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Buggered it up re mystry relay

Started by chiz, October 11, 2021, 12:30:18 PM

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chiz

fRUSTRATING I did it again and don't have a clue what happened. The mystry relay is connected back to the harness and it goes click when I turn the ignition on headlight and tail light come on as well as neutral light when I press start  button oil light comes on and NOTHING no start motor? OK when I have the switch OFF and unplug the blue /white wire going to the solenoid and I touch to the frame the starter works not sure why but electrical wizards will know the reason for this no doubt. The handle bar switch is turned to run is there some kind of seat switch  preventing starting?
    Could the jumper from black to blue/white in my original post be not making connection anymore? or has the system decided to go FU I'm going to mess with you head because you messed with me?  HELLLLLLLLP   Chiz

T Legg

It sounds like the starter cut off relay is not energized. When you push the starter button it grounds the blue white wire on one side of the starter cut off relay ( it also provides a ground for the oil light through diode 27 causing it to light up) if the starter cut off relay is energized then the blue white wire on the other side of the relay contacts is connected to ground and that wire is connected to the starter relay ( starter solenoid ) allowing it's contacts to close and run the starter.
The starter cut off relay is energized on the positive side by the kill switch and the ground side by either the clutch switch and the kickstand switch also being closed connecting it to ground or it's grounded through the neutral switch when the bike is in neutral.
It appears that the factory manual wiring diagram has a mistake and shows the L/Y wire and the B/Y wire connections to the clutch switch #41 reversed. I corrected it on the diagram . I also put the color codes for the wires on the side. The second diagram is the one included with the owners manual. It shows all the plug connectors and the actual connection points on the bike. You can see on that diagram that the flasher relay and the starter cut off relay are combined into one relay.
T Legg

chiz

Thanks  This is nuts all I did was take the batt out disconnect the wires under there spray them off with cleaner re-grease them and put everything back together. Kind of reminds me of my daily driver a looong time ago an Austin Wosley had to wack the fuel pump in the trunk with a stick then it would give a familar sound kachunk kachunk. The stick no longer worked so I found another pump kachunk came back even pulled the hose off of the single SU carb to see if fuel was flowing ....no dice. Well the contact breaker decided to deliver it's last spark at the same time  go figure' Same kind of double misshap with this perfectly working bike....... Don't fix what's not broke.
Chiz

ribbert

Quote from: chiz on October 12, 2021, 06:44:01 AM
....Kind of reminds me of my daily driver a looong time ago an Austin Wosley had to wack the fuel pump in the trunk with a stick then it would give a familar sound kachunk kachunk. . Don't fix what's not broke....
Chiz

Haha, the pump you refer to is the infamous SU pump, fitted to everything British for half a century and the bane of every motorist's life at some point.

When I started work in 1969, Australia's car fleet was still largely British and our own US derived auto industry barely 20 years old and still without small or luxury segments so the nation's mobility was somewhat dependent on these pumps.
They were an impulse or interrupter type pump that suffered rapid points failure from excessive arcing (later improved) and to some extent, the materials of the day. Bakelite parts, soft alloy and typically English fine threads, any or all of which were a trap for the DIY mechanic, often remaining serviceable just long enough after a "repair" to get you to the most inconvenient place and time and then fail completely. That's assuming of course the rest of the cars Lucas electrics allowed you to get that far. It was common for MG owners to leave the battery access panel behind the seat loose for speedy access to tap the pump into action. Fitting a second pump (same type of course) was common practice.

Now, nearly a 100 years later, we are not only still using the same pump on our FJ's, but a version of it that had become outdated 20 years earlier, one still fitted with points!
Just like I did to my cars as a youngster, I still occasionally have to tap the FJ pump into life if the battery is getting tired or a bit down on voltage or if it hasn't been used for a while, but I can't complain, it does have 270,000km on the pump with nothing more than 2 or 3  points clean ups in it's life.

I know dissenting opinions are unpopular here but I'm not a fan at all of the practice of disconnecting every electrical connection you can find for cleaning. The integrity of connections can be established without wrenching everything apart, with the right tools you can do this without disturbing the loom and nearby wires, and with greater success. This is not directed at you Chiz but your post brought the subject to mind.

The scattergun approach can just lead to more trouble, and often does. Do a bit of research on diagnostic techniques and buy a test light, a good one will have a hardened, surgically sharp and narrow point that will easily penetrate insulation and fit into terminal blocks (and they're cheap) I also recommend a self powered (battery) test light for checking continuity and earths.

That nano second of a flicker of a test light is often the clue that finds the fault, the same event registering on a multimeter would almost certainly go unnoticed because you're looking at what you're doing and not the screen and even if you are, you can literally miss it in a blink. The test light illumination is where you're probing, you can't miss it.

It is often said of enthusiast owners, by mechanics..... "It wasn't broken but he fixed it until it was"  :biggrin:

IMO (and my mechanic agrees)

Noel
"Tell a wise man something he doesn't know and he'll thank you, tell a fool something he doesn't know and he'll abuse you"

chiz

Points all taken thanks for your input... Because I am so shitty at electrical stuff it takes me days(weeks) to get it done. Right now I would like to ask, what is the collective opinion as to why the trigger wire to the start solenoid is dead when I press the start switch? Surly this wire did not decide to to disconnect itself from the harness at some point?
Thanks

Pat Conlon

Rarely is it the fault of the wire*, more often, the switch.

* unless your wiring harness has been hacked, then all bets are off.
1) Free Owners Manual download: https://tinyurl.com/fmsz7hk9
2) Don't store your FJ with E10 fuel https://tinyurl.com/3cjrfct5
3) Replace your old stock rubber brake lines.
4) Important items for the '84-87 FJ's:
Safety wire: https://tinyurl.com/99zp8ufh
Fuel line: https://tinyurl.com/bdff9bf3

chiz

No hacking of harness as far as I know only the IGN coil work around and added relay.

T Legg

Quote from: chiz on October 13, 2021, 03:46:19 PM
No hacking of harness as far as I know only the IGN coil work around and added relay.

    Chiz you should take a picture of the relay and the added jumpers. Following are pictures of the kickstand relay which is by the battery and starter relay. This relay should not have a blue and white wire to it though it does have a blue yellow wire a black white wire a black wire and a red white wire . The next picture is the relay unit which is located under the fairing next to the fuse box and contains both the starter cut off relay and flasher relay. That is the relay that should have the blue white wires.
The starter relay magnetic coil gets its positive 12 volts directly from the red wire coming from the battery . When you disconnect the blue white wire from the starter relay(starter solenoid) and ground it to the frame you are providing a path to negative ground for the positive twelve volts to flow and the starter engages. When the blue white wire of the solenoid is connected up it goes to the contacts of the starter cut off relay . When those contacts are closed the blue white wire is connected through the contacts to the other blue white white wire which runs to the starter switch. When the starter switch is pushed it connects that blue white wire to ground through the black wire at the starter switch and the starter turns over.
The fact that the oil light comes on when you push the starter switch indicates the starter switch is connecting to ground when pushed and allowing the light to work but the blue white wire circuit is interrupted somewhere on the way. That interruption could be from the contacts of the starter cut off relay either being bad or the starter relay is not energized leaving it's contacts open . It could also be from a bad connection in one of the connectors or a broken wire. To figure it out you have to  check the wire at each point along the way until you find the problem . Since your starter relay (solenoid)  has the positive voltage present your are looking for a break in the circuit to ground . If you put your red meter lead into the unplugged blue white wire of the starter solenoid and touch the black meter lead to ground you will read 12 volts . To check for your problem you touch your black meter lead to each connection of the blue white wire on its way to ground through the connectors through the contacts of the starter cut off relay then through the starter switch to the black wire leaving it which is connected to ground until you read twelve volts . If you find the problem is open contacts of the starter cut off relay then you have to see if the coil of that relay has twelve volts to it and is energized.
My corrected factory wiring diagram was wrong still. I have now corrected my corrected version at the clutch switch .
      If this is still confusing you could give me a call when you are by your bike with a copy of the schematic and a meter and I could talk you through it.
T Legg

chiz

Wow man thanks.... yes this is the relay under the seat that is jumped from black to blue and yellow..   sorry these  old eyes are seeing white instead. I will try to preform the test you describe soon  I am assuming they are done with ignition switch ON?
Chiz

T Legg

The test should be done with the key on and the starter switch pushed in .

Where I said the contacts of the starter cut off relay could be bad or the starter relay isn't energized I meant the starter cut off relay isn't energized .
Good luck.
T Legg

chiz

Hi is there some folk out there that can teach me how to test the starter cut off relay, I can't feel or hear anything clicking when I turn the ignition on or press the start button. If i ground the blue and white from the plug that plugs into it and flasher relay I can get the starting motor to turn over. Chiz

T Legg

I posted a picture of the relay unit and the plug that connects to it. The starter cut off relay portion of the relay unit is the four pins to the left of the bottom center pin . The two bottom pins of the starter cut off relay are the magnetic coil connections. If you measure across the pins with your ohm meter you should read about 250 ohms . The two top pins are the contacts of the starter cut off relay . They are open (not connected) until 12 volts are applied to the coil by the red white wire and the black yellow wire making the contacts close together. The two blue white wires of the plug are connected together by the relay contacts when energized.
With the connector unplugged and the key on and the kill switch in the run position you should read 12 volts positive to ground at the red white wire. The black yellow wire connects to ground either through the nuetral switch when the transmission is in nuetral and or through the clutch switch and kickstand switch being closed at the same time.
So if you have the key and kill switch on and the bike in nuetral you should read 12 volts between the red white wire and the black yellow wire at the plug connector. You should also read 12 volts between the R/W and B/Y wires when the kickstand is up and the clutch is pulled in closing the kickstand and clutch switches and connecting the B/Y wire to ground (from your description your kickstand switch may be bypassed and therefore always closed ).
When the starter cut off relay is energized and it's contacts are closed the blue white wire from starter relay is connected to the blue white wire that goes to the starter switch . When the starter switch is pushed the blue white wire is connected to ground through the black wire of the starter switch and the starter will run .
If you jump the two blue white wires together at the plug that connects to the starter cut off relay with the connector unplugged from the relay you should be able to operate the starter by pushing the starter switch when the key is on. Be careful the bike will start in gear with the blue wires jumped together. I hope this helps.
T Legg

chiz

Here again did the ohomage test a while back got around 130 ohms and quite a bit less for the flasher relay. The RW and BY test revealed a jumping meter reading milli volts when I removed the probe from BY wire and went to ground with it I got 10.5v dc. The clutch lever stand test I read 10.5v between the RW and BY ??  Could there be a bad diode? Reason for voltage drop could it be the fan which is part of the aftermarket headlight bulb?

   Chiz

T Legg

If you had the key and kill switch on but the bike in gear and the clutch not pulled the RW and BY test results are correct because you have positive twelve volts at the RW wire but no path to ground yet on the BY wire. Then next you put the kickstand up and pulled the clutch lever in and read 10.5 volts between RW and BY that is correct.
Now with the key and kill switch still on and you release the clutch lever and shift the bike into neutral you should read 10.5 volts also.
 If you have the condition where you have the 10.5 volts between RW and BY and you plug the relay into its connector then the relay coil that you already ohmed out ok should energize and close the contacts of the starter cut off relay. If those contacts close and you push the starter switch and it doesn't turn over you will need to verify the relay contacts actually closed and you have twelve volts (or 10.5 ) on the blue white wire that goes to the starter switch. If you do have the twelve volts on that wire then the relay is good and you need to trace out that blue white wire through its connectors to the starter switch. You know the starter switch is working because when you pressed it the red oil light came on.
   Any way that's the next step. You always have voltage drops through the resistance of the wires and connectors and that is why your voltage readings are lower than twelve volts.
   Fixing electrical problems over a forum is like playing chess by mail but your working through it and will find the problem if you just follow the circuits through.
T Legg

chiz

Thank you.
  Can everyone assume that in the wire diag above that all switches and contacts are drawn in the position before the rider turns the switch key on and pops up the kick stand? I take it the stand switch needs to close for the bike to start?
Chiz