Generator Won't Start

[Cwray]

I am currently on a trip for the weekend and this morning when I tried to turn on the Genny--it wouldn't crank.

Following the advice on this thread, I took a voltmeter and tested for power in the front of Genny. I am not an electrician, and am horrible with the voltmeter and understanding what symbols mean what and how to do it.

But I set the voltmeter to DC (pretty sure, as it had the same symbol on the dial as under the red post on the generator), touched the red probe to the red post, and then took the black probe and placed it against the braided wire & screw next to the ground label. That read 12.75 volts--which according to the troubleshooting guide is what the generator needs to crank.

But still nada.

In one of the troubleshooting guides, I found a quote "if it does not crank, check the control fuse (5A Slo Blo, except models with electronic governor 10A)."

I have an Onan 5500 gas generator on a Hurricane 34j.

I'm now on a quest to figure out where that may be and if my model has an electronic governor or not--while the wife is driving the rig and we're both hoping the fridge doesn't get too warm and the stuff in the freezer doesn't thaw in the last 4 hours of driving we've done (and another 90 yet to do).

Life's an adventure, right?

[16ACE27]

That's good voltage to the generator, but, WHY do you think you need the generator to run the fridge/freezer?

If it's a propane/120 VAC fridge it should be running on propane.
If it's a residential fridge it should be running on the inverter.

[Cwray]

We have a residential fridge…snacks head. I forgot that we could turn on the inverter while we were driving to power it. The inverter automatically turns on when the generator runs, and due to frustration and short-sightedness I forgot that it would be ok to manually turn. On the inverter while we were driving. The alternator would keep our house batteries charging during the drive.

Well, we made it, and in case anyone is wondering, if you leave your fridge/freezer closed— for a 7 hour drive your residential fridge will be ok and your freezer will (mostly) be ok as well. Our freezer was mostly empty, so nothing to help keep the cold other than some popsicles and a container half filled with ice. The ice got a bit fused together. But that was it.

I think the next step for me troubleshooting the generator is figuring out what the solinoid and starter is, taking off some screws and plastic casing, and jumping/bypassing the solinoid to get that 12.7volts directly into the starter. Then I can see if it cranks or not. I’m thinking that I need a fairly thick wire for that given the thickness of the cable coming from the batteries. Or would a simple 10/12 gauge wire suffice between the lockdown nut on the front of the solinoid and the starter?

[dkoldman]

Originally Posted by Cwray

when I tried to turn on the Genny--it wouldn't crank.


But still nada.

You confirmed you have power, but besides the obvious that the generator did not crank ( start), can you clarify what happened, what sounds, no sounds, dead etc?

Are you starting inside with manual switch?
Are you starting outside with push button switch?
Are you starting with Auto on from AGS etc.?


I am assuming you get ZERO sounds when trying to start meaning it does not try to turnover. If that's the case you are not getting power to the starter from the switch.

If you can find the starter post, you could get a jumper wire and bypass the switch to confirm it starts and wiring is corroded or switch is bad.

FWIW, on absorption fridges, it cools just the opposite. My Freezer is down to 6 degrees in 3 hours or so, the Fridge may take twice as long to get into 40s or 50s based on outside temp and what is inside. In fact on a trip we always put the drinks we intend to drink on initial journey in the Freezer because we may have only turned our Fridge on a hour or two before leaving. Also when driving not only is our Inverter always manually turned on (it does not come on automatically) our AGS is set to AUTO ON so the genny turns itself on & off.

[OldWEB]

Originally Posted by Cwray

We have a residential fridge…snacks head. I forgot that we could turn on the inverter while we were driving to power it. The inverter automatically turns on when the generator runs, and due to frustration and short-sightedness I forgot that it would be ok to manually turn. On the inverter while we were driving. The alternator would keep our house batteries charging during the drive.

The inverter is typically there to provide AC power when none is available (no SP or generator) if the batteries are good. If the inverter is also a charger, with AC provided it will charge the connected inverter batteries.
An inverter may provide AC while there is SP or generator AC, for protected power to delicate electronics.
An inverter may have AC "pass-thru" where the inverter remains "on" but the SP or generator power will "bypass" the inverter and supply the inverter loads.
It all depends on the type of, the wiring of and the settings of said inverter.

[Cwray]

Appreciate the replies guys. We were out in a poor cell / no internet spot for the weekend. (And it was great!)

Yeah, the generator is making -0- noise when I try to start it. Tried the main control panel, the switch by the steering wheel, and by pulling off the Onan front cover and pushing the button. In doing that, I also verified the priming light never can light either.

Chassis and house batteries are all nice and topped off.

Thanks for the suggestion on trying to get power directly to the starter post. I’m going to hit the internet for some diagrams/manuals to assist me and see.

[dkoldman]

Originally Posted by Cwray

Appreciate the replies guys. We were out in a poor cell / no internet spot for the weekend. (And it was great!)

Yeah, the generator is making -0- noise when I try to start it. Tried the main control panel, the switch by the steering wheel, and by pulling off the Onan front cover and pushing the button. In doing that, I also verified the priming light never can light either.

Chassis and house batteries are all nice and topped off.

Thanks for the suggestion on trying to get power directly to the starter post. I’m going to hit the internet for some diagrams/manuals to assist me and see.

Here is what starter look like. It could be your issue.

https://www.amazon.com/Cummins-19123...16011188&psc=1

Simple to see the positive post ( red) take some nice heavy gauge wire and connect to your input 12v source that you confirmed is 12.75vdc and run straight to this post. BE SURE Disconnect switches are off until you are ready to test. You don't need it to actually start but you want to here it go yank yank trying to turnover.

If it works you have bad switch or corroded wire from switch to starter.

If it stays dead, no sound, you have bad starter. Sometimes you can tap it lightly and it works, but even if it did, I would get new starter.

[javelin]

I don’t know the specifics of the 5500 gen, but if the remote and local “start” switch lamps don’t light when you try to start the gen, then you may have an issue with the control module itself at the gen since I “think” once the control module gets a ground signal from either remote or local start switch, it then turns on the starter solenoid to operate the gen crank motor. I am “assuming” this is how your gen functions. You used a voltmeter to confirm your “good” +12.7 voltage at the gen solenoid (to ground) it seems, from your previous description. I would also physically check and make sure that any generator control cabling plugs/wiring to/from the gen control board are clean and solid, especially ground and battery connections. The worst scenario would be a failed gen control board.....hope it’s just a bad / loose connection/plug.



The Cummins/Onan gen installation manual should provide you with the electrical install details and might include a basic schematic. I am not sure where your gen control board is physically located but usually in or around the generator I would expect.

[Cwray]

Well....

I went out last night to "get real" with this thing. I had my iPad out with a ton of YouTube videos, all the manuals from Onan, a flashlight and a beer and I was going to figure out what to do and see how much of a pain it will be to drop the generator, to pull it out, and work on it.

And it fired right up.

I didn't touch any wires, both the house and chassis batteries registered the same voltage as it did on Friday, as well as the whole weekend. I compared them with both being plugged in to 50Amp shore, as well as having that disconnected for a while.

All three methods of starting worked great. No error codes, and it primes right up and jumps on like a champ.

:ugh: Now what?

[dkoldman]

Originally Posted by Cwray

Well....

I went out last night to "get real" with this thing. I had my iPad out with a ton of YouTube videos, all the manuals from Onan, a flashlight and a beer and I was going to figure out what to do and see how much of a pain it will be to drop the generator, to pull it out, and work on it.

And it fired right up.

I didn't touch any wires, both the house and chassis batteries registered the same voltage as it did on Friday, as well as the whole weekend. I compared them with both being plugged in to 50Amp shore, as well as having that disconnected for a while.

All three methods of starting worked great. No error codes, and it primes right up and jumps on like a champ.

:ugh: Now what?

Fire up your AC's
Turn on all power that is needed
Pop some

Set your AGS to Auto Start. Let it turn itself on/off automatically when coach is cool or set for quiet time to shut off at a set time and to end the quiet time 1 hour later, just to let it do it's thing.

We now know it is starter or related to wiring.

[16ACE27]

Originally Posted by Cwray

Well....

I went out last night to "get real" with this thing. I had my iPad out with a ton of YouTube videos, all the manuals from Onan, a flashlight and a beer and I was going to figure out what to do and see how much of a pain it will be to drop the generator, to pull it out, and work on it.

And it fired right up.

I didn't touch any wires, both the house and chassis batteries registered the same voltage as it did on Friday, as well as the whole weekend. I compared them with both being plugged in to 50Amp shore, as well as having that disconnected for a while.

All three methods of starting worked great. No error codes, and it primes right up and jumps on like a champ.

:ugh: Now what?

Now you know you have an intermittent problem.

Check the main starting power connections to the generator (+ to the solenoid, ground to the frame - both ends).
Check the main control plug for corrosion.

Standby with a plan for the next time it rears its ugly head.

[Cwray]

Thanks guys. I’ll keep that in mind and do some more poking.

[Jimbo56]

Originally Posted by Cwray

Thanks guys. I’ll keep that in mind and do some more poking.

Start at beginning. Have you checked the oil level? Did you have more than a 1/4 tank of gas?

[holtcg]

Originally Posted by Jimbo56

Start at beginning. Have you checked the oil level? Did you have more than a 1/4 tank of gas?

In my experience, it would still turn over. The 1/4 fuel requirement is achieved very simply by placing the intake tube 1/4 of the way up the tank. Lack of fuel would turn over but not start.

[thenne1713]

The FUSE should be right NEXT TO the START switch, the BATTERY CABLE where you tested on GEN most likely goes to one side of the contacts on the SOLENOID. If you pull ELECTRIC box COVER, (with START switch) you will likely see full solenoid and terminals? My old Onan Emerald Plus has two fuses, one a glass fuse on panel cover, feeding circuit board, other a flat blade fuse, mounted by pump, feeds pump. GOOD LUCK.

[Jimbo56]

Originally Posted by holtcg

In my experience, it would still turn over. The 1/4 fuel requirement is achieved very simply by placing the intake tube 1/4 of the way up the tank. Lack of fuel would turn over but not start.

Mine was low on oil when new. Would not start due to low oil after it ran for a while. If low oil it won’t turn over due to safety switch.