Converter issue (I think)

[George Participant NorCal Cheers: 374]

I am getting my 2004 Terra ready to sell.  Pulled it out of storage and noticed the 12v lights very week.  I checked water level in batteries – they were ok.  Plugged it into shore power and didn’t hear the converter fan go on.  Lights were still dim.  So I am assuming my converter died over winter.  Checked fuses/breakers, 120v power to the converter is good at the outlet (didn’t check output yet).  (120v power to all outlets too)

Here is the interesting part (and what I don’t understand) when I turn on the RV engine the A/C works (the fan also works).  Why would running the engine (with shore power plugged in) cause the AC to work?

I decided to check the converter output and noticed that the screw securing the hot (red) wire wasn’t tight.  I tightened it and now the AC works but lights still weak.  Are the lights run straight off the battery which are still weak?

I will check in the morning and see if the batteries (which are fairly new) charge up.

If you have any answers to the questions I asked I would appreciate understanding this better.

George

[Roger & Sue Fell Participant Edmonton, Alberta, & Summer Haven, Wetaskiwin County, Alberta Cheers: 2 488]

A lot of your control circuits use 12 volt to turn functions off and on, examples, fridge on propane uses 12 volt to run the gas valve, ignition and so on. AC thermostat the same. Hot water tank on propane the same. The truck provides a battery charge circuit when the truck is running.

[George Participant NorCal Cheers: 374]

Kind of obvious not that you mention it.  That is exactly what is happening as for a short time after I turn off the engine the fan still works — I assume because the batteries got a little bit of charge from the engine.  I am going to bench test the converter now.

Thanks a lot Roger, I couldn’t get my head around it.

 

Follow up:  Bench tested — dead.  New one on the way.

• This reply was modified 2 months ago by  George.

[Roger & Sue Fell Participant Edmonton, Alberta, & Summer Haven, Wetaskiwin County, Alberta Cheers: 2 488]

How many batteries are you running? If you have another 12 volt charger, this would be a good time to use it, the batteries will respond better if charged slowly, especially if they have been discharged for a while. Deeply discharged batteries can get quite hot and be damaged if rapidly charged. Something in the 6 – 10 amp range would be a good choice, at lot cheaper than having to replace batteries.

[George Participant NorCal Cheers: 374]

Thanks for the advice Roger.  I have two 12 volt.  I didn’t know about damaging deeply discharged batteries with rapid charging.  I guess I lucked out, I did recharge them with a trickle charge.  I charged each separately.  Then a potential buyer drove it for a half hour or so.  I get the new converter tomorrow.

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