Low voltage through ignition switch

[koolaid_kid]

I have a problem with low voltage through my ignition switch. I get 12.5v+ from the battery, and if I connect my relay directly to the battery, it works great. When I check the voltage after it passes through the ignition switch (checking at the fuse box) I am getting ~10.5v, which is not enough to activate the relay. I spoke to bwringer about it, and he suggested running a can or two of WD-40 through the switch and rotating the switch to clean the contacts. After a large can of WD-40, and almost 1/2 a can of PB Blaster, there has been no improvement.
Any other suggestions? Can the switch be disassembled to clean it?
This is on my 83 GS1100E.
Thanks.

 

[Sandy]

You should disassemble it. The switch is actually at the very bottom of the assembly and flooding it helps a bit it doesn't really get into the switch itself much. It should be like the one on my GS1000 and you can drop the whole switch out by removing the bolts up underneath it and then the plastic switch assembly is only held in with a small set screw. At this point I didn't completely disassemble the switch/contact assembly, I just flooded it with contact cleaner and rotated it until the cleaner came out clean. Some people disassemble the switch itself for a thorough cleaning but I already have enough little springs and widgets hiding all over my shop. When you rotate the switch pay attention to the orientation of the armature, it can be reassembled 180 degress out. I had the same drop in voltage you do and after cleaning the switch along with the kill switch and any other switches in the circuit like the clutch interlock (which I didn't have) I now only have a .5V drop at my coils.

 

[posplayr]

I have a problem with low voltage through my ignition switch. I get 12.5v+ from the battery, and if I connect my relay directly to the battery, it works great. When I check the voltage after it passes through the ignition switch (checking at the fuse box) I am getting ~10.5v, which is not enough to activate the relay. I spoke to bwringer about it, and he suggested running a can or two of WD-40 through the switch and rotating the switch to clean the contacts. After a large can of WD-40, and almost 1/2 a can of PB Blaster, there has been no improvement.
Any other suggestions? Can the switch be disassembled to clean it?
This is on my 83 GS1100E.
Thanks.

what relay are you using? Is it a 12V device?

 

[Guest]

Jim's right. 10 volts will activate a 12 volt relay.

 

[koolaid_kid]

Jim's right. 10 volts will activate a 12 volt relay.

Not sure who Jim is. It is a 12V Bosch-style relay I purchased off Fleabay. I have successfully used 3 of them on my car with no problems at all. It's not the relay itself because I have tried 2 of them with no luck.
Perhaps I'll get one at Vatozone and try it, it is socketed so swapping it won't be a problem...
Sandy, I didn't think about the kill switch and clutch interlock, yuch...

This all started last year when I noticed my horn was weak, and testing revealed they were only getting 10.5V. So apparently it's been going on for a while.

 

[posplayr]

Not sure who Jim is. It is a 12V Bosch-style relay I purchased off Fleabay. I have successfully used 3 of them on my car with no problems at all. It's not the relay itself because I have tried 2 of them with no luck.
Perhaps I'll get one at Vatozone and try it, it is socketed so swapping it won't be a problem...
Sandy, I didn't think about the kill switch and clutch interlock, yuch...

This all started last year when I noticed my horn was weak, and testing revealed they were only getting 10.5V. So apparently it's been going on for a while.

Hi I'm Jim

Sounds like you should recheck the wiring to your relays. When the relay is activated you should see a solid +12V from the battery (if it is good). In otherwords there should be no drop at the output of the relay as compared to the battery +. This should be the case wether you have the circuit loaded or not.

 

[koolaid_kid]

Hi I'm Jim

Sounds like you should recheck the wiring to your relays. When the relay is activated you should see a solid +12V from the battery (if it is good). In otherwords there should be no drop at the output of the relay as compared to the battery +. This should be the case wether you have the circuit loaded or not.

Hi Jim. I'm George.
I have rechecked the wiring several times. All wired terminals (30, 85, 86, 87) are going where intended. The voltage from the battery is a solid +12.5V. The voltage from the switch is a solid 10.5V. I originally had the relay wired straight to the battery (no switch involved) and it worked just dandy.
I admit to being a bit puzzled as to why the relay does not activate (perhaps because it is a cheap Fleabay product?).
I am also concerned at the low voltage output of the switch, since it also powers my coils, lights, etc. I really don't want to dig into that circuit, but it sounds like I have two tasks: why my cheap relays don't like 10.5V, and why my switch is only sending 10.5V to everything that it powers.
Oh, if only I'd bought that Bandit... (just kidding).

 

[850GT_Rider]

Just a few thoughts...is the negative lead of your voltmeter connected to a good, solid ground? Are you using the same ground for each measurement? Is the grounded side of the relay a good connection?

If everything is not referenced to the same solid ground, the resulting measurements could be leading you down the primrose path......

Finally, have you tried a test light instead of the voltmeter?

 

[posplayr]

Hi Jim. I'm George.
I have rechecked the wiring several times. All wired terminals (30, 85, 86, 87) are going where intended. The voltage from the battery is a solid +12.5V. The voltage from the switch is a solid 10.5V. I originally had the relay wired straight to the battery (no switch involved) and it worked just dandy.
I admit to being a bit puzzled as to why the relay does not activate (perhaps because it is a cheap Fleabay product?).
I am also concerned at the low voltage output of the switch, since it also powers my coils, lights, etc. I really don't want to dig into that circuit, but it sounds like I have two tasks: why my cheap relays don't like 10.5V, and why my switch is only sending 10.5V to everything that it powers.
Oh, if only I'd bought that Bandit... (just kidding).

All those Bosche Type relays are relatively inexpensive mechanical relays. That means when it is activated the only resistance is that of the relay contacts or the external connections.

I dont want to go through all possible combinations of how it might be possibe to miswire the relay, but the single check you could do to confirm if the wireing is wrong is to do the following:

You can not have a voltage drop between pins 30 and 87 when the relay is activated(well maybe if you have a direct short to ground but you would see smoke then).

So if if Pin 30 was the (+)battery and pin 87 was +10.5V then your battery has to be +10.5V and it is not fully charged (assuming normal ignition loads you should be closer to 12.0V with ignition on and engine not running; +12.6-12.8 with the key off).

So if you measure the voltage difference between pin 87 and the Battery (+) (which drives pin 30) and you see any voltage drop (when it is activated) you have the relay wired wrong.

So with the key OFF you might see +12V between pin 30 and 87; but with key ON it should drop to zero. If not it is miswired.

http://www.mp3car.com/vbulletin/faq-emporium/117895-faq-relays-how-they-work-how-wire-up.html

 

[SqDancerLynn1]

I had a simillar problem with my 850. I did not do the coil mod, but I used a relay activated by the ign switch to feed power to the fuse block

 

[Matchless]

I recently found a related reason for the voltage drop. When pulling the small connector plug on the ignition switch, I noticed that one of the tiny male terminals was dark brown while the others were shiny brass. This was the main power feed from the battery. :-k

I pushed out the terminal and it broke in my hands, partially corroded. It has a very weak spot at the locating tab in the brass.

Replaced with a spade terminal connector and all is well. Amazing that such a tiny terminal is used to carry all the current switched via the ignition switch.

 

[posplayr]

I recently found a related reason for the voltage drop. When pulling the small connector plug on the ignition switch, I noticed that one of the tiny male terminals was dark brown while the others were shiny brass. This was the main power feed from the battery. :-k

I pushed out the terminal and it broke in my hands, partially corroded. It has a very weak spot at the locating tab in the brass.

Replaced with a spade terminal connector and all is well. Amazing that such a tiny terminal is used to carry all the current switched via the ignition switch.

It works while it works then it doesnt work

 

[posplayr]

I had a simillar problem with my 850. I did not do the coil mod, but I used a relay activated by the ign switch to feed power to the fuse block

That is really not a bad idea, but for the ignition/coils you still have to:

• get through the fuse box
• go to the right hand start button
• get back to the coils

So you have only taken the least part of the problem.

 

[Matchless]

It works while it works then it doesnt work

Jim, that sums it up nicely!

 

[koolaid_kid]

That is really not a bad idea, but for the ignition/coils you still have to:

• get through the fuse box
• go to the right hand start button
• get back to the coils

So you have only taken the least part of the problem.

That is my goal. It is a 30A relay (40A off, 30A on, standard practice) so I want to be able to power lots of stuff when it starts working.
Since I have measured (who says "To know is to measure"?) that the voltage to all my devices is 10.5V, I want to remedy this. Since P=V*I, I know that nothing is getting the power it is designed to use. Or it is drawing more current than necessary, which is also a bad thing. Oh, why did I buy an old bike, surely an old car would not do this? Oh wait, yes it would, it would just cost more to repair...

 

[koolaid_kid]

All those Bosche Type relays are relatively inexpensive mechanical relays. That means when it is activated the only resistance is that of the relay contacts or the external connections.

I dont want to go through all possible combinations of how it might be possibe to miswire the relay, but the single check you could do to confirm if the wireing is wrong is to do the following:

You can not have a voltage drop between pins 30 and 87 when the relay is activated(well maybe if you have a direct short to ground but you would see smoke then).

So if if Pin 30 was the (+)battery and pin 87 was +10.5V then your battery has to be +10.5V and it is not fully charged (assuming normal ignition loads you should be closer to 12.0V with ignition on and engine not running; +12.6-12.8 with the key off).

So if you measure the voltage difference between pin 87 and the Battery (+) (which drives pin 30) and you see any voltage drop (when it is activated) you have the relay wired wrong.

So with the key OFF you might see +12V between pin 30 and 87; but with key ON it should drop to zero. If not it is miswired.

http://www.mp3car.com/vbulletin/faq-emporium/117895-faq-relays-how-they-work-how-wire-up.html

Well, yes, although I would call it an electro-mechanical device. The coil inside the relay, when activated, turns the relay on. While it is true that the points inside the relay will wear with time, this is a new relay. The connections have all been soldered by me and are solid.
Pin 30 is the battery input, and measures +12.5V. Pin 86 is the switch point, and activates the relay. It measures 10.5V. Pin 87 (active ON) measures 0V. Pin 85, the ground, measures 0, or ground.
I have used my multimeter to check each point of the relay, and they are correct. Key off, I would expect to see +12V at 87a, which I don't use.
I'm not trying to be a smarta@@, trust me. I apreciate the input.

 

[posplayr]

Pin 30 is the battery input, and measures +12.5V. Pin 86 is the switch point, and activates the relay. It measures 10.5V. Pin 87 (active ON) measures 0V. Pin 85, the ground, measures 0, or ground.
I have used my multimeter to check each point of the relay, and they are correct. Key off, I would expect to see +12V at 87a, which I don't use.
I'm not trying to be a smarta@@, trust me. I apreciate the input.

OK so does Pin 87 go to +12V when activated or does it read something else?

 

[koolaid_kid]

OK so does Pin 87 go to +12V when activated or does it read something else?

Still 0 volts, unfortunately. Fundamental issue. To me, that means the relay is not activated. Perhaps I should also monitor 87a?

 

[posplayr]

Still 0 volts, unfortunately. Fundamental issue. To me, that means the relay is not activated. Perhaps I should also monitor 87a?

You are correct; it doesn't sound like it is activated.

Have you tried to run a separate ground to Pin 85?
Sounds like there might not be a ground.

 

[koolaid_kid]

The Final Solution

The Final Solution

So, I tabled this for a while b/c it was clear to me that I was missing something fundamental.
Bwringer came over and checked it, and found two issues:
First, the terminal for 86 pulled out of the socket. He reinserted it and we both heard it click into place. He was unable to get a voltage reading even after that, so he tugged on my connection, and the pigtail wire pulled right out of my connection. We reconnected it, and heard a satisfying "click" when the key was switched on. Everything is good now.
"It worked on my bench" is my only lame excuse. Thanks to everyone for your suggestions, I greatly appreciate it.