12V lights flicker on generator

[joebedford]

I know there is another thread here called "Voltage fluctuation" and I suspect I'm getting some of the same effects. However, this is an Onan 5500 built-in that didn't used to do this.

Is there something that I can test to see what the problem is?

Is there something that wears in the Onan that could cause this? My unit only has about 200 hours.

It still does it with load (air conditioner) but all my electronic stuff works fine. Doesn't do it on shore power so it's not the converter (WFCO 100 amp). State of battery charge doesn't affect things.

[joebedford]

Checking for loose connections is a good idea. I hadn't thought of that.

[DrewE]

A random sideways thought: is there perhaps a loose ground or a loose connection at the converter or battery or somewhere, and the vibration from running the generator is making the wire dance around a bit? I guess a loose 120V connection at the generator or transfer switch etc. could have the same effect, too.

[joebedford]

wa8yxm: the 12v lights might even be brighter than normal but I could be imagining it. They flicker once or twice per second when the generator is on.

Mex: that sounds like a very bad thing. I was going to do some tests with my digital meter but maybe I shouldn't. My analog Avometer is at home 1500 miles from here.

[MEXICOWANDERER]

I haven't run my new-to-me WFCO through the paces as I am far from home. But input oscillations severe enough to affect switch mode output is SERIOUS. This is why I insist on pacjing a quality NEEDLE TYPE voltmeter. Mine is sitting 3' from me. That Onan could easily be oscillating 200+ volts peak-to-peak. DANGER WILL ROBINSON. That is enough to do serios damage. Sounds much like the voltage divider network in the genset took a powder. I'm afraid diagnostics here is beyond what the average owner would want to tackle. Professionally, the generator is taken offline. The regulator is disconnected. A small constant current is impressed via a power supply across the field after a 2KW dummy load has been connected. This isolates the problem to generator or regulator. With a resistance fixed test load the output had better be as steady as a rock.

[wa8yxm]

Normally the ONAN powers the converter, but if the voltage out from the ONAN drops enough, the converter (Depending on the model and type) may not be able to output charge (or float) voltage and thus the lights will dim as the system switches to battery power,, then brighten when the system voltage again rises.

[enblethen]

Did you check the voltages coming out of genset and 12 volts coming out of the converter?

[joebedford]

I have mostly halogen lights. They flicker quickly for minutes at a time.

Why would you think it's the WFCO when it doesn't do this on shore power?

[Matt_Colie]

Joe,

First, describe the the flicker...
ie: Short blinks that happen a lot -
- - Lights go dim for a few moments and then come back bright -

Most RVs do the interior lights with 12V. If you have LED lighting that is being strange, blame the WFCO. They are pretty much junk out of the box.

Probably most of your "electronic stuff" is running off the AC and that would let the Onan off the hook.

Matt

[enblethen]

Put a volt meter on the 120 volt output. It can be plugged into a receptacle.
It could be a failing voltage regulator.
You could do it on a 12 volt DC circuit or at the battery as the converter output would rise and fall as 120 volt AC input changes.