoid it as a risk. Too late for me, 2.) but is there a way I can test it to confirm it is a series R/R?


Glen

1.) The vendor admitted it was not an SH-775. The email response is in teh thread.
2.) If you have an AC clamp meter you can see the change in current flow in the stator as you change loads liek headlamps.

[posplayr]

Thanks. I was mostly asking about having the idle charging voltage over 14 volts. With my previous R/R, idle charging was low/mid 13's, and would rise up with RPM to mid 14's. With this, I am at 14.2 even at idle. I'm assuming this is a benefit, and reflects a stable charging voltage at all RPMs, but I just wanted to confirm this.

Glen

Ideally you want full voltage all the time. My understanding is that the first commercial series R/R were for Harleys so they would charge when the engine loaped at 300 RPM.
You voltage could be a little higher at idle because of a slightly higher idle RPM.

[glenwill]

Eureka! I think I figured out my relay/fuse burning out problem! My schematic was accurate, but I wasn't seeing what the problem was until I looked at it again today, and it hit me. I'm not sure if I want to burn out an other relay to prove it, but here's what I think is going on:


Here's the relay wires:
Coil +: Orange - return from keyswitch to trigger relay. Was originally feeding the fuse panel.
Coil -: Frame ground
Com: Red - battery side of main fuse
N/O: Orange - feed to fuse panel to power bike


This setup means that both the charging current and operational current are traveling through the main (15A) fuse, since the R/R is one side of the fuse, and both the battery and Relay Common are on the other side. Per other posts on this site, this arrangement results in >15 amps, and will blow the main fuse.


Here's where things get interesting. Once the main fuse blows, the relay coil is still powered by the R/R, and the relay Common still has power from the battery, so the bike keeps running on battery power. Unfortunately, this means the relay coil is the only draw on the R/R. I suspect this alone might burn it out, although I don't really know how this kind of load works. However, the R/R sense wire was connected to one of the lighting feeds, and so was being fed from the battery, and not the R/R!


I don't know how high the R/R voltage will go, but no matter how high it went, the sense will still pickup a lower voltage from the battery, which also would have been steadily depleting as the bike was ridden. When the relay finally burned out, the bike would die as the battery power was no longer feeding the rest of the bike.


One of the symptoms was the battery voltage going down right before it died. Since my mounted volt meter picks up from the ignition circuit, it would have been showing the voltage from the battery. I assume running on just battery with headlights on would deplete voltage somewhat quickly, and when the relay was burning out, I think it would begin to chatter and pass partial voltage through until it died?
I'd love to hear if this makes sense. I know the only proof would be hooking it back up this way and seeing it fail, but I've already replaced the R/R and disconnected the relay, so I don't know if I want to bother just to prove this.

Glen

[OldVet66]

That doesn't sound like your setup is correct. The relay should be triggered by the kill switch, passing 12V+ directly to the coils and ignition from the battery.

[glenwill]

That doesn't sound like your setup is correct. The relay should be triggered by the kill switch, passing 12V+ directly to the coils and ignition from the battery.

You're describing the coil relay mod, but I did a system relay mod. Similar idea, but this bypasses the keyswitch for the whole electrical system.

It's wired as I described, but I should have connected the common to the R/R side of the main fuse.

[OldVet66]

Sorry about that, running on little sleep lately. One question, what would be the advantage of a system relay mod?

[glenwill]

The difference is that the coil relay mod eliminates voltage loss only for the ignition circuit, but for both the key switch and the kill switch. The system relay mod eliminates voltage loss for the entire electrical system, but doesn't eliminate voltage loss in the kill switch on the ignition circuit.

I'm not sure if one is automatically better. I may depend on your current situation. I could not find a way to disassemble the key switch to clean it, and have about .8 volt loss through it. I was able to get the kill switch cleaned up pretty well. So I decided to do the system relay mod to gain .8 volts through the whole system. I do understand that some loss in the lighting system has less effect than loss through the ignition system, but for me this seemed to work fine.

The trouble started when I replaced the fuse box with a new unit, and rewired the system, introducing this problem.

I'd love to hear if anyone thinks my theory on the relay/fuse problem is valid or invalid, as I plan to reintroduce the relay now that I understand what is going on.

Glen

[OldVet66]

I see the point of bypassing problem areas to provide direct battery voltage from the battery to the coils/ignition system or headlight but how do you do an end run around all of your plugs or switches and other connectors. I really have to point out the benefits of DeoxIT D5. I had cleaned up my harness originally when I put my bike together some years ago using CRC contact cleaner and dielectric grease. It's ready for another cleaning after six years or so. I had used the CRC on a set of computer speakers with a noisy volume knob and it lasts for a short time. I used the DeoxIT D5 on it fairly recently and it is still perfect long after regular contact cleaner would have started to fail. There is a good tutorial on cleaning ignition switches available unless your switch is different. This time around I intend to replace all my harness plugs with modern weatherproof plugs, go through all the switches and bullet connectors with DeoxIT D5 and dielectric grease and hopefully won't have to ever fool with it again. The coil relay mod will remain. I made up a set of jumpers that will turn it back to the stock wiring configuration in case of relay failure at the relay.

[glenwill]

Yes, of course. I have cleaned up all of my connectors. They are not the problem.

How did you get your key switch cleaned? That was my specific problem. I could not find a way to disassemble it, and spraying into it closed up didn't do much to help.

[OldVet66]

I haven't done my switch yet because of all the stuff I have to remove, but will be doing it shortly, however I just took the switch off of my '79 GS1000E frame and it is really simple to figure out. The switch housing is held to the underside of the top fork tree with two 5mm Allen head screws on either side of the switch. The whole assembly with wires and plug comes off as one piece. Turn it over and remove the dust cap over the wires. You will see the four wires crimped to the connectors on the bottom. This is definitely a DeoxIT D5 cleanup point because those wires are riveted to the internal contact points and are subject to corrosion. Remove the screw that goes through the wire strain relief clamp and tease the switch out of the key housing. Take a small flat blade screwdriver and pry under the strain relief tab to start separating the white cover from the brown part where the wires are attached, keeping the white part down. Go to the opposite side and do the same and the cover will slide off. Be careful, there are two copper plates one on each side in the white cover that are on springs. They did not come apart. The three bumps on each plate and the corresponding contact points riveted to the wires need cleaning until bright and then apply dielectric grease and re-assemble. Your switch may be a little different but I doubt it's much different. If you need a visual, I could post pictures but it is so simple I'm sure you will figure it out right away. Do not rotate anything in the switch or mark the other side to line it up and everything will drop back together as it was when you removed the assembly.

[glenwill]

1.) The vendor admitted it was not an SH-775. The email response is in teh thread.
2.) If you have an AC clamp meter you can see the change in current flow in the stator as you change loads liek headlamps.

This was a good excuse for me to by a clamp meter, so I found an inexpensive one on Amazon that was highly rated.

I clamped it around one of the stator leads with the bike running, and with the headlights off, it showed 6.4 amps or so. When I turn the headlights on (with high beams on) it jumped to 10.3 or so. Shutoff the headlights, and it goes back to 6.4 amps. I did this back and forth a few times, with consistent results.

I assume this confirms it is a series R/R, just not OEM?

Glen

[posplayr]

This was a good excuse for me to by a clamp meter, so I found an inexpensive one on Amazon that was highly rated.

I clamped it around one of the stator leads with the bike running, and with the headlights off, it showed 6.4 amps or so. When I turn the headlights on (with high beams on) it jumped to 10.3 or so. Shutoff the headlights, and it goes back to 6.4 amps. I did this back and forth a few times, with consistent results.



I assume this confirms it is a series R/R, just not OEM?

Glen

Well not knowing what meter, what R/R and having to correct the units Amps RMS(so the meter setting is in doubt) it appears to follow what you expect from a Series.

[Chrisf]

Just experienced the same symptoms

I know this is an old thread, but thought I should respond.

I too installed the EB fuse panel and system relay mod. It's been working fine for almost 2 years now. Saturday both the fuse and relay blew and I lost all power. I didn't even have the option of running off of battery as was mentioned in one of the posts. It was just an immediate shut off of the bike.

I've replaced the relay and fuse and have not had any issue as of yet. I'm still running the factory R/R and need to run through the charging health tests and see if maybe there could have been a voltage surge. I also need to replace the R/R. Time to start looking for one.

[posplayr]

I know this is an old thread, but thought I should respond.

I too installed the EB fuse panel and system relay mod. It's been working fine for almost 2 years now. Saturday both the fuse and relay blew and I lost all power. I didn't even have the option of running off of battery as was mentioned in one of the posts. It was just an immediate shut off of the bike.

I've replaced the relay and fuse and have not had any issue as of yet. I'm still running the factory R/R and need to run through the charging health tests and see if maybe there could have been a voltage surge. I also need to replace the R/R. Time to start looking for one.

You said relay blew; what does that mean? Coil or contact side?

If the relay is protected (which it shoudl be) there is no way to blow the contacts. The coil can only be blow with too much voltage which would imply your charging system is going open loop.

You need to get a voltmeter and do the quick test ; make sure you are not overcharging.

Also could be your R/R is going out and blowing your main fuse.

It would be a good time to change out the R/R. There is a firesale going on on Compufire R/Rs. You could be a guinea pig and test one out.

[Redman]

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There is a firesale going on on Compufire R/Rs.
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Do tell more....