Welcome to the DoItYourself Forums!

To post questions, help other DIYers and reduce advertising (like the one on your left), join our DIY community. It's free!

ignition/solenoid troubles 15 hp briggs


strobel19606's Avatar
Member

Join Date: Apr 2007
Posts: 30

04-27-07, 02:13 PM   #1  
ignition/solenoid troubles 15 hp briggs

i was given a 15 hp craftsman i/c gold twin briggs 15hp 402707. the only way i can start it is by placing a screwdriver between the solenoid posts. it starts right up. when i turn the key, nothing...not even a click. im not sure how to check the battery b/c i have to charge it before starting. i dont think the alternator is working but i want to fix the cranking problem first. i have 16 volts at the battery and 16 volts at the solenoid (while charging) but nothing when i turn the key. i checked the 3 safety switches and they all seem ok. any help will be appreciated. thanks!

 
Sponsored Links
Azis's Avatar
Visiting Guest

Posts: n/a

04-27-07, 02:28 PM   #2  
Azis
On the solenoid there should be at least one small terminal, perhaps two. Find the one from the key switch, if only one then that will be it. You can use a jumper lead to run from battery positive, either from the battery or the battery side of the solenoid lug, and apply 12v to the small terminal. If the starter engages then the solenoid is good and problem lies with the key switch or possibly its ground. If this does not engage the solenoid then the solenoid is most likely bad.
If the battery will not hold a charge overnight, (without cranking on it after charging) then you should have it tested and prolly replaced.

 
strobel19606's Avatar
Member

Join Date: Apr 2007
Posts: 30

04-27-07, 03:09 PM   #3  
will click but wont crank

right now i have 12.6 volts at the battery. when i jump from the battery pos. to the small post, i hear a click, but it wont crank. when i jump to the larger post, it starts right up.

 
puey61's Avatar
Member

Join Date: Apr 2004
Posts: 3,224
NY

04-27-07, 04:36 PM   #4  
It will not crank over without the clutch/brake locked. Since you hear a click at the solenoid it is likely good and since you say the safety switches are good then it is safe to assume the key switch is bad and in need of replacing.

 
strobel19606's Avatar
Member

Join Date: Apr 2007
Posts: 30

04-27-07, 04:43 PM   #5  
thanks guys!

i will buy a new key switch asap. i also noticed a ring terminal with one black wire and one blue wire that is not attached to anything....do you know what that might be? there is also a red wire with a white stripe that is not attached to anything......about the key switch..when i jump the 2,4,5 terminals together (start mode) i dont hear anything. not even a click. do you think the key switch still might be bad?

 
Azis's Avatar
Visiting Guest

Posts: n/a

04-27-07, 04:53 PM   #6  
Azis
Is the ring terminal with black and blue wire near the solenoid? Is there another small terminal on the solenoid?
If you happen to cross 12v to the coil while jumping the terminals, you can esily fry the coil.
It also sounds like your battery may not be holding a charge when a load is placed on it.

 
strobel19606's Avatar
Member

Join Date: Apr 2007
Posts: 30

04-27-07, 04:58 PM   #7  
terminal

the unconnected ring terminal is next to the solenoid terminal. i dont have much confidence in my battery. how can i test it other that a volt meter? thanks for your help!!!!

 
strobel19606's Avatar
Member

Join Date: Apr 2007
Posts: 30

04-27-07, 05:01 PM   #8  
solenoid

there is no other small post on the solenoid terminal.

 
Azis's Avatar
Visiting Guest

Posts: n/a

04-27-07, 05:08 PM   #9  
Azis
I need the rest of your engine numbers to access a drawing. That terminal may be a ground for the solenoid.
Any parts store will usually load test your battery free of charge.

 
strobel19606's Avatar
Member

Join Date: Apr 2007
Posts: 30

04-27-07, 05:21 PM   #10  
more codes

it is a 15 hp twin b & s.
402707.....type 1242 01 code 9405145a

how can i find troubleshooting guides or wiring diagrams for this mower?
can you tell how old this is from the codes?

 
Azis's Avatar
Visiting Guest

Posts: n/a

04-27-07, 09:33 PM   #11  
Azis
http://www.briggsandstratton.com/display/router.asp?DocID=64103

 
cheese's Avatar
Forum Topic Moderator

Join Date: Jul 2001
Posts: 16,564
GA

04-28-07, 01:11 AM   #12  
What is the voltage at the small terminal on the solenoid while trying to start it?


"Who is John Galt?" - Ayn Rand (Atlas Shrugged)

God bless!

 
strobel19606's Avatar
Member

Join Date: Apr 2007
Posts: 30

05-03-07, 03:15 PM   #13  
wiring diagram

i got the wiring diagram/assembly emailed to me. in the start mode, one of the terminals (blue wire) is supposed to go to an hour meter and then to ground. when i traced it, the fork terminal at the end of the single blue wire is not attached to anything. i dont have an hour meter. (unless it is hidden). do you think this might be the problem? how hard would it be to re-wire the whole thing? does it matter which red wire goes to which post at the solenoid? should i flip-flop them? do both sides of the solenoid need to be screwed down? (right now i just have one of them screwed down. thanks for your help!!

 
cheese's Avatar
Forum Topic Moderator

Join Date: Jul 2001
Posts: 16,564
GA

05-04-07, 12:44 AM   #14  
This is a really simple problem you have. Put it all together like it should be, install a good battery, and measure the voltage at the small trigger wire on the solenoid when trying to start it. With the info from this test, we can figure out what is wrong. You can't test it with some of the wires loose or disconnected. No need to think about re-wiring the mower. Just need to perform a test or two to determine the cause of the problem, not guess at it.


"Who is John Galt?" - Ayn Rand (Atlas Shrugged)

God bless!

 
strobel19606's Avatar
Member

Join Date: Apr 2007
Posts: 30

05-04-07, 03:37 PM   #15  
there is no voltage at the small yellow wire before, during, or after cranking. it is only reading ohms. 10.3 when off. 11.6 when i turn the key. maybe i should just leave it alone and keep jumping the starter. today i must have messed up the blade engage switch because when i start the blades, the motor shuts off. i had to take the switch out and tape it closed........maybe i should just leave it alone before i have NO mower. i have been studying the wiring diagram for days. i dont want to mess this thing up any more than it already is. but i do appreciate all of your help!!

 
cheese's Avatar
Forum Topic Moderator

Join Date: Jul 2001
Posts: 16,564
GA

05-04-07, 10:50 PM   #16  
The engine shutting off when the blades are engaged is probably the seat switch's fault. I'm not sure what you mean by reading ohms on the trigger wire. Where is the resistance? Between the solenoid wire and what? The keyswitch? Check the fuse. I have a feeling with all that's been done so far, you may have blown a fuse, causing the no-voltage at the solenoid.


"Who is John Galt?" - Ayn Rand (Atlas Shrugged)

God bless!

 
strobel19606's Avatar
Member

Join Date: Apr 2007
Posts: 30

05-05-07, 04:30 AM   #17  
the fuse is new. but there is a red wire with a white stripe that isnt connected to anything. im not sure about the ohms....i guess there is no voltage at the small solenoid post no matter what i do. i noticed on the wiring diagram that the red/white wire runs from the fuse to the ammeter, but the ammeter seems to be wired already (although it doesnt read anything) this red/white wire is down by the engage/disengage switch next to the solenoid. should i take all the tape off the wires and follow them one by one? should i get a new key switch? how much do they run?

 
Azis's Avatar
Visiting Guest

Posts: n/a

05-05-07, 06:11 AM   #18  
Azis
I would suggest reading the instructions for your meter, or put it away before (if not already) you damage it.
Use a jumper lead, (or a lead removed from your VOM) and connect one end to battery +. Touch the other end to the small terminal on the solenoid. If the solenoid engages, clicks or turns the starter, then most likely the problem is the key switch(wiring and safety switches also possible). If you get nothing, then the solenoid is likely the problem.
What switch did you tape closed? If you did it to the PTO switch, then does the engine die when you release the clutch? As cheese mentioned it sounds like the seat switch is at fault.
You should have no need to remove tape and wires from the harness. When using an ohm meter, power should be disconnected and verified on the part of the circuit or component being checked.

 
Azis's Avatar
Visiting Guest

Posts: n/a

05-05-07, 07:40 AM   #19  
Azis
[quote author=cheese link=topic=1249.msg9582#msg9582]measure the voltage at the small trigger wire on the solenoid when trying to start it. With the info from this test, we can figure out what is wrong.[/quote]

cheese would you mind sharing just what you are looking for with this test? What one might see and solution for each case?

TIA

 
strobel19606's Avatar
Member

Join Date: Apr 2007
Posts: 30

05-05-07, 11:26 AM   #20  
when i jump from the battery to the small post. yes i do hear a click. but the starter doesnt turn. just a small click. no voltage to the small post when i turn the key. i taped off the blade engage switch last night and it runs fine. my seat switch is also wired together.......not a very safe mower at all.

 
cheese's Avatar
Forum Topic Moderator

Join Date: Jul 2001
Posts: 16,564
GA

05-05-07, 11:25 PM   #21  
Ok, if the battery on this mower is indeed good, and the connections are clean and tight, then your solenoid is bad.


Azis, I was trying to see if the mower was sending power to the trigger terminal of the solenoid. If it was, and the solenoid wasn't responding, then we'd know the solenoid was bad. If it wasn't, then I would have gone to the keyswitch to see if it was sending from there. If not, bad switch. If so, then traced to the safety switches.

Now we know voltage is getting to the solenoid when he jumps it with a wire like you mentioned, and the solenoid is only responding with a click, but no action of the starter (which we know works). So if all the connections are good and the battery is good, the solenoid is bad. The bad part is that the solenoid is probably not the only problem now with all the other stuff that's been done.


"Who is John Galt?" - Ayn Rand (Atlas Shrugged)

God bless!

 
strobel19606's Avatar
Member

Join Date: Apr 2007
Posts: 30

05-06-07, 06:34 AM   #22  
so even if the solenoid clicks, it could still be bad? this mower was given to me. i dont know the history of it. i assumed since it didnt start with the key, the previous owners may have messed with the wiring. maybe i am digging too deep and trying too hard. maybe it is something simple and i should stop messing with it. all the connections are there. nothing appears to be "rigged". i do have knowledge about how things work and i love working on engines. i will get a new battery, key switch, and solenoid for it. this thing runs great and i plan on keeping it for a long time. i will let you know if the previous combination works. thanks to all for helping me!


mark

 
Azis's Avatar
Visiting Guest

Posts: n/a

05-06-07, 07:49 AM   #23  
Azis
Thx cheese for the explanation. Sounds like the same checks basically however if one knows how to safely use a meter, your way sounds much safer. I was thinkin/hopin maybe you had some magic test for the safety circuit, IE:the elusive "shunt" LOL
I will tuck that one away in perm memory heheh

strobel19606, when you apply 12v to the small terminal you are basically doing the same thing the key switch does. The click you hear is from the magnets in the solenoid being energized and trying to latch in the switch, which shorts out the two big lugs on the solenoid, supplying 12v to your starter. Since when you do this, the starter does not engage, and assuming connections are good, then the switch/relay part of the solenoid is not latching.
It sounds at this point like all is still able to be restored. You would save yourself future headaches by accomplishing that.

 
cheese's Avatar
Forum Topic Moderator

Join Date: Jul 2001
Posts: 16,564
GA

05-07-07, 12:41 AM   #24  
You talking about the shunt in the seat switch on some mowers? The safety system is pretty easy to diagnose with a meter too. You'd just find the terminal on the back of the keyswitch marked "S", and start there, working your way through the safety switches to the solenoid, checking for power when the key is turned to start with all safety switches engaged for starting. The switch where you lose the power is the bad one.


"Who is John Galt?" - Ayn Rand (Atlas Shrugged)

God bless!

 
Azis's Avatar
Visiting Guest

Posts: n/a

05-07-07, 07:06 AM   #25  
Azis
Ya cheese thats what I was talking about. I guess the seat switch is the only one I have found go bad. It seems to me that simply attempting to jump this switch will render it defective...? yet the switch will still ohm out. Just a pet peeve I guess as I like to be able to show a part bad before spending .50 or 50.00

 
cheese's Avatar
Forum Topic Moderator

Join Date: Jul 2001
Posts: 16,564
GA

05-07-07, 09:24 PM   #26  
If the seat switch ohms out ok, then it's good. The shunt or whatever they call it is actually part of the connector. Look closely (it's pretty much un-noticeable) on a craftsman mower at the connector on the seat switch, with the switch unplugged. Right between the 2 slots for the spade terminals is a small rectangular plastic piece the same color as the rest of the connector. Take a small screwdriver and push on it. You'll see that it pushes into the connector, and is spring loaded so that it returns to it's position once you release it. This is making a short. When you push in on it, it releases opens the connection, but when you release it, it shorts out the connector, as if the seat switch was bad. (making it act as if there is no-one on the seat). Now, look at the seat switch in the same place. There is a little bump that extends out between the 2 connectors. This little bump pushes in on the plunger on the connector. This opens that "shunt" in the connector so that the seat switch can control the circuit instead of it being continually shorted. Now that bump is very small, so it doesn't push in the plunger very far. If the connector gets just slightly loose, the plunger isn't activated anymore. So, the mower acts like the seat switch is bad, but you remove it and check it and it will ohm out ok. You can replace it with a new one with a new un-worn "catch" for the connector, and the connector is tight again, opening the "shunt" again. This would make you think the old switch was bad even though it ohms out ok. The fact is, the old switch was ok, just a bit worn where the connector clip snaps onto it, and allowed the connector to back off of it just a hair. Usually you can just put a cable tie around the switch and connector to hold them tight together again, and everything is fine once again.

Wow, I didn't mean to write a book...sorry so long.


"Who is John Galt?" - Ayn Rand (Atlas Shrugged)

God bless!

 
Azis's Avatar
Visiting Guest

Posts: n/a

05-07-07, 09:45 PM   #27  
Azis
Well I appreciate the detailed explanation. I have intended to tear into one of them switches, just so I can see what there is. At least I know its worth a look at sometime if not next time its a problem.
That also explains how some of these switches get "worn" quickly

 
cheese's Avatar
Forum Topic Moderator

Join Date: Jul 2001
Posts: 16,564
GA

05-07-07, 11:19 PM   #28  
I also meant to put emphasis on the fact that the shunt is on the connector on the tractor harness, not on the switch.


"Who is John Galt?" - Ayn Rand (Atlas Shrugged)

God bless!

 
Azis's Avatar
Visiting Guest

Posts: n/a

05-08-07, 05:50 AM   #29  
Azis
heheheh ok thx, I don't think I would have started there.

 
princess1090's Avatar
Member

Join Date: May 2007
Posts: 1

05-24-07, 12:42 PM   #30  
i need help

Can anyone tell me where i can find my safety neutral switch on a 1990 Thunderbird. It would be very helpful

 
Search this Thread