Hard to get a handle on this

[chiz]

Happy Sunday to all
  While waiting for spares I decided to do the ignition coil relay mod. After  days trying to decipher the posts descriptions and photographs I have managed to construct a harness with all the stuff, relay fuse ground Y piece Jumpers and know if I plugged it in it would likely do the job. I just wish someone had drawn an actual wiring diagram with everything labeled red wire gray wire 30 terminal  65 terminal etc and rough length of wires in just black and white would have been much easier to understand and build. It was only at the second half of the   original mod posting that someone decided to clear up some stuff that it became a little less foggy......   
   MY SERIOUS LACK OF ELECTRICAL UNDERSTANDING prevents me from having a clue how this actually works so I am hoping  that someone may have some answers.
1 when the ignition key is switched on what is the course that the 12v takes to power up the ignition coils without the mod?
2 when the key is switched on with mod connected and before the starter button is pressed what course does the12v take or flow if different to question 1?
3 when the start button is pressed through what terminals on the relay is currant passing to activate the RELAY COIL for the duration of the ride and how is this being made permanent for the duration when the start button is no longer being pressed?
4 I assume that the supply for IGNITION COILS is being downloaded from the fused wire connected to the + on the starter solenoid if so what course does it take through the relay?
5 once ignition is switched off the circuit colapses I guess, juice no longer flows from batt to sol to ignition coils.
Please help it would be appalling to hook all this up and not know what is really happening.
Thanks
          Chiz

[rktmanfj]

Maybe this will help:

http://electronics.howstuffworks.com/relay1.htm

Then, here's a coil relay write up:

http://biquetoast.com/assortedDocs/coil_relay.pdf

HTH

[chiz]

Ok I actually think I get it now After watching a video 85 and 86 are the relay coil terminals 87 87a and 30 are the switched power terminals after looking at the diagram on the link above I get it.
I had not figured out that the trigger voltage was coming from the disconnected plugs up in the steering head and when the key was switched on the the relay coil is energised and now battery juice flows through the relay out terminal 87 to the coils.... I GOT THIS RIGHT???
Chiz
   Thanks

[rktmanfj]

Sounds like you have the idea... here's one more link:

http://www.ripper1.com/tech/wiring.php

[chiz]

Hi
I am getting a little stick on another forum about this subject mainly is... if you are getting less than 12v at the coils then there is a fault with the ignition system. The maker has not designed the coils to work on 9 10 or 11v but 12v so therefore there must be a fault so where is the fault in the system/ and did Yamaha know about this.
Chiz 

[movenon]

Hi
I am getting a little stick on another forum about this subject mainly is... if you are getting less than 12v at the coils then there is a fault with the ignition system. The maker has not designed the coils to work on 9 10 or 11v but 12v so therefore there must be a fault so where is the fault in the system/ and did Yamaha know about this.
Chiz 

umm, All the FJ's came off the show room floor operating with the same voltages and all of them ran just fine and still are (well most of them).  The coils and other devices see less than 12 volts all the time. There is voltage drop in each connector, switch, wire length etc.. I am more than sure the factory took that into account. They also probably took the fact that the alternator can put out up to 15 volts (upper service limit according to the service manual). So I guess you could see a voltage up in the 15 volt area under extreme conditions. Will 12 volt devices work at 12.5 -15 volts, mostly yes.  How long is another story. The engineers undoubtedly took "service life" into account. I like a brighter headlight and have one, but its service life is half the stock bulb. I live with it.

I am not bad mouthing using the relays, if your engine is modified or have some valid reason to use them,  great. I have a relays for added horns, extra running lights and thinking about one for heated grips, all of those have higher current drain and I do not want to run large switch's and run excessively large gauge wiring around.  Those items can see 11 to 15 volts at times. There life expectancy's will be reduced to some degree if operated at higher voltages. Those items are not used all the time and none of them are critical to my bike running.

I feel that sometimes people will add the relays to the coil circuit because they have unsolved ignition problems. You also add another fail point in the ignition system. Just crap to think about while throwing bits of thermite into the digital camp fire. 

George

[Dads_FJ]

Hi
I am getting a little stick on another forum about this subject mainly is... if you are getting less than 12v at the coils then there is a fault with the ignition system. The maker has not designed the coils to work on 9 10 or 11v but 12v so therefore there must be a fault so where is the fault in the system/ and did Yamaha know about this.
Chiz 

umm, All the FJ's came off the show room floor operating with the same voltages and all of them ran just fine and still are (well most of them).  The coils and other devices see less than 12 volts all the time. There is voltage drop in each connector, switch, wire length etc.. I am more than sure the factory took that into account. They also probably took the fact that the alternator can put out up to 15 volts (upper service limit according to the service manual). So I guess you could see a voltage up in the 15 volt area under extreme conditions. Will 12 volt devices work at 12.5 -15 volts, mostly yes.  How long is another story. The engineers undoubtedly took "service life" into account. I like a brighter headlight and have one, but its service life is half the stock bulb. I live with it.

I am not bad mouthing using the relays, if your engine is modified or have some valid reason to use them,  great. I have a relays for added horns, extra running lights and thinking about one for heated grips, all of those have higher current drain and I do not want to run large switch's and run excessively large gauge wiring around.  Those items can see 11 to 15 volts at times. There life expectancy's will be reduced to some degree if operated at higher voltages. Those items are not used all the time and none of them are critical to my bike running.

I feel that sometimes people will add the relays to the coil circuit because they have unsolved ignition problems. You also add another fail point in the ignition system. Just crap to think about while throwing bits of thermite into the digital camp fire. 

George

George, your response about higher current vs. life expectancy got me thinking... Old GMs (and maybe other manufactures), had a START circuit from the starter to the coil when starting the vehicle, but when RUNNING voltage was dropped to the coil via ballast resistor (or ballast wire).  When this theory is applied the the FJ, one could energize a relay from the start switch producing a higher voltage to the coils for good starting, but when running the original circuit would be in place for longevity. 

[movenon]

That makes more engineering sense John. There is a large voltage / current drop when the starter is engaged plus any misc lights if any drawing down the system. Getting full voltage to the coil is what you want but after she is up a going you need to regulate or limit that voltage to probably prevent over heating the internal coil windings. All theoretical stuff to think about doing when doing electrical mods.

I keep going back to the fact when the FJ came off the show room floor she ran great and if a lot of our bikes ran that good today most would be happy. Not as many "design errors" as one might think.  Lack of maint., corroded connections, old parts are probably most of the problems.  

When the bike is new everyone keeps up with the maint and repair and as it gets older and sold to new owners it soon gets to a point where nothing is done unless it is broken, then it gets "jury" rigged to get by, sold to another owner and by then it's an old beater and sits out side in the snow and rain rotting away, 30 years later she shows up here for some TLC. By then about everything needs to be replaced.... What do you mean the swing arm was suppose to be lubed ...... Carbs synced every year ? Check the head bearings, heck why do that, Why lube the chain.... and the story go on  
George

[ribbert]

Hi
I am getting a little stick on another forum about this subject mainly is... if you are getting less than 12v at the coils then there is a fault with the ignition system. The maker has not designed the coils to work on 9 10 or 11v but 12v so therefore there must be a fault so where is the fault in the system/ and did Yamaha know about this.
Chiz 

Yes, there is a fault here and Yamaha didn't know about it.
It's the wankers on the other forum.
Take a look at your car, whatever you drive. Everything is operated by relays, from the factory. Voltage drop by the time the battery power finally gets to the device is an acknowledged issue.

If there was any "fault" by the Yamaha, AND the others in that era, it was not acknowledging that although bikes are physically smaller and wiring more direct, voltage drop is still a common occurrence and age and storage conditions do compound the issue.

Nor would I call it a "fault", things just work a bit better through a relay.

I don't agree that relays add another failure point, just the opposite. Relays are reliable and add service life to the component they control by delivering the voltage they were designed to operate at and eliminate failure points.

Noel

[chiz]

It would be interesting to have a mythical brand new vacuum sealed FJ to see if indeed there is a voltage drop. so what has been touted as the cats meow of ignition mods on the www  is just a lot of internet bunk. I think the battery goes in tomorrow to see what the voltage is at rest before I hook this contraption up
Chiz

[chiz]

Getting ridiculous low voltages everywhere I check 10.2 at coil 10.8 at the TDI... no 12v anywhere except the battery, should I be using an analog meter?
Chiz

[RichBaker]

Doesn't matter what version of VM you use, what you see is what you got.....  You are using the battery neg term for ground?  There's a lot of voltage drop in the stock wiring and connectors.

[ribbert]

Getting ridiculous low voltages everywhere I check 10.2 at coil 10.8 at the TDI... no 12v anywhere except the battery, should I be using an analog meter?
Chiz

My comment yesterday:

"Voltage drop by the time the battery power finally gets to the device is an acknowledged issue".

"voltage drop is still a common occurrence and age and storage conditions do compound the issue".

"Take a look at your car, whatever you drive. Everything is operated by relays."


Rich's comment today:

"There's a lot of voltage drop in the stock wiring and connectors".


The low voltage you are finding is the very reason to run these things off relays and type of voltmeter has no bearing on this.
The relays will deliver full power to the unit.

Noel

[fj11.5]

Use relays mate, well worth the effort , I have numerous ones on effie, lights, horns , coil etc,  when fitting the airhorn, the oem horn wiring wouldn't even run it, and the oem horn was barely beepy , fitted relays and bwaaaaaapp  horns so loud your ears bleed ,,, oh, and they make lights work as they should rather well tooo


Rod

[Pat Conlon]

.......so what has been touted as the cats meow of ignition mods on the www  is just a lot of internet bunk.....
Chiz

Chiz, I don't understand this comment, so please explain it to me.

Did someone on this forum, or on another forum, tell you that the coil relay mod was "bunk"?

.... Or is that just your opinion?