I have a Generac 75D generator in my RV. This morning when leaving a park for an overnight stop it would start but shut down as soon as the start switch was released. Same result on multiple tries. Moved to our next location with no generator. Did some looking this afternoon and hope someone can answer a technical question. It appears it is shutting down doe to either a bad control board or a problem with the coolant over temp switch. If I remove the wire on terminal point 12 at the control board and jumper point 12 to 12 volts while cranking it will start and continue to run fine. If I check the voltage at point 12 while cranking I get 8 volts. Question – should the circuit board cause the generator to shut down with 8 volts applied? If 8 volts is to low the problem should be the over temperature switch as the over temperature switch had 12 volts going to it. The circuit board is about $300 but I probably can’t get one till Tuesday afternoon due to the weekend (we are scheduled to leave this location Tuesday AM). Easy to replace once I get it. May take as long to get an over temperature switch but it will take significant time to replace the switch (8 plus hours minimum) due to its location. The circuit board is Generac p/n 093642 and the over temperature switch is Generac p/n OD2791. Tempted to jumper 12 volts to terminal point 12 and let the parts catch up to me late next week. Any input will be appreciated.
Paul and Karla
Cinnamon & Pequeno - Spoiled Rotten Chihauhuas
2004 Rexhall Rexair DP3955
2013 Chevy Traverse
PandK wrote: I have a Generac 75D generator in my RV. This morning when leaving a park for an overnight stop it would start but shut down as soon as the start switch was released. Same result on multiple tries. Moved to our next location with no generator. Did some looking this afternoon and hope someone can answer a technical question. It appears it is shutting down doe to either a bad control board or a problem with the coolant over temp switch. If I remove the wire on terminal point 12 at the control board and jumper point 12 to 12 volts while cranking it will start and continue to run fine. If I check the voltage at point 12 while cranking I get 8 volts. Question – should the circuit board cause the generator to shut down with 8 volts applied? If 8 volts is to low the problem should be the over temperature switch as the over temperature switch had 12 volts going to it. The circuit board is about $300 but I probably can’t get one till Tuesday afternoon due to the weekend (we are scheduled to leave this location Tuesday AM). Easy to replace once I get it. May take as long to get an over temperature switch but it will take significant time to replace the switch (8 plus hours minimum) due to its location. The circuit board is Generac p/n 093642 and the over temperature switch is Generac p/n OD2791. Tempted to jumper 12 volts to terminal point 12 and let the parts catch up to me late next week. Any input will be appreciated.
Why not just eliminate your suspicions, such as the over temp. and see what that does. I've been running with the ground return disconnected from my oil over temp sw. for quite a while now. Still not sure if it's bad or the unit runs too hot and they do run hot. Don't know what I'd do about it running hot anyway, but so far so good. If I removed the wire going to pin 11 on mine, it would remove both the oil pressure and oil temp. from the circuit which shuts down the engine by going to ground. Pin 12 goes directly to chassis ground on my unit.
Having said that, it sounds like some sort of a locking relay on the board might be bad and assume that the only way you can shut it down with applying this said 12v is to remove same?
My Generator is a GN-480
Highline Q-55G
5.5KW
* This post was
edited 06/23/12 09:05pm by tropical36 *
"We are often so caught up in our destination that we forget to appreciate the journey."
1998 36ft. National Tropi-Cal Model 6350 on a 1997 Chevy P32
Chassis_7.4 Vortec Engine_4L80E Tranny_slide_tag axle.
I have an early 75D, only real problem causing it to shut off was an over sensitive coolant temp switch, disconnected it to keep it running. Exhaust flex pipe needed replacement, an electrical widgit required an additional relay installation radiator hoses have been a challenge to keep clamps tight, and starter motor required complete disassembly of gen set to replace, then there was the belt issues, other than that it's got 2000 hrs. and still makes power. I dunno if an Onan would be better, the 2.8 Microlite I got for the T/C doesn't make me happy. At least the Genereck is pretty quiet.
Appreciate the replies. I am going to order both parts and have then help at the next KOA. I know the oil switch is OK. Looks like I will be spending more time under the generator next week. The AC voltage "appears" to be building up properly. I did hold the start button for an extended amount of time to check that. Generator would run till I let go of the start button.
* This post was
edited 06/24/12 09:57am by PandK *
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