push start button....nothing

[gregp]

1981 GS750E
I have been restomodding it for a couple months now. The bike started and ran good before i started my clean up and mods and started up fine several times during the process. Basically the bike is stock mechanically and electrically as far as i can tell. In my process of cleaning, paint touchup etc. i had a lot of the electrical connectors unplugged to remove various items for better access. Now after putting everything back together she wont start...push the start button nada, no click, no buzz, nothing.
Not everything is connected yet such as rear brake light and turn signals. The battery is good. When I switch the kill switch to run position i get 10.6 volts at the switch (seems low?). Push the start button i get nothing. I am not very good with the electricals but i can be talked through just about anything. I have checked that the battery negative lug has continuity with the two grounding points i know of. When i turn the ignition key the headlight comes on, the horn works. but she no start.

I have disconnected and reconnected a lot of connectors and bullet connectors to be sure they are seated well but this at this point i am doing random things and hoping for it to magically start working. Am i forgetting something?

What do i check next?

 

[tom203]

Check at starter solenoid.. Make sure bike is in neutral! Jump across the two big terminals and see if stsrter turns. If yes, then you got problems with solenoid trigger wire,maybe clutch safety switch,back up to kill switch,etc

 

[kerrfunk]

Neutral, and clutch in?

 

[gregp]

Check at starter solenoid.. Make sure bike is in neutral! Jump across the two big terminals and see if stsrter turns. If yes, then you got problems with solenoid trigger wire,maybe clutch safety switch,back up to kill switch,etc

Hi Tom...Yes the neutral thing got me once a few weeks ago! so it is in neutral...but that brings up another question. The idiot lights are not connected so i don't know if the green light is on. Is it possible to be in neutral sort of? the bike rolls like in neutral but she doesn't think she's in neutral?

Jump across two big terminals?...forgive my newbness...which two big terminals?

clutch safety switch? i don't see this on the schematic. although i see a starter disconnect switch on the schematic which i see no sign of on the bike. There is a single bullet connector (grn/yel wire) that looks like that is where it would have been...not sure. but she did start originally so something has changed.

 

[gregp]

Neutral, and clutch in?

it is in neutral...at least i think so...but does the bike think so?...
clutch in?...this is required?...i wasn't aware of that. My CX500 does not require clutch in if in neutral...anyway, clutch in does not help. But if it is required to be "clutch in" even when in neutral i should look at that switch...actually right now it is not even connected and i don't even see it on the schematic. i have an extra yellow wire and an extra brown wire coming out of the main harness. the wires from the clutch switch are both grn/yel and not shown on the schematic...the brown i see on the schematic, looks like tail/brake light and probably not used

 

[Redman]

I dont know specificaly on the E, but on the G, the clutch switch is shown on the factory schematic only as "Interlock". Is in the circuit between the starter button and the starter solenoid.

TO check the battery and the starter motor and the main power connections: Jump between the two big connections on the solenoid.

Yah, 10 volts at the kill swtich sounds low. Check at the battery, if battery is 10 volts, well , need to deal with that first.

 

[Steve]

clutch in?...this is required?...i wasn't aware of that. My CX500 does not require clutch in if in neutral...

That is because Honda chose to go with a more-complex logic circuit. If the bike is in Neutral, you do not need to pull the clutch. However, if the bike is in gear, you DO need to pull the clutch. My Golddwing operates the same way.

Suzuki chose to go with a much simpler idea. Pull the clutch every time, whether in Neutral or in gear. It is easy to bypass this "safety" feature so you don't have to pull the clutch any time. It's possible that a previous owner might have already done that for you.

.

 

[tom203]

"Jump across two big terminals?...forgive my newbness...which two big terminals?"

Look at this pic of starter solenoid... You can jump /bridge across the two big terminals with pliers or something. One big terminal gets the wire going to positive battery,the other big guy gets the wire going to starter motor. When these are connected,voila, the starter spins.
Note also the small yellow wire with green stripe... this is the trigger wire for the solenoid which runs up to clutch safety switch. Note also the small ground wire connection.

 

[Steve]

Note also the small ground wire connection.

Please also note that the ground wire connection does not exist on most GS solenoids.

The ground connection is formed through the case and the screw that mounts it to the bike.

However, most solenoids are mounted on a rubber-isolated battery box, so there is a ground wire from the mounting screw to the chassis.

.

 

[kerrfunk]

One time when I was about nineteen years old I was back from college and had a dentist appointment or something. I jumped into my dad's car and it would not start, no engine turning, nothing. I had to take my mom's car.

Dad's car was a manual transmission and I had forgotten to put the clutch in and that's why it wouldn't start.

When I was working on my starter recently I wrapped a wire around the clutch lever so I could check the start without both hands on the bars.

 

[gregp]

"View attachment 50022Jump across two big terminals?...forgive my newbness...which two big terminals?"

Look at this pic of starter solenoid... You can jump /bridge across the two big terminals with pliers or something. One big terminal gets the wire going to positive battery,the other big guy gets the wire going to starter motor. When these are connected,voila, the starter spins.
Note also the small yellow wire with green stripe... this is the trigger wire for the solenoid which runs up to clutch safety switch. Note also the small ground wire connection.

OK...so bridging the terminals on the starter solenoid didn't work but it did produce quite a light show. There were some sparks but nothing else happened. In the pictures you will see i have only the key switch and the kill switch connected. You can see that the grn/yel wire coming from the kill switch connector has a bullet type connector a few inches away and that connects to a grn/yel wire coming out of the main harness. This is the way i believe the PO had it wired which i assume bypasses the clutch switch (wires you can see in my fingers). Looking back at some pictures i took when disassembling i think the clutch switch was not connected and that's how it was working. I have attached some other pics that show the starter solenoid...there is a ground wire from the negative lug that comes from the harness. In the other picture you can see the harness with the blk/wht wires...one to the starter solenoid lug and one to the chassis gnd at the battery box mounting screw.

The second and third picture won't upload;(
will try in additional posts.

 

[gregp]

second photo...

 

[gregp]

third photo...

 

[tom203]

"....so bridging the terminals on the starter solenoid didn't work but it did produce quite a light show."

Well, current was going someplace... Are you sure your bridging device wasn't grounding out on solenoid frame? Starter motor takes about 80 amps, so you'll get some sparks across solenoid terminals during bridging fun. As a no sparky alternative, use a smallish jumper wire from battery positive to that yellow green stripe contact on solenoid - should click and starter should spin. Seems unlikely that your starter motor has failed after your cleaning.

 

[gregp]

"....so bridging the terminals on the starter solenoid didn't work but it did produce quite a light show."

Well, current was going someplace... Are you sure your bridging device wasn't grounding out on solenoid frame? Starter motor takes about 80 amps, so you'll get some sparks across solenoid terminals during bridging fun. As a no sparky alternative, use a smallish jumper wire from battery positive to that yellow green stripe contact on solenoid - should click and starter should spin. Seems unlikely that your starter motor has failed after your cleaning.

using needle nose pliers open and touching the tips to each of the lugs make some sparks and almost welds the pliers to the lugs...a wire from the positive battery terminal to the grn/yel pad on the solenoid does nothing.
i connected the clutch switch and i put some leads into the kill switch connector on the orn/wht wire and the yel/grn wire to measure some voltages...see pic
with key on and kill switch in run position no voltage there...when i pull the clutch in the voltage goes to -2.39V...i don't know what i'm doing...just more information
...can't attach more than one photo so there will be two more posts

 

[gregp]

Key on....kill switch in run position...clutch not pulled in...no volts

 

[gregp]

pull in clutch...-2.29 volts????

 

[gregp]

...i should add when i push the start button at that point the volts go to .1V (i think....something close to zero anyway)...

 

[Redman]

DOnt know what to say about your variuous observations.


But this one, seems like a good observation/symptom that we can work with:

..... ...... ....... ......... ...... ...... ....a wire from the positive battery terminal to the grn/yel pad on the solenoid does nothing. ..............s

Not even a hint of a grunt, dim the head light, not even a faint click ....?
Well then I suspect one of two things:
1- Solenoid is bad, is doing nothing.
or
2-Solenoid is not grounded. Solenoid gets its ground from being mounted to the battery box, but the battery box may not be well grounded to the frame, so is suppose to be a blk/wht wire from the bikes wiring harness that is connected to the frame and to the bolt that mounts the solenoid. Look to see if that wire is there at bolt of the solenoid, and even if it is, the other end may not be well grounded to the frame, so add your own wire from that solenoid bolt to the bike frame (or battery negitive).

.

 

[Redman]

Did you ever get the battery charged up to more than 10 volts....?

.