Strange briggs electrical issue

[kevjns]

Hey All

Have a strange problem with my Bahia ride on mower the engine is the Briggs diamond ic 13.5hp

27M707 - 1187 - E1 Code:980413ZB

Image here https://goo.gl/photos/aFMVtm5a96UF69L66

I have swapped in a complete new loom most of it was self explanatory to fit as it was mainly safety switch plugs etc.

now if I put the key in and turn to 3rd stage start, the engine cranks as it should but even it there is no one on the seat.

if I push either forward or back pedals it wont start, if I leave the handbrake off it wont crank which is as it should be but the seat switch makes no difference.

the loom is new also replaced the seat switch with a new one. got my fluke meter on it and it tests fine.

also strange is that if I turn they key back from last stage it tries to start???.

its had the following new parts all genuine fro briggs and stratton:

new key ignition switch
new solenoid
new fuse holder
new looms
new starter motor
new fly wheel and key
valves checked and set perfectly.

I also noticed there was no wire from the ignition coil as a stop the spade was half missing so I've soldered a wire on but unsure of its location.

any help would be greatly appreciated

kevin

 

[Lawnranger]

One factor to keep in mind is that new does not always equal good. You must verify by testing that all parts of the circuit are good. Side note: a friend of mine restored a Jeep and bought a new loom and had problems with the lights. Turns out the manufacturer of the loom reversed two wires. My friend spent countless hours tracing the problem but he wanted it fixed and his persistence paid off.

The fact that the engine will crank without the seat switch is not out of the ordinary. I own a Grasshopper mower and it will crank without someone in the seat. However, if the blades are engaged and you raise up out of the seat the engine dies. The loom you purchased may be set up different from the original and you should call the manufacturer to verify.

One problem I saw at first glance of your picture is that you have a four terminal solenoid with only three wires connected. Is there a fourth wire? Should the machine have a three wire solenoid? The only way for that setup to crank the engine when turning the ignition switch back from start to run is that something (the switch maybe) is sending a signal to the small wire on the solenoid during the process. Remember, new does not equal good in all cases. If you need a test procedure for the ignition switch, just ask. From what you describe the solenoid is doing its job and I'd be suspicious of the ignition switch first.

The kill wire from the ignition coil goes to the "M" terminal (magneto) on the ignition switch. When you turn the ignition switch to the off position internally it connects the "M" terminal to the "G" terminal (ground) to kill the spark.

 

[kevjns]

Thanks for the reply ive put some photos of how it is now link below as mowers in front of me.

https://goo.gl/photos/1DKdinc4ko1sgAar8

Came with 4 way solinoied in pics i have some wires not attached as im trying to find there location now.

 

[kevjns]

Progress at last. Ive now found iut i have a few wires missing from the loom firstly theres extra orange in my old loom dont know what the symbol is but theres also diode in the wire.

its wire 19 to 50 then gose to solenoid
Pics https://goo.gl/photos/vT5xaGZASou5rPix6

This must be why im getting so many issues?

 

[bertsmobile1]

The wiring systems are all basically the same.
power goes from the hot side of the starter solenoid to the ignition switch usually a red wire and has a fuse in it.
The ignition switch bridges the B ( Battery) terminal with the S ( Start ) terminal.
The colour changes , usually yellow or orange then goes to the blade switch, change of colour again then to the brake switch , changes colour again then to the starter solenoid.
Thus the engine can not crank unless the blades are turned off & the parking brake is turned on.

The spark is controlled by earth wires, lots of them all working in parallel and some times in groups ( seat + brake ).
On some systems and yours seem to be one of them they also run the earth wires to the starting solenoid, mainly to stop owners bypassing safety switches and in most cases it is the seat switch that supplies the earth link to the starter solenoid.
In most cases this can be bypasses by simply putting loop from the solenoid mounting bolt to the neg terminal on the solenoid.

Do yourself a favour and print out several copies of your circuit diagram.
Then colour the individual circuits so they stand out from the other wires .
You have 3 separate circuits.
1) starter motor circuit
2) spark circuit
3) alternator circuit includes lights
Now check each circuit in isolation from the others.
Use come coloured felt tip pens and colour each wire on the diagram the same colour as the wire on the mower as you find them.
Work backwards from the starter solenoid to the starer switch. it is ease to do that way.

Remember for the starter to work, you must have a closed loop from battery to the small terminals on the solenoid.

For the spark to work you must have an open circuit between the coil and every thing the wire is connected to.

 

[kevjns]

I can start it just the seat safty switch isnt working. Also whats the symbol on the diagram it isnt a buzzer as thats 108 on the diagram

 

[Lawnranger]

Progress at last. Ive now found iut i have a few wires missing from the loom firstly theres extra orange in my old loom dont know what the symbol is but theres also diode in the wire.

its wire 19 to 50 then gose to solenoid
Pics https://goo.gl/photos/vT5xaGZASou5rPix6

This must be why im getting so many issues?

Wire 19 is coming off the "L" (lights) terminal of the ignition switch. Wire 50 has a diode to prevent back-feed. Since the power is coming from the "L" terminal it is probably for the lights and not the starter solenoid. The wire coming off the "S" terminal starts as wire 16 but changes as it goes through the fuse and switch(s) along the way and that wire should go to the starter solenoid. Difficult to tell with only part of the schematic.

 

[Lawnranger]

I can start it just the seat safty switch isnt working.

See post #2, paragraph #2 of this thread.

 

[Lawnranger]

Also whats the symbol on the diagram it isnt a buzzer as thats 108 on the diagram

What diagram and what symbol are you referring to? If it's the schematic you posted a picture of, 108 is not showing up for me to see. You will have to be more specific.

 

[kevjns]

What diagram and what symbol are you referring to? If it's the schematic you posted a picture of, 108 is not showing up for me to see. You will have to be more specific.

Hi

Ive marked the symbol in red non the pic below also included the wire number and corresponding sheets.c

https://goo.gl/photos/TRnzhZUsXVoXoorS9