Onan generator intermittent starting issue

[Wantawinnie]

I can't find this problem in any search results.

I got my original 6500 watt Onan fired up yesterday. It runs fine once started and supplies power to the coach properly. This issue is an intermitent issue inside the control panel that has me confused.

What is happening is that I will get no power to the starting switch and a clicking can be heard in the top relay(?) next to the fuel pump. I started to troubleshoot and when I loosened the 3 wires all the way to the left on the board it seems to settle down the relay so that it would quick clicking. It would then turn over and provide ignition spark. If I unhook the 3 wires entirely the generator will turn over fine from both the switch on the unit and the remote switch on the dash but not fire because of no ignition spark. I cleaned up all the connections with no change. If I push the starting switch to "stop" the relay will stop clicking as well. I marked the areas with arrows that I am talking about.

What does that relay do? Is it a failsafe that is sensing a problem?

Another thing that has me worried is that the hour meter was hooked up to the center bolt on the regulator(currently unhooked wire with blue spade) will run as soon as the coach battery is hooked up. It turns whether the unit is running or not. The remote switch is also lit up all the time like it is running. Is this hooked to the right spot or is something wrong with the regulator?

Anybody have some advice, never messed with these things and it seems more complicated than it should be.

Thanks

[Lefty]

See if this link works:

https://skydrive.live.com/redir.aspx?cid=495123dd9dcdbb35&resid=495123DD9DCDBB35!254&parid=495123DD9DCDBB35!244&authkey=!AGW1ezXNCI0mTW4

I have an Onan Master Service manual in my SkyDrive that would cover your model genset. That should help you greatly.

[DaveVA78Chieftain]

Do you have a 6.5 NH (points based) or later 6.5 NHE model generator?  Different manuals for each version.  Also need the full number (i.e: 6.5NH3CR-16004P).

Dave

[Wantawinnie]

It is a 6.5 NH-3CR/6000C and the original one to the rig.

Thanks for the help guys.

[Wantawinnie]

I was just wondering if a dead or nearly dead coach battery could cause this issue or have damaged something? I unhooked the battery and it seemed to be taking charge but would not hold.

I replaced the coach battery with a automotive battery for testing and this issue is still there.

[DaveVA78Chieftain]

The "C" at the end of your number indicates "Spec C".
When using this manual make sure you understand that you want to use the portions for NH (Spec A-C) not NH (Spec D-F, K, or J).  There are pictures of the parts, schematics and troubleshooting procedures contained in it.  It covers several different generators in addition to NH so make sure you are using the portion of each section that applies to your unit.

http://www.cumminsonan.com/www/pdf/manuals/900-0196.pdf

I will look closer at schematic when I get home.

Dave

[DaveVA78Chieftain]

I believe your wiring diagram is very close to the one on either page 6-7 or 6-8.  Based on the picture on page 4-5, the relay that is chattering is the Stop relay (K2).  Read the circuit description on pages 3-2 and 3-3 (Figure 3-2).  K2 has to be kept energized in order to provide voltage to the coil and fuel pump.  However, you have to understand the chain of events as to how it stays energized.  Once you understand that, you can use the troubleshooting section starting on page 4-5.  My hunch is the K4 relay assembly circuitry may not be working properly.

Dave

[Wantawinnie]

Thanks for the manual and advice Dave,

I was looking through section 4 but didn't get to 6 yet. I am going to print this off and take it with me when I work on it again.

[Wantawinnie]

I just wanted to follow up on this. I haven't had the time or need for the generator but had a chance to mess with it today.

Problem was dead or weak batteries. I installed two new 6 volt golf cart batteries this morning and figured I would give it a try. When I hooked up the wires I was having issues with before there were no problems like before. Ran some fresh gas to the genny and it fired over after just a few cranks. Runs the A/C and everything just fine. The chattering must have been some type of relay that was affected by a weak battery. Even with a charger on the battery it was not right. Good deal!

[M & J]

     Thanks for the feedback on the solution.