Electical Probelm

[Terry6]

Ok all you electricians, here's the problem. :laugh: Sometimes 12 volt system goes off when I turn the lights on. Also the refigerator goes off when it is turned on gas. When this happens I start the generator for a minute or less, when I shut it off the 12 volt system works again. Years ago we had a problem with our refrigerator going off when we used one of the only floresent light we had in our rig. I disconected the light, problem solved. I was thinking short, but it never blows a fuse, so now I'm thinking converter. The contact points worked the one time tonight, but I don't know how to check them further. Any help will be appreciated. Thanks. Terry

 

[ARCHER]

Electical Probelm

Terry,
Have you checked your batteries to make sure they are charged completely and are recharging as usage drains them? Are you in a Motorhome, camper, or what? Does you unit have aux batteries that run your 12 volt items and when hooked to shorepower (AC) does everything work OK. Is your charger working properly (charging the 12 volt batter(s)? Are all your circuit breakers working properly?
I'm sure there are some electrical wizards that will guide you better than me, but just some suggestions.

 

[TexasClodhopper]

Electical Probelm

Terry6:

What you describe sounds like a 'loose' connection. Seems like a connection is 'broken' when current is demanded by a system, but 'contact' is made again when the 12v is boosted by the generator. With it affecting as many systems as you are describing, I would be looking at a major distribution point all the way up to the battery. It could even be a common grounding point. On my RV all the 12v grounds come together at one point on the frame. If that ever got 'loose', it would make intermittant connections. I wouldn't be looking for a "short". That would certainly blow a breaker/fuse.

 

[Terry6]

Electical Probelm

Thanks ARCHER and TexasClodhopper, we have a 1983 Suncrest class A Motorhome. In put a meter on the batteries today and they both read 12.00 volts. I get 11.63 volts at the convertor, 11.34 volts with 4 lights on. Refrigerator has 11.94 volts at the main terminal block. I have not had time to trace the ground yet, but will try to as soon as I can. Thanks again for your help. We will be leaving for Northen Ca. and Nv. next weekend, but I will post as soon as I can find a fix. Happy traveling. Terry6

 

[TexasClodhopper]

Electical Probelm

Terry6:
Remember that the voltage at those points doesn't mean a lot unless those appliances are actually 'on' and drawing current from the batteries. Put your meter at some 'point' that you want to check and then have someone turn on the appliance. If the voltage drops 'way down' at that appliance, you may have found out some info on where there 'might' be a 'loose' connection.

 

[Terry6]

Electical Probelm

Thanks TexasClodhopper, I'll try that tonight, and get back to you. :laugh: Terry6

 

[Terry6]

Electical Probelm

TexasClodhopper, I put my meter on the frig. and it droped 12.03 to 11.94 volts. Do you think that enough to cause the problem. I had to get the rig back to storage before 7:00 P.M. so that's all I had time for today. I will do more as soon as I can. Thanks, Terry6

 

[TexasClodhopper]

Electical Probelm

Terry6:
A drop from 12 to 11 would be normal for a 'higher' current appliance. A 'loose' connection would tend to 'split' the voltage between the 'loose' connection and the appliance. I would say that you haven't proven a 'loose' connection in the frig circuit. You're looking for 'close to' NO voltage at an appliance where there is an intermittant connection rather than 'close to' the 12 volts.

BTW, in your original post, you mentioned "contact points" so don't forget to probe around there, too.

 

[Terry6]

Electical Probelm

TexasClodhopper, I will be checking those Contact points and plan to run a ground wire to the frame. Thanks again for all your help. Terry6

 

[Terry6]

Electical Probelm

TexasClodhopper and ARCHER, problem sloved. :laugh: It was the contact points at the converter. I used my air compressor to blow the converter box out and sprayed the points with electircal contact cleaner. Now we will be off for cooler climates for the next 3 weeks. I know I've said it before but, I really want to thank you both for your help. Happy traveling, Terry6

 

[ARCHER]

Electical Probelm

Terry6, That's great. Sure glad you solved your problem. There are a lot of great folks that respond to RVers problems/issues on this site. I've learned enough to last me a life time and hope I can share some of what I have learned in the last two years. Lot's more to learn.....but I never worry about asking even the silliest of questions here.
Good luck and stay safe.... :laugh:

 

[TexasClodhopper]

Electical Probelm

Terry6:
Whoa that hos down, podner! Perhaps all you've done is 'locate' the problem with your contact cleaner. Something has caused those contacts to start 'going bad', so I would be looking for a replacement very soon as well as a reason for this to happen. I'm not at all sure what 'contacts' these are, but I know there is a reason for this to happen. :approve:

Having said that, here's hoping that your next 3 weeks are free of this problem (or that you have plenty of contact cleaner handy!)

 

[Terry6]

Electical Probelm

LOL, I know what you mean TexasClodhopper. :laugh: When we get back I will let you all know how it went. Like ARCHER, I have alot to learn and it's great to have folks to help us along the way. All I can say is, Thank God for generators and full hook-up camprounds, and last but not least, RVUSA, :laugh: Now getty up Hos.

 

[camperdog]

Electical Probelm

Terry6, sounds like you have a tri mode refrig ;110/12v & propane. We have a tri mode Norcold unit in an old 1988 Mobile Traveleer we use, and this year the LP mode started to quit after 30 seconds. We switch to LP, the check light goes out as if the propane burner has started up, then the check light comes back on, and the burner goes off. We never really figured it out, but if we set the fridge thermostat to no colder than "3" out of five, the propane burner stays on. This lets us move from campground to campground, and is actually more efficient that 12V mode. Hope this helps.

 

[Terry6]

Electical Probelm

Thanks camperdog, we just got home from a 3 week trip to Northern Ca. The frig. is a two year old Dometic and is only 110 and propane. The only problem we had with the frig. on this trip was that the temp. was running as high as 50 degrees, so I called a service man just outside Fresno Ca. and he told me to unplug the thermetor (a $12.00 part) and that solved the problem. He also told me to plug it back in when we got up to Tahoe where it was much cooler. The temp. inside the frig. got as low as 28 degrees overnight and stayed between 34 and 39 during the day. Now all I have to do is find out how to replace the termetor so the frig. is not running wide open all the time. :laugh: Thanks again camperdog, TexasClodhopper, and ARCHER for all your help. :laugh: Terry6

 

[Gary B]

Electical Probelm

Hi Terry6, is it an Americana model with no temp adjustment(that is its all automatic)? If so there maybe nothing wrong with the thermistor, just the way that they work, I think (and I maybe wrong) that Dometic has a thermistor adjuster that plugs-in between the CB and the thermistor itself, really what it is, is a resitor that fools the circuit board into thinking its warmer in the box. By unpluging it you bypassed the temp regulator protion of the circuit board and it cooled full time as you know, and got you by. :laugh: :bleh: :approve:

 

[Kirk]

Electical Probelm

Terry 6,

Wondering what happend with the 12V power problem. As a retired tech. I just have to know more about this one. Since starting the genset solves the problem it has to be related to the 12V supply. When you start the genset, you are supplying 120V-AC to your converter and it in turn is supplying the extra 12V-DC power to get you back up again. A motorhome genset does not supply any 12V-DC, but only supplies 120V-AC which supplies the converter. You didn't say how old the batteries are or if you have taken a close look at the cables and the connections to them? I would look at them very closely and if you have not done so, clean the cables and the battery posts very carefully. You may want to use a dialectric grease (which you can buy and any home supply store) to them as well just to improve the connection.

In thinking about your problem, it seems as though it happens when you increase the power requirements by turning on something. Do you turn things off when you start the genset to get it going again, or just leave them on and let the converter assume the load?

Here is another test just to confirm that the converter is what is picking up the load. Try running the DC with shore power available, but not connected, then plug in shore power when the 12V power fails. I bet that will make the problem go away as well. But that still doesn't answer what is happening?

Do you have a schematic of the electrical systems? This has to be a problem in the area of the batteries, or some common point. In most RVs the output of the converter is connected to the battery terminals as the connecting point for all loads, the battery and the converter. To me, it seems that the problem has to be either in the connections or the batteries. You don't say if you have one battery or two, but if two, try removing the batteries one at a time and see if using only one battery makes a difference.

And keep us posted as to what is happening!

 

[Terry6]

Electical Probelm

Hello all, sorry to take so long to reply. My mom's ill health, and work have left little time for anything eles. She is better, and the O.T. has slowed down, so here I am. :laugh: Since my original post I have not had the problem. These are the things that I tried. Greased the battery post, made sure the batteries were fully charged, sprayed the contact points, and checked the ground to the frame to made sure it was a sound connection. All things that you all have helped me with, and for that I am very greatful. The problem has not occcurred again and we will be selling the rig soon to make way for our new rig. It gave us very little trouble in the 10 years we have owned it. We went to a class C with two sildes, and added two more feet in length to 29 ft., no more turning sideways to past each other to get to the frig.. :laugh: The sildes were my wifes idea, she has a good one now and then. Gee, I hope she doesn't read this :laugh: I want to thank you all for your help, God Bless, and keep the wheels right side up. Terry and Martha