12 volt tv issue

DON · February 04, 2017, 10:20 AM

Does anyone know what might cause blown fuse of tv problems when cranking on the generator. I have onan gen and 76 winnebago chieftain. I have had problems when plugged in to 12 volt adapter. If I don't unplug and then start generator, I blow fuse or worse have issues with tv. Could it be surge? If so, how can I prevent?

M & J · February 04, 2017, 11:07 AM

Sounds like your coach batteries cant maintain near 12v when cranking the genny. The adapter pulls more current when the voltage drops and exceeds the amp rating of the fuse.

Not a surge but a voltage drop while cranking. How old are your coach batts? All connections clean and bright? Dirty/loose connections can do the same thing. Take a volt meter and see what the 12v drops to when you crank the genny.

DON · February 04, 2017, 09:13 PM

Coach batteries are not very old. Will chk connections. Old 440 has trouble starting and getting fuel to carb. Maybe batteries drained because of past starting issues. Thanks.

DRMousseau · February 07, 2017, 12:23 AM

mmmm,... a bit more clarity here.

Quote from: DON on February 04, 2017, 10:20 AM
Does anyone know what might cause blown fuse of tv problems when cranking on the generator.

Does this happen when TV is on?? off?? either/both??? I'm thinkin' your speaking of the fuse INSIDE the TV itself, right?? If so, it sounds like it's doing it's job! Is this occurring when genny is cranking??? or when actually starting and firing up??? If you pulled plug wires so genny couldn't start, would fuse blow while cranking???

Quote from: DON on February 04, 2017, 10:20 AMI have onan gen and 76 winnebago chieftain. I have had problems when plugged in to 12 volt adapter. If I don't unplug and then start generator, I blow fuse or worse have issues with tv. Could it be surge? If so, how can I prevent?

"had problems" like in other problems too??? This IS a 12VDC TV that requires an adapter to plug into an 115V outlet (typical), right??? Or is this a 115VAC TV that requires a power supply adapter to plug into a 12VDC outlet (unusual)

If the latter, what 12V outlet are you plugged into,... house 12V outlet??? or cig lighter/chassis outlet???

Genny typically starts from chassis battery rather than house bank. That means your startup voltage drop of cranking battery is isolated from your house system. Your 12V lights and 12V house outlets won't dim when starting genny, but will instead BRIGHTEN as genny fires up and begins charging house bank. But your chassis battery WILL see a voltage drop, and dash lights/headlights will dim when starting genny, as will any maplights or cig lighter/outlets. That startup moment, MAY create a short startup surge and spike in the house AC system of which your converter/charger is a part of. Tough to do, but if you can monitor and measure your AC Voltage during this cranking, startup, and the moments following, you can be more certain that genny doesn't have various adjustment issues or is slightly excessive in it's output before settling down into running speed. Sounds like you have to wait a moment till genny settles into running speed before plugging in to ac outlet, right??? A surge strip MAY help that a bit,... and should a good one that can be depended on. But I'm still a bit confused here.

My 12VDC TV uses an AC-DC adapter. TV automatically goes off during any loss of power such as changing from shore power to genny or to inverter. I have to turn it on again after any change of power source, and this may be difference between us, as I've never had any issues.

DON · February 07, 2017, 09:48 AM

By "had" prior issues, I mean, at one point, I had to send tv back to factory to be repaired. Something happened inside tv. Since then, the 12 volt adapter fuse blew. I have a separate adapter, not the cigarette adapter in dash. I am wanting to use, of course, the 12 volt adapter so that I can watch tv without 110 volts of having to use the generator. However, for example, wanting to make coffee and needing to use coffee maker and having to crank genny, I would have to try to remember to unplug tv from 12 volt adapter so that the fuse inside the adapter or maybe even inside the tv also would not blow. This has happened when tv was on in the past. May happen when off also. Do not really know. Seems to happen when genny is cranking. Have not tried pulling wires. RV out of town. Do not get to use often. Hope I explained a little better. Not sure myself except that it seems to happen when plugged into 12v type adapter.

DRMousseau · February 07, 2017, 08:44 PM

Ok,... so I'm still assuming this is a 12V TV which is typical. I bought one for the convenience of 12V, but I generally run it thru the 115V AC adapter. Mostly because I have to keep constant AC power in some manner for my "household" fridge. So, I'm either on shore power, genny, or inverter!!! Never yet ran it on DC. And that's probably a good thing!!!

I'm a full-timer, and I occasionally see a DC "boost" of brightness in my 12V interior lighting,... even when on a constant shore line supply. All my lighting is 12V from battery/converter system except for one small AC table-lamp. So the sudden brightness is distinctive and quite prominent,... it's NOT momentary, but rather prolonged till it unnoticeably and gradually settles down to something typical(?).

I figured it was jus my converter/charger was cycling a charge or equalization to my battery bank. While it makes my lights a bit hotter (someday I'll get LEDs) and a slight boost to furnace motors, there's really been no issues of concern. And I am now thankful that my TV isn't running on DC!!!!

I think I'd measure and monitor that 12V system a bit,... jus as I probably should. My converter/charger boost mode is 14.6V, on a stable AC supply... and that's kinda close to max for 12V stuff, including my very bright lights!!! I wouldn't expect that start-up surge from the genny to affect that,... but my converter/charger is rather new and the output is well regulated. But it might be a critical issue with older or some other converter/chargers with 12V electronics on the line.

Anyone else have an noticeable issue like this???

DON · February 08, 2017, 10:33 AM

Thanks. I will have to do more checking with multimeter. Not a brainiac but will try to figure out. Looking into 12 volt surge suppressor just as a safeguard. May be weak battery as earlier post said.

DRMousseau · February 08, 2017, 10:00 PM

DEFINATLY related to weak battery,... that's why you started genny right?

But I think different than M&J noted. Genny starts on chassis battery, rather than low coach battery which may not be enough to start genny when needed. Since your TV's on the coach system, the draw on the chassis battery wouldn't affect it in any manner.

Since you started it to charge battery (or to make coffee), I'm thinkin' it's in the coach charging converter system, and might be related to initial AC surge from starting genny.

Seems I recall some "electronic" problems with mine, that were more related to "noise" though,... a technical term. Only occurred when furnace motor came on, while using an inverter for AC. Caused an electronic "touch controlled" AC table-lamp with fluorescent bulb to flicker badly and malfunction. Was quite annoying.

M & J · February 08, 2017, 10:13 PM

I said coach battery since thats how my Alegro is set up. Only the chassis is connected the engine battery. I do have a bridging switch that I can tie all the batteries together to jump start either but its momentary and not like the MOM switch the Winnie and others have.
I think there's no doubt you have a large voltage drop from which ever is cranking the genny.