Newbie ~ electrical problem

Thanks for getting back to us so quickly. That doc is not the one we are using although it is similar. Ours has Troubleshooting Guide upper left and under that is Series 7100 and Model 7155. The image displayed does not match our converter exactly, but it is much closer than the PDF you provided the link to.

We just checked and the converter/charger is made by Atwood Mobile Products. There is nothing online but called them. They don't sell the product anymore but happened to get an old hand on the phone and he explained it all. The fact that we get a reading with the 30A fuses pulled and don't when they're installed tells him the transfer switch is probably bad and we need a new converter (no repair). Plus, he gave me a little extra info. He says Parallax makes a good converter but to spend the most you can afford. He says all switching topology creates DC variation and is called "output ripple" (which I'm sure you are familiar with) and that the better converters have lower ripple effect. Since his product has the converter separate from the breaker box and fuses, etc., we can just buy a good 55A converter (if it will fit) and we'll be fine.

I hope that's it. If it fixes all our problems, we'll come back and post here. If you can think of anything to add, please feel free to do so. You've been a big help and we thank you again.

Is this the diagnostic flow chart you were using ?
If so. and you read the directions carefully, it will say to disconnect the wires from the output terminals for measuring the converter's voltage output. Did you disconnect the wires?
The .1 difference in low side voltage may be that the converters output is lower due to the wires being connected.

As was suggested, if your battery is bad, replace it with a new one and typical diagnostic procedures will quickly turn up a bad converter. You can use a conventional battery charger if the converter is not working but you shouldn't move the trailer without a good battery connected. The battery is power for the emergency braking system.

What seems unexplained is that you have 13.1 volts on the converter's outputs but no function of any 12V devices. This would indicate that there is a loose connection or you have a fuse or circuit breaker blown/tripped.

First, on line 2. of our Status note, it should begin "With no battery CONNECTED", not disconnected. Sorry about that.

krobbe: We're following the troubleshooting process from a flowchart from PPS Parallax Power Supply L.L.C. - Troubleshooting Guide we printed off the internet. I'd attach it for your review but can't see how to do that. It calls the two 30A fuses "polarity" fuses and the six 15A fuses "DC load" fuses. It references VC and VDC and as far as I can determine, those terms are pretty much interchangeable. The doc says first to check for blown polarity fuses. Did that, they're ok. Next we're directed to disconnect shore power, remove the polarity fuses, reconnect shore power, and "check for DC output between the blue wire and the "Neg-" negative terminal on the fuse block". When we do that, we get 13.1 as a result. The doc says the result should be between 13.2 and 14.2 VDC. We're not sure whether such a small difference between our result and the desired result is indicative of a bad converter. Regardless, after the question "Is the voltage correct?" is asked, we are directed to "See Note 2" which says "If the unit has correct DC voltage with "polarity" fuses removed, but does not when "polarity" fuses are in place the converter may be in over current mode." We measured with polarity fuses in place and the result reads zero. So, in order to exclude "over current mode" as a possibility, we then pulled each of the DC fuses and measured after pulling each. As long as the polarity fuses are in place, the results of the measurements are always zero. Plus, as sort of an aside, we pulled the polarity fuses while all DC fuses were uninstalled, and the reading was 5, not 13.1. Re-installing all the DC fuses (but not the polarity fuses) brings us back to the 13.1 reading. You say there would be no benefit in such a measurement, and we don't understand why they say it's important, but they do.

westend: No battery connected during all testing (haven't bought a new one yet - will tomorrow). The only measurement we are directed to perform by the troubleshooting doc is the blue wire-to-Neg- terminal mentioned above. Yes, all circuit breakers are untripped, and no, none of the 12v devices are working.

Mandalay Parr: Will pick up new battery tomorrow.

Thank you all for your input. If you can think of anything else for us to try before we get the new battery, we'll do it. By the way, no chance of the new battery getting damaged by hooking it up with whatever converter problem(s) we might have is there?

Do nothing else until you get a new battery.

Jerry

Did you have a battery connected when you were doing this voltage measuring? If so, your measurements of 13.1 were probably from the power in the battery.

AFAIK, removing the polarity fuses from the converter, disables any output from the converter. Where are you measuring for voltage at the output of the converter?

5., I have no idea unless the bad cells in your battery ceased to pass voltage at that time.

You do not have to worry about or try to measure any "over current" conditions at this time. For some reason your converter is not working and that should be the focus of your troubleshooting, Since you have adequate AC voltage coming into the trailer and all your circuit breakers are on (they are all untripped aren't they?), it would seem that the converter has failed. You can confirm this by connecting to shore power and place one meter lead on one battery terminal and the other lead on the other terminal. If the converter is good, it should measure 13.5 V or more. The only other thing to check is the fuse or circuit breaker close to the tongue of the trailer it may be in a plastic box or attached under the frame of the trailer. If that circuit breaker near the tongue is tripped, the battery can't deliver any power to the distribution panel. If you were measuring voltage at the panel, disregard this as it is working.

Are any of your 12V devices working (lights, water pump, stove fan)?

I'm not understanding your troubleshooting method. It seems as if you are interchangeably using terms like polarity fuses, dc fuses, voltage, current, etc. In comment 2, are you reading voltage between a blue wire post that is 12vdc and a red wire post that is 120vac? There would be no benefit in doing this. If you suspect that the DC output from the converter to the battery is a problem, you should read something like 13.6 volts DC.

Status:

1. Battery disconnected, removed, and tested at AutoZone. Battery fully charged but bad.

2. With no battery disconnected, polarity fuses removed from converter, shore power on, instrument testing leads on blue wire post and red wire post, reading measures 13.1.

3. Shore power off, polarity fuses installed, shore power on, reading
measures 0.00. (Is this what is described as an "over current condition"?)

4. To test for "over current condition", supposedly can disconnect shore power negative from converter box OR disconnect each DC fuse and re-measure (with polarity fuses still installed).
Easier to disconnect each DC fuse and re-measure. Did so and re-measured after dis-connect of each fuse. Result always stayed at 0.00.

5. When all DC fuses removed - and measurement still at 0.00 -
disconnected shore power, removed polarity fuses, re-connected shore power and re-measured. Result = 5 (why not 12?)

6. Shore power disconnected, re-installed all DC fuses, re-measured,
result again 13.1.


By the way, measured the current at the shore power connecter on the
outside of the RV, and got 122. Could never find a way to measure inside the converter box to show 122 coming in.

Based on above, any idea whether converter is bad?

Hello again ~ update...

The battery was not connected backwards and it had water. It had a Walmart sticker so we suspect it may not be the original 2008 battery. Nevertheless, we took it to Auto Zone and they diagnosed that it had a full charge but it was BAD. We have not bought a new battery yet. Any type you recommend?? We will get battery disconnect device too.

All 120 volt trailer outlets work fine.

We are going to try and test the converter next.

We could not get an appt at the RV dealer / shop this weekend. We will take it in next weekend if necessary...

Thanks again everyone!

It sounds like you have a dead battery, but here's a couple of things I would look at or consider.

Did you at any time plug the trailer shore power cord into an electric clothes dryer outlet in the garage? This would be bad as those outlets are 240v.

The trailer is not new but you bought it from a dealer. Did they give you any type of warranty? Will they at least look at it for free and see if it's something simple?

Was the battery disconnected for the drive home? If so could you have connected the battery backwards? Make sure that the wires from the negative (-) post on the battery go to the frame of the trailer. Make sure that none of the positive wires go to the frame.

Check for any blown fuses on the positive wires from the battery to the trailer.

Check the circuit breakers in the power panel. Don't just look at them, disconnect the shore power and turn them all off. Give them each a firm push in the off direction to make sure they are all the way off. Now flip them all back on and plug in the power cord.

Do the 120 v outlets work in when plugged in, or are they dead also?

Couldn't we assume that if the leaf blower tripped the breaker, the OP would have noticed immediately there was an issue with the garage power?