12V partially working/Control Panel Issue?

[rayandre]

When we bought out 70 Overlander it didn't have a battery. I finally got around to installing one and noticed the 40amp fuse had been blown ages ago for the Trailer battery so I swapped it for the TV 40 amp fuse and the interior lights work fine but I couldn't get my water pump switch to turn on or anything on the Control Panel to work. Haven't taken a meter to any of the switches or bulbs yet but I was curious to know if anyone else had come across this problem? Everything works fine when plugged into shore power so I know everything works. I'd like to get the 12V side working well so we can dry camp if possible when we go out west this summer.

[NevadaGeo]

Maybe look for some more switches or fuses in another panel. Maybe the control panel needs a ground wire. Or get the meter out and find out where you have hot and where you have ground.

[rayandre]

Thanks for the reply. The meter will be next. I don't believe there are any other switches that I am aware of-the panel works fairly well on 110. Odd. Panel repair might be my next business! The factory didn't want to really deal with it last time I was there.

[Stumpjumper]

It's really easy to short something out when removing/installing the face of the control panel. Happened to me. Check the DC fuses after inspecting and reinstalling the cover.

[TG Twinkie]

Pull the fuses before removing the control panel.

[WineStream]

Do you have the in-wall oven? Have you checked the fuse panel on the univolt? There is a separate DC power feed to each side of the trailer. I had a similar problem when I bought my '74. In the end, I found that the wire to the oven light switch had written through the wire insulation and was shorting out on the interior skin.

[rayandre]

No in wall oven-all in one unit on ours. I checked the Univolt fuse panel before I looked at the Control Panel (there are 6 in it I believe-4-20's and 2-40's) and the only one that was fried was the trailer battery 40 amp so I swapped it for the 40 amp TV fuse which is how I got part of the 12V to work at all. All other fuses look good but until I get a meter on it I guess I can't be sure-but it is pretty clear to see a blown fuse usually. I saw a fuse in the back of the Control Panel and it also looked fine. My main issue at the moment will be to see if 12V is getting up to my brakeaway switch on the tongue. Especially since we do not plan to camp this summer without being plugged in and I don't have a generator yet. I'm also hoping to ad an electric tongue so the 12V up front will be important.

[Dumpster]

First off, forgive any typo's, doing this on the phone. If I understand your original post correctly, all 12V accessories work connected to shore power? Boiling this down, that means that your converter/charger is converting 120A/C to 12 VDC. Period. Univolt? BTW, these are total crap, and should be replaced immediately if you want your battery to live. No offense intended. Seriously. Sorry for the aside. In a nutshell, your battery is not tied into the DC side of the system. It cannot be. If everything 12V works on shore power, it is coming from the Univolt. Disconnect shore and all goes dead, battery offline somewhere (or somehow completely dead). Disconnect battery and check voltage. Now check voltage at Univolt with shore power. My guess is around 13.5-14 volts. Now reconnect battery, disconnect shore power and test voltage anywhere you can on the DC side, other than the battery. Try a 12V outlet in living room. My bet is that you have no DC anywhere, including the control panel. If it were a short in the DC-side, it would present itself while on shore power also since there is typically and unfused, direct link between the two. So if a short was present, nothing DC would work on shore power either. Is your battery in original location in the trunk? Look between there and the Uni. Also keep in mind that in the situation you describe, your break-away switch will not operate should your TV separate from the trailer, unless you have another, designated battery on the tongue. Bad JuJu.

Good luck.

[rayandre]

Dumpster, thanks for the reply to my thread. I understand the Univolts are junk (and would never take offense to that-just a fact and I didn't design it so no harm done) and I do plan to replace it but I was hoping to get by for this trip-may not happen. NOTE:I DO have some 12V which is why I was confused. I have overhead lights but I haven't checked the 12V outlets and I haven't taken a meter to the breakaway switch but that's my next move. Next would be to replace all fuses or at a minimum test them even though most look good. The 40amp trailer battery fuse was definitely blown when we bought it-who knows why. That's why I swapped it for the 40 amp TV battery fuse and hooked up the battery to see what worked or didn't. Having a fun time finding a 40 amp glass fuses-seems no auto parts stores carry them anymore around here-yet another reason to change to blade fuses I guess. The reason I was going through this (before replacing the Univolt) was to understand what worked and what didn't work since we don't know the history of this beast and we know the PO's didn't have a clue. Given that, and given we just now put a battery in to see if the 12V worked, I'm just trying to establish a base line of operation so that, when I do replace the Univolt (and possibly the fuse block) I can hook it up and not freak out that something (like my control panel) isn't working and wonder if I mis-wired something or screwed something up-which is always possible. I did the same thing with the propane before replacing the lines, tanks and regulator. I know it may be overkill but I'm still learning a lot about these units which is usually fun and at times frustrating. Our 70 is really more in line with a 69 (and built in Oct. 69) and yes we do have the battery in the trunk-Univolt in a side compartment by the shower side.

[Dumpster]

I am certain that this has stretched the limits of my electrical knowledge. The only other thing I could possibly speculate (heavy, heavy emphasis here) is that somehow while unplugged, the Univolt is turning resistive? I don't know if that is possible, as I think all it really is, is a big transformer. But I can't think of any other explanation for things working with it plugged in, and not when it isn't.

My theory is that something in the Univolt has failed, causing it to to create a resistive load when unplugged. There is enough juice left over to power the lights (which can usually operate well below their intended voltage, and don't draw much for amperage), but not enough for something that draws much higher amps, like the water pump.

I never looked my Univolt over that closely. However, I do remember that it has a power distribution/fuse panel built into it. I would look that over and see if you can't determine where the Univolt power comes in. It should be 8 gauge, and parallel with the wire coming off the battery. If that can be disconnected, you can take the Uni offline. Just be sure to check the voltage on your battery to be sure it is good before you test out the pump. The Uni could have drawn it down if my theory is somehow miraculously correct. My Uni worked, but was only capable of putting out enough amps to run lights. It could barely even hold the battery's charge.

FYI- I got my 60 amp Intelli-Power (PD9260) smart charger/converter off Ebay for around $150 shipped.

My two cents, likely worth far less than that. You might try posting in the Technical Section under Electrical. You might draw the attention of someone who is actually qualified, unlike myself. Pinging Zep!

[rayandre]

Luckily this weekend's weather will be perfect for running through all of this. I'll get my meter, check the battery voltage, test fuses and see where I do have what voltages within the control panel. I am totally new to the 12V side of life and have so many other things to get together. I've been looking at a few new converters and hope to do this before our trip out west in July. Did you also replace your fuse block with a newer blade type fuse block? What did you do about a 50 amp or 40 amp breaker-or shunt for the TV and Trailer battery? The Univolts fuse block has 2-40's.

[Dumpster]

The fuse panel VTS carries is passable. It is pretty well made and under $40. I'm not crazy about its layout, or that it's metal

I actually used a circuit breaker instead of a fuse. It is resettable, and has a lever to cut power. I had it left over from my car audio days( that is a good arena to look for one).

I think the meter is going to open your eyes up quickly. FYI-rivet heads in the inner skin make a great ground test point

[bsporcich]

I have a 69 that may have the same Control Panel as yours. Please see my post in the Electronic's section...


http://www.airforums.com/forums/f317...lp-103434.html

If you have this control pannel and assocated circuit board would you mind sending me a good close up picture of the circuit board?

Sorry to be not helping you with your problem, I feel like a leach! But getting disperate.


Bill

[rayandre]

I'm going to try to attach a pic of our panel-never done it before. If it doesn't work send me your email and I'll forward any pics of the panel you need. Ours is more like the 70's. Let me know if you want me to shoot the circuit board from it since it's not the same as your panel.

[bsporcich]

Yes your pannel does look different from the outside. If it is no problem for you, would you look to see if the circuit board looks about the same as mine, if it does please do send me some pictures. And thank you so much for taking the time to assist.

Bill

[rayandre]

Sure thing. I replaced all the fuses in my fuse block after searching a long time for the 40 amp AGS fuses-finally found them at a small RV dealer locally-they tucked away in a box of fuses-real mom and pop operation-just what the doctor ordered. So lucky. After replacing all the fuses and realizing the PO had put in the wrong mixed match bunch of fuses I did manage to get the pump switch to work! Yeh! every small success at this point is great in my book! I then took my meter to the tongue and tested the connections to my brake-away switch and I had 12.64 volts-Yeh again! All my 12V outlets inside worked, fans worked and lights worked. Next up will be to meter the panel and see if I'm missing anything there because my tank level indicator light isn't turning on-which it did on 120V-not that it really matters because I'm not sure how accurate the sensor is on my fresh water anyway. At least I'm moving in the right direction on this beast!

[rayandre]

Here's some pics I made from our manual regarding the schematics of our panel. I thought it might be more useful to post these since this is exactly what I see when I pull the panel and look at the mess up there! First one is a cutaway, second one is a schematic of the way it's laid out and the last is the circuit itself.

[rayandre]

let me know if you need a bigger version to print or blow up. I can send these via email much larger if you give me your email. This site only allows smaller files so I downsized to post.

[bsporcich]

Thank you for taking the time to send these pictures, they are somewhat helpfull. I can see that your circuit board is slightly different than mine and I really need a schematic or close up picture of the 1969 board. Bummer. Anyway, how is your electrical problem going... all solved now?

[rayandre]

I'll try to take a close up picture of our board and post it-unfortunately there is a size limitation to what we can post on this site. If you can somehow email me directly, I could email a larger file of the close up so you have some real detail to look at. My email is: rayjuaire@gmail.com-let me know and I'll get it done. After I replaced all of the fuses in the original fuse block that seemed to solve the water pump switch issue so now I'm going to go through and swap the fuse on the panel itself and see if I can get some bulbs for it too. So far so good-maybe not 100% but better. Thanks-Ray