klbastian7 Show full post »
BrianMartin
If all your wires are tight, including the negative wire on the engine mount near the back of the engine, I would pull the starter. If you jumped 12v to starter and it did nothing, it's most likely the starter motor.
Quote
klbastian7
Bench checked the starter/solenoidthis morning.  12V signal to the solenoid, and starter behaved as it should.  So now I'm looking upstream from there - I think there is a relay (SCR?) that could be the culprit. I'll see if I can bypass it and crank the starter.
Quote
Dick from Canada
Does the starter attemp to start the engine? The starter may run on the bench  but not develop  enough torque to turn the engine.  This is not uncommon with a faulty starter.  Where is the SCR?   If you are getting battery voltage to your starting relay and 12 volts to the starter motor the starting motor should attemp turn if all grounds are secure. An scr is a rectifier and can be either a bridge [4wires] or half wave[ 2 wires]. Do you have a drawing of your circuit? 
Quote
Dick from Canada
Looked at the drawing , the SCR is not a rectifier. Shown as as Starter Contact Relay. Sends 12  volts from the battery to the contactor . Can you give us an model no of the generator . Generac  is kind enough to put most of this info on their web sight.  
Quote
Dick from Canada
Searched  some of the 16KW generator drawings . They show the SCR relay in the main control panel. Shows a set of contacts that energize the starter contactor  . If nothing is happening at all when you attemp to start that could be the problem. Hopefully it is plugin relay or something simple like a loose wire. Use care if you go into the controller, utility power may be present if you have not pulled the fuses.
Quote
klbastian7
OK, here is the latest.  All is working fine now.  That's the good news.  The bad news is that I'm not sure what I did to fix it.  I verified that the starter was working properly when the starter contractor was given 12V.  So I looked at the SCR relay since that's where the 12V signal comes from.  I unplugged the wires from the relay and plugged them back in.  The generator then started just like normal.  The only thing I can figure is that there was a bad connection at the relay.  Anyway, I'm back in business.  Thanks for all your suggestions and thought on this issue.
Quote
Dick from Canada
Glad to read your problems have been solved .
Quote