Generator/Shore Power Work, Battery Power Doesn't

[BrocNeal]

So I just bought this motorhome. It's a 1979 Dodge Tioga Class C. It's in great shape, but the past owner hooked up the battery wrong it appeared. To where one of the little 2 post circuit breakers would heat up indicating a direct short. I corrected that and still dont have any battery power in the motorhome. The battery rests at about 12.4, so it's not like new but from what I've read it's not considered dead. Could it still have screwed the battery up? The generator keeps it steady at about 12.4ish. I'm thinking the inverter or converter is fried? This is my first motorhome so I have no idea what I'm really looking at. I found the transfer switch I believe, it clicks off when the generator shuts off so I believe that's it. Where would I find the converter or inverter at and how do I know if they're bad? I found a little blue box looking thing that looks similar to a stereo amp under the hood and saw something similar at an rv store in the converter or inverter aisle. Other than that I dont really see anything that looks like what I'm looking for. Thank you guys.

[whemme]

BrocNeal wrote:

whemme wrote:
Be more descriptive, what do you mean by “black tune looking things”? Can’t tell by looking at your photo.

Its the black tube thing at the bottom of the picture. Its hooked to the silver thing in the corner and hooks to the thing on the right side of the picture. Its almost made of like ceramic. The guy told me its a "Ceramic resistor".

My opinion at this point is that the SCR component in this converter has most likely failed due to an earlier reversed polarity house battery hookup. That black ceramic high temperature resistor may also have been damaged. But since the owner is apparently not familiar with basic electronic component terms, his ability to repair this converter is in doubt. The best solution may be just to have the whole system replaced with a new unit by a qualified RV repair shop.

[bobndot]

time2roll wrote:
Boondocker $145

Well then in that case,
:B:B:C:C

[time2roll]

Boondocker $145

[bobndot]

time2roll wrote:
It is a resistor. Resistors get larger with higher watt ratings to dissipate the heat.

Either way just replace that converter already.

:B
For a couple of hundred $ you would be getting a multi stage converter .

[time2roll]

It is a resistor. Resistors get larger with higher watt ratings to dissipate the heat.

Either way just replace that converter already.

[BrocNeal]

whemme wrote:
Be more descriptive, what do you mean by “black tune looking things”? Can’t tell by looking at your photo.

Its the black tube thing at the bottom of the picture. Its hooked to the silver thing in the corner and hooks to the thing on the right side of the picture. Its almost made of like ceramic. The guy told me its a "Ceramic resistor".

[whemme]

Be more descriptive, what do you mean by “black tune looking things”? Can’t tell by looking at your photo.

[BrocNeal]

I got the converter part out. Where do I go from here? When I got the battery charge board from Progressive, they also sent me some of the black tube looking things because they occasionally go out also, do I try and replace that?

[BrocNeal]

whemme wrote:
Just wondering if the OP has successfully fixed his charger/convertor problem?

So unfortunately not. I haven't had time lately due to having our first kid, the motorhome has been put on the back burner for a minute. I'm working on getting a new battery for it. So when I took the old battery out, I decided to hook up shore power and see if I got 12 volts on any of the posts I was taking reads off of before. Because I figured if it was converting correctly that I should be able to see at those posts if it is or not. Is that a stupid test? It made sense in my head but don't know if it makes sense or not. But the results were 8 volts on one side and then shore power on the other side. Does that show anything or not? I was working on pulling out the converter since I'm pretty sure thats my issue but haven't gotten around to finishing it since I'm a lot more busy with other things now. Thats what my gut tells me the issue is but this thing has me thinking all sorts of different things so who knows!

[whemme]

Just wondering if the OP has successfully fixed his charger/convertor problem?

[whemme]

Click on the following link to see what the SCR(s) in your power center look like physically. This is probably not the actual SCR you may need but shows you what they look like. A thyrister is the same as a SCR. Typical SCR

The small terminal is the gate, the large terminal on the top is the anode and and body of the SCR is the cathode terminal.

[whemme]

BrocNeal,

Can you tell if there is just one SCR or two wired in parallel? If you can get one of the SCRs removed, look at the identification markings ( brand & P/N) on it. Should then be able to buy replacements.

But first get the voltage readings on the 3 terminals of one of the SCRs so that it can be determined if they are really bad.

[BrocNeal]

whemme wrote:
BrocNeal,

OK I guess I can assume the replacement charger board did not fix the problem. Your system may have only one SCR or maybe two SCRs wired in parallel. A SCR is a 3 terminal device, an input terminal (anode), an output terminal (cathode) and a gate terminal. When connected to shoreline power, measure the DC voltage to ground on all three SCR terminals. The output terminal should be the same as your house battery voltage, 12.48 volts per a previous measurement you made. The voltage at the input terminal should be I believe around 18 volts, the same as the output voltage from the transformer module you previously measured. The voltage on the gate terminal will tell the story. If it is more than 1.0 volt higher than the SCR’s output terminal, then that or both SCRs are toast.

No it didn't unfortunately. So im working on pulling the converter box out so I can check the SCR and everything. That's turned out to be quite the job but I'll get it. Once I get that out I'll be able to test it much easier than where its currently at. If the SCR is bad, is that something you can replace easily? Like just go buy a new one or do I have to find this exact same one or do I then need to find a replacement box as a hole? It looks intimidating not gonna lie.

[whemme]

BrocNeal,

OK I guess I can assume the replacement charger board did not fix the problem. Your system may have only one SCR or maybe two SCRs wired in parallel. A SCR is a 3 terminal device, an input terminal (anode), an output terminal (cathode) and a gate terminal. When connected to shoreline power, measure the DC voltage to ground on all three SCR terminals. The output terminal should be the same as your house battery voltage, 12.48 volts per a previous measurement you made. The voltage at the input terminal should be I believe around 18 volts, the same as the output voltage from the transformer module you previously measured. The voltage on the gate terminal will tell the story. If it is more than 1.0 volt higher than the SCR’s output terminal, then that or both SCRs are toast.