Briggs & Stratton Won't Crank-Help Please

Ga-Bill

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Hello. -New guy here. I can't crank my Murray Select 21HP B&S engine. I always thought I was pretty fair at trouble shooting B&S engines, but I'm stumped this time:frown: I've used this mower for years. Shut it down, now-nothing.
Here's what I've checked so far:
12.8V at battery.
good clean battery connection to ground.
good clean continuity to positive solenoid post.
12.8v at solenoid +post to gnd.
no voltage to other solenoid post (even when turning start switch).
no voltage to the starter - ever.
replaced the 4 wire solenoid & cleaned all connections there (including mounting to chassis).
no voltage on solenoid's orange wire (even when switching ignition).
checked seat,clutch/brake, & pto switches (all working fine).
ohm'd wires connecting seat,clutch/brake, & pto to start switch for continuity.
tried another known good start switch.
It's not the fuse as that was removed from the circut years ago.

I'm frustrated & stumped. What am I missing?
I appreciate you advice.
Ga-Bill
 

Fish

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Do you have voltage to the B terminal on the keyswitch? Do you have voltage to the S terminal on the keyswitch when you turn the key to the "crank" position?
 

Ga-Bill

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Thanks for the reply Fish...
My switch has 1 connector with 5 wires, & 1 black wire by itself. The electrical diagram calls them numbers 1 through 6.
What would the "B" and "S" connector be connected to? I'm out of time today, but I'll check voltages at the switch tomorrow afternoon.
Thanks
 

Fish

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Yeah, post the model numbers off of the tag under/behind the seat, so we know what you have.

On the back of the keyswitch should have letters stamped b,s,m,g,l etc. on each of the terminals
 

Ga-Bill

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Ok. Murray Select model # 465602x8D. My start switch doesn't have the letters on the switch or the connector either. The switch part number is 92377.
There's no voltage at any switch connections. It doesn't change when key is moved to any position.
There is always continuity to ground on terminals 2,3,4 & 6. Number 1 is connected to gnd only at "lights on" position. Number 5 is connected to gnd only at the "cranking" position.

Attached is the electrical diagram.
View attachment IMG.pdf

Was also wondering if the replacement solenoid is ok. But maybe we take one thing at a time...
Thanks All...
 

Fish

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Well, you should have voltage at the number 2 post on the keyswitch, unless the solenoid is hooked up wrong, or your fuse rigging has gone bad.

For the time, forget continuity, and just look for 12 volts or so. Can you snap a pic of this new solenoid?
 

Fish

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So follow the #2 terminal at the battery back, to the ammeter and fuse rigging, back to the solenoid, very simple path to check.

That should be on the big hot terminal on the solenoid, follow the little wire up to the keyswitch.
 

Ga-Bill

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Ok. Well, that is my problem. I had the red wire on the wrong solenoid post. Duh.
I moved it over to the hot post & cranks up fine now.
Feelin like a dummy,
Ga-Bill

Thank you for your help!!!
 

Fish

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great, glad you got it fixed!!!!!
 

Ga-Bill

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just goes to show - you never get too old to screw up.:laughing:
 
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