81 Seca, starter relay.....

Starter button would sometimes require a few stabs before it caught. Then, it wont engage at all. I took the switch part, determined the blue/w wire was hot, and resistance across contact points near zero. removed the gas tank, & found the rearmost relay on the top of the frame. It has two red/w wires. a black/y wire, & a lt blue wire.(question: is there a junction that goes from the buttons dk blue wire to this lt blue wire??) Taking the cover off the relay, I see that r/w is load, & the b/y, & lt bl activates the relay. I also note whats a small diode, according to the owners book wiring diagram.
If I hook b/y to ground & light bl to pos, I SHOULD activate the relay contacts. Nothing happens, altho everything is connected, no broken wire, etc. I reversed poles, too, in case that odd bit wanted it that way.
Can I replace this with a regular fog lamp type relay, without a diode (or whatever it is) or could this diode be the problem?

I got both a Haynes & the correct xj5650rj owners book, the wiring on the bike in this circuit has a few differences, or Im not reading a Japanese spec diagram correctly. Any insight appreciated....mutt, baffeled, San Diego.....

 

further snooping get me this: at the relay, one of the r&w wires is hot when ignition is on. The sky blue wire is hot at the same time, & goes to zero volts when I push the start button.
I dont savvy how these relays work.
Connecting the relay, & pushin the starter button, still dosnt activate relay......

 

If I recall correctly the only relay with a diode in it is the headlight relay.

Here is a link to the XJ electrical diagrams.

 

i found the relay FAQ- good piece- and I have continuity across the electro coil. Damned if I understand why theres a diode in there.
energise the windings, nothing happens.
Now that I understan the diode function, im gonna make up some jumper leads & try a regular relay of known ability.......im missing something here, damned if I can figure how by pushing the button Im CUTTING voltage......

 

Diode keeps the relay from "chattering" or bouncing wildly when it gets de-energized. You could shoot me the relay and I could test it for you on my Seca. Relays are easily understood only I lack the ability to draw out pictures. Best explained in person or over a real time link with video. Let's see what we can do.

 

In this case, the diode keeps power from backing up the starting system circuit. If you'll look at your wiring diagram, you'll see that the power from the neutral pilot light can flow all the way back to the TCI, through the starter relay, unless you add a diode inline to prevent it from doing so. Yamaha decided the best place to add the diode was inside the starter relay. If this diode wasn't present, the only way to shut off the bike once it was started would be to turn the key to off.

Since you're familiar with continuity, This is what you can do to test your various circuits. Put the bike up on the center stand with the side stand raised. Unplug the pigtail from the starter relay.

The Black/Yellow wire at the starter relay pigtail is a ground for the relay's electromagnetic coil. This circuit is completed when you squeeze the clutch lever. If you hook your continuity tester up to this wire and ground, it should be open until you squeeze the clutch lever. If, after squeezing the lever, you get nothing inspect and clean (or replace) your clutch safety switch.

The Light Blue wire at the starter relay pigtail is a ground for the relay's electromagnetic coil. This circuit is completed when the bike is in neutral. If you hook your continuity tester up to this wire and ground, it should be open until you put the bike's transmission into neutral. If, after shifting into neutral, you get nothing inspect and clean (or replace) your neutral safety switch.

With the key on and the kill switch on, test for voltage at the starter relay pigtail. You should measure 12 volts (roughly) on at least one of the two Red/White wires. If not, you need to check, clean, or replace your 20A Main fuse, fuse holder, ignition switch, and kill switch.

If all of this checks out, take off the right-hand side cover to expose the battery and starter solenoid. (You will want to plug the starter relay pigtail back in for this test.) Find the pigtail for the starter solenoid (Red/White wire and Blue/White wire) and unplug it. Hook your voltmeter to the Red/White wire (coming from the bike, not the starter solenoid) and ground. If the key is on, the kill switch is on, the transmission is in neutral, and/or the clutch lever is squeezed, you should measure 12 volts (roughly). If you don't and everything from above checks out, your starter relay is toast. If you do, then you need to check your starter solenoid circuit. But we'll save that for another posting as this one has grown rather large.

Let me know what you find.

 

Nicely done Don! Another 'attaboy to you!

 

The Black/Yellow wire at the starter relay pigtail .....
checked out

The Light Blue wire at the starter relay pigtail......
checked out.

What, exactly, does the start button control? i thought that (the relay on top)was the starter relay- clearly thats not it. BOTH r&w wires at this relay show batt voltage.

With the key on and the kill switch on, test for voltage at the starter relay pigtail. You should measure 12 volts (roughly) on at least one of the two Red/White wires. If not, you need to check, clean, or replace your 20A Main fuse, fuse holder, ignition switch, and kill switch.........
Both R&W wires at that relay show 12 volts. The fuse box is sound, I took a fine wire brush to the fuse connections....

If all of this checks out, take off the right-hand side cover to expose the battery and starter solenoid. (You will want to plug the starter relay pigtail back in for this test.) Find the pigtail for the starter solenoid (Red/White wire and Blue/White wire) and unplug it. Hook your voltmeter to the Red/White wire (coming from the bike, not the starter solenoid) and ground. If the key is on, the kill switch is on, the transmission is in neutral, and/or the clutch lever is squeezed, you should measure 12 volts .....
it does. and the blue/w wire shows ground, all the time. Huh? Jeez, Im more baffeled than ever. How can a solenoid work intermittantly- to engage the starter, say- if it ALWAYS has power & always has ground on the switch side? Pushing the "start" button made no difference at that bl/w wire at the solenoid under the batt sidecover.

" If you don't and everything from above checks out, your starter relay is toast. If you do, then you need to check your starter solenoid circuit. But we'll save that for another posting as this one has grown rather large."

Thanks for the excellant walk thru. i MAKE wiring harnesses- Brit, Yank, & bevel Dukes. I make SIMPLE wiring harnesses. This one got me flummoxed. What on earth does the "start" button actually control? I got a wiring diagram AND a magnifying glass, & it makes no sense.....but Japanese wiring methods are new to me....

 

And jumpin the cables at the starter solenoid proper gets the starter turning the engine.......

 

Mutt, I'm at work right now so you'll have to wait until I get home for an answer. Sorry...

 

hey, Im sure the Missus appreciates the paycheck........

 

The starter button is the end of the circuit. When you press the starter button, you're grounding the starter solenoid circuit. When you say that the Blue/White shows ground all the time, I'm assuming you're saying you did a continuity test to ground. This doesn't make sense because the engine would crank continuously if that were the case.

Let's do a test. Unplug the pigtail at the starter solenoid (Red/White and Blue/White wires). Take a test lead and hook it to the Red/White wire of the solenoid's pigtail (solenoid side) and hook the other end to the battery's positive terminal.

Make sure the bike is on the center stand and the transmission is in neutral and the key and kill switches are off. Take another test lead and hook one end to the Blue/White wire of the solenoid's pigtail (solenoid side) and then momentarily ground the other end to the battery's negative terminal. At this point, if the starter solenoid is functioning properly, the starter should begin cranking. Test this several times to make sure that it works each and every time. If it starts every time, then we need to look somewhere else for a problem. If it doesn't work at all, or starts to fail after one or two cycles, then the starter solenoid is no good and must be replaced.

Let's leave it there. Let me know what happens after you do this test. The results will determine where we head next.

 

Here's a How-To you and Taint inspired me to write...

How To: Test your starter circuit

Hope it helps!

 

I unplugged the relay under the left side cover. r/w- batt voltage. in neutral, kickstand up, clutch pulled in or out, zero volts on the blue wire with black trace (the other two wires are all black or all white)
To see if indeed its the relay, I made a jumper wire & commected the r/w & the blu/w wire on the harness side. Turn on ignition: headlight came on. Push button- nothing, nothing at all......
the harness on the bike is in good shape, not ratty or oil soaked.
going back into the switch, Im getting only about 7 volts at the blue/w soldered terminal....i had before just checked it with a light. it goes to zero when I push the button.
So, low voltage at the button, AND voltage on both legs of the starter solenoid pig tail, with the ground leg showing 60 ohms.....
Imbeginning to fear its some internal short in the charging system or something else dangerously expensive.
Back to top

 

(in response to query on the starter testing FAQ thread...)
its the one mounted under the ignitor, as per the pic...but its not a Maxim, so there may be a difference there.
the machine has the cylindrical starter relay, next to the starter, the one I mentioned, under the ignitor, & an identicle one on top of the frame, under the rear of the tank. i deduced the under-tank one was tied to the ks & clutch lever. I think.
I guess the next step is getting under the instrument cluster, to .........what?
I dunno.
see why the push button hot wire only got 6 volts.....the lead goes under there....i dread opening that up....
way back when she bought the bike in the first place, I was doing a bunch of service & put a on/off switch in the headlamp ground lead, so you have a way of turning off the headlight in case of some low voltage situation- you can get home by killing the headlamp.
this thing is giving me a headache. Its a damn favor, too: no $ execpt for parts. You'd think Id have that "never volunteer" thing down after the Army, but noooooooo.

 

and ive just found another relay, next to the coils- this one clicks convincingly when I cycle the kill switch.......

 

Based on what I found out last night, posted in my other thread...is your control housing (the one with the start button) mounted on the handlebars?

 

Big duh. I did something I shoulda done a while back. touched the ground wire at the starter button to the blue w wire on the switch. Turned over.
So even tho the contacts were bright & shiney, & cleaned with contact cleaner, & by every usual visual que i was fine, it wasnt.
Jeez.....

 

Hello guys, i have been following your conversations on the starter relays and other issues with our wonderful bikes.. I have an 81 seca J series. I am definietly new to workn on the bike..its been about 20 years since i last did bike repair. I ran the bike the other day and it was fine (despite what i have found so far) i let the bike sit overnight and it rained..when i went out to start it the next day ....

Problem: turn on ignition pops the 10A fuse for signal - bike still will start but main fuse heats up and will pop as well ***warning warning** oh lord help
So - here is what i found
I located a blown inline 5A fuse in headlamp compartment.
I found a black wire fromt he fuel gauge sensor was rubbed bare so i retaped it.
I replaced the fuse holder
I traced my whole loom and everything seems fine. I retaped and went through all the connections.
I became more concerned though when i got to the 1 cylinder (far left clutch side) the plug was black and the exhaust pipe cold.**warning warning** another problem(gonna try replacing plug) i also noted the far exhaust..(throttle side) was also not overly hot - does this mean im running on 2 cylinders..another oh lordy! definetly explain lack of power. I feel so stupid for not seeing this before.

So ya, im following as much of the posts as possible to trouble shoot but i hope one of you can point me in the right direction faster.
thanks for the time
Ride safe
B

 

ok i have been reading for the past 3 hours. i believe i have aquired pandoras box! to qualify.. i have a 1981 seca r, it has 66K... im now cursing. I can see that i am in for a lot of tests.. i just dont understand how the bike sits outside under tarp for 3 months, starts and runs fine (ish) and then over night with the lovely vancouver bc rain it starts popn the signal fuse the next morn.
I am also wondering there is actually a 20A fuse as the main not the 30A that in the bike now?? are all the other fuses 10A?? Im definetly going to add a new fuse box... i replaced the old one with a similar product but even still ... tomorrow im replacing that fuse i found in the headlight bucket and will retrace from there. post comments then and hope i have heard from one of you guru's
here is a link to the bike pic http://vancouver.craigslist.ca/car/588228423.html

i have learned sooo much more since placing the Ad... groan...lol
thanks guys