# Need Help On 12v Problem!



## Fanatical1 (Jan 9, 2006)

I picked up the camper an hour ago and I have a problem that I could use advise on. Were going camping on Thursday afternoon and I'm
leaving to go out of town in the morning so I need to solve this tonight or fix it on the campout this weekend and electrical problems are not
my strongest skill.









Ok here it is......

I recently installed two trojan 6V and a battery disconect switch and used the camper a couple of times and all is good with my wiring so far.

Picked the camper up today and turned the disconect switch to on and I had no power at all. Could not use the electric jack and nothing
worked in the trailer. I was not happy since the whole idea of the adding the switch was to make sure this stuff did not happen when I stored my camper.
I assumed it leaked juice over the 2 weeks it sat unused somehow, but I was sure the switch was off so I'm confused.

I get the trailer home and plug it in and I have 110 that works but still no 12V??? Fridge won't start and no lights ect.. Then it get's weird,
the 12V comes on for a about 10 seconds and then quits again. This happens several times in a half hour or so. I unplugged the truck so
that is not a variable but I am plugged into 110 from my house. I was able to get the 12V to come on for these brief 10 seconds by turning
breakers on and off??

I checked the batteries with my meter and find they have almost a full charge 6.80V per battery!?!? Now I'm thinking the batteries are good but
I'm not getting the 12V to the camper for some reason. I check the volts from the ground to the trailer to the battery disconnect switch and find
I have 14.04V on the right side of the switch and only .24V on the left side of the switch (picture attached). I flip the switch back and forth (on and off)
and still get .24V on the left side. I assume this means my problem is that my new disconect switch is bad???

And I did use the disconect switch to break the positve line to the camper not the negitive.

Help!

Mark


----------



## GarethsDad (Apr 4, 2007)

Check the voltage at the 12V autoreset breaker. It sounds like its tripping and resetting. James


----------



## Fanatical1 (Jan 9, 2006)

GarethsDad said:


> Check the voltage at the 12V autoreset breaker. It sounds like its tripping and resetting. James


OK

Two questions...

Where is the autoset breaker? I will check it!

If I don't have a good voltage after the disconect switch (left side) how could anything work on 12V? Then again, how could I have
temporary 12V??? I'm confused!


----------



## GarethsDad (Apr 4, 2007)

Fanatical1 said:


> Check the voltage at the 12V autoreset breaker. It sounds like its tripping and resetting. James


OK

Two questions...

Where is the autoset breaker? I will check it!

If I don't have a good voltage after the disconect switch (left side) how could anything work on 12V? Then again, how could I have
temporary 12V??? I'm confused!
[/quote]
The 12V auto breaker will be mounted to the TT frame behind the LP tanks and should have a red rubber/plastic cover on it. The best way to find it is to follow the 12V black wire, from the battery to the frame. Also you may want to remove the cutoff switch to see if it is part of the problem (not engaging). James


----------



## SoCalOutback (Dec 18, 2005)

GarethsDad said:


> Check the voltage at the 12V autoreset breaker. It sounds like its tripping and resetting. James


OK

Two questions...

Where is the autoset breaker? I will check it!

If I don't have a good voltage after the disconect switch (left side) how could anything work on 12V? Then again, how could I have
temporary 12V??? I'm confused!
[/quote]
The 12V auto breaker will be mounted to the TT frame behind the LP tanks and should have a red rubber/plastic cover on it. The best way to find it is to follow the 12V black wire, from the battery to the frame. Also you may want to remove the cutoff switch to see if it is part of the problem (not engaging). James
[/quote]

It looks like the disconnect switch is before the auto-reset breaker. A quick way to tell if it is the disconnect switch is to connect the leads on the left side direct to the battery and see if the problem goes away.


----------



## CamperAndy (Aug 26, 2004)

The disconnect should be on the negative side.

Back to the issue at hand. It sounds like your switch is in fact failed, if the switch is in the closed position and you only have .25 vdc on the one side then you are not getting power through the switch.


----------



## CamperAndy (Aug 26, 2004)

Looking at the picture a little more. Is it only held on with 1 screw? If it is then your switch may not be bad but pulled a part. The lower mounting hole of the switch if it does not have a screw through it then the contacts may not make in the switch. Place a bolt in the lower hole and tighten it up and try every thing again.


----------



## Fanatical1 (Jan 9, 2006)

OK. Thanks for the advise everyone. Here's what I did.

I just moved the positive wire on the left side of the disconect switch that feeds the auto reset to the right side of the disconect switch which
effectively bypasses the disconect switch altogether and now everything is working OK. Fridge stays on, lights on, radio on.... Looks like
it may be the disconect switch. Again, I had 14V on the right side of the switch and virtually nothing on the left side of the disconect switch.

But here's where I am still second guessing myself. The radio still came on all by itself every 10 minutes or so for about 10 seconds while 
I'm checking things out. Not only the radio but the fridge and lights also went on for this short time. If it's the disconect switch (which I hope it is) how could 12V power find itself to the radio, fridge and lights for these brief times? Can these be fed through the breaker/charger box via the 110 and not through
the batteries? If so why did they trip so quickly? I still am connected to 110 this whole time.


----------



## Fanatical1 (Jan 9, 2006)

CamperAndy said:


> Looking at the picture a little more. Is it only held on with 1 screw? If it is then your switch may not be bad but pulled a part. The lower mounting hole of the switch if it does not have a screw through it then the contacts may not make in the switch. Place a bolt in the lower hole and tighten it up and try every thing again.


Two wood screws through the plastic case on the switch to mount it in the treated lumber bracket. Not sure if that is the problem? Bottom screw is
not visable in the picture and neither screw comes in contact with anything other than the plastic mount of the switch and the wood.


----------



## CamperAndy (Aug 26, 2004)

If the switch is arced from not having solid contact (due to not being held together with both mounting screws) then when cool it can pass electricity but heats up and breaks the connection. It can be 10 minutes to cool and only 10 seconds to heat up.


----------



## CamperAndy (Aug 26, 2004)

Fanatical1 said:


> Looking at the picture a little more. Is it only held on with 1 screw? If it is then your switch may not be bad but pulled a part. The lower mounting hole of the switch if it does not have a screw through it then the contacts may not make in the switch. Place a bolt in the lower hole and tighten it up and try every thing again.


Two wood screws through the plastic case on the switch to mount it in the treated lumber bracket. Not sure if that is the problem? Bottom screw is
not visiable in the picture and neither screw comes in contact with anything other than the plastic mount of the switch and the wood.
[/quote]

Tighten the screws, if the wood dried out some the screws can loosen some. The switch housing must be compressed. Also is the pin on the key straight? If it is bent it may not push the contact together enough. Try your spare key.


----------



## Fanatical1 (Jan 9, 2006)

CamperAndy said:


> If the switch is arced from not having solid contact (due to not being held together with both mounting screws) then when cool it can pass electricity but heats up and breaks the connection. It can be 10 minutes to cool and only 10 seconds to heat up.


Andy,

Thanks

I'm listening and open minded, but I used the camper for 2 weeks without issue and when picking it up today (after sitting for two weeks) it was cold and the switch was off and I had no power. When mounting this in the wood, I used two 1/4 inch wood screws to hold it in place.

Here's a pic...


----------



## Fanatical1 (Jan 9, 2006)

CamperAndy said:


> Looking at the picture a little more. Is it only held on with 1 screw? If it is then your switch may not be bad but pulled a part. The lower mounting hole of the switch if it does not have a screw through it then the contacts may not make in the switch. Place a bolt in the lower hole and tighten it up and try every thing again.


Two wood screws through the plastic case on the switch to mount it in the treated lumber bracket. Not sure if that is the problem? Bottom screw is
not visiable in the picture and neither screw comes in contact with anything other than the plastic mount of the switch and the wood.
[/quote]

Tighten the screws, if the wood dried out some the screws can loosen some. The switch housing must be compressed. Also is the pin on the key straight? If it is bent it may not push the contact together enough. Try your spare key.
[/quote]

I will tighten the screws and check. Thanks.. Tried both keys and everthing works as it should. I even cycled the switch multple times (on and off) while checking the voltage and never got the slightest spike in power on the left side. Key was in and the switch was on.


----------



## outback loft (Sep 22, 2008)

CamperAndy said:


> The disconnect should be on the negative side.
> 
> Back to the issue at hand. It sounds like your switch is in fact failed, if the switch is in the closed position and you only have .25 vdc on the one side then you are not getting power through the switch.


I am not sure why everyone on here is using the negative as the break for the disconnect switch. In all the time I have spent doing automotive and marine electrical, the positive is generally the break for any switch, when it is done with the negative then there is still the chance for power to work. For example a negative wire comes loose in the distribution panel (which is separately grounded to the frame) and touches the negative terminal for the battery. Voila you now have power. (I know the chances of that are slim, but it still could happen) There is also the chance of when working on the panel you touch a positive to the negative terminal. (again, a very rare but possible occurrence)

Just my .02

Brent

And it is sounding like the switch is bad.


----------



## Fanatical1 (Jan 9, 2006)

GarethsDad said:


> Check the voltage at the 12V autoreset breaker. It sounds like its tripping and resetting. James


OK

Two questions...

Where is the autoset breaker? I will check it!

If I don't have a good voltage after the disconect switch (left side) how could anything work on 12V? Then again, how could I have
temporary 12V??? I'm confused!
[/quote]
The 12V auto breaker will be mounted to the TT frame behind the LP tanks and should have a red rubber/plastic cover on it. The best way to find it is to follow the 12V black wire, from the battery to the frame. Also you may want to remove the cutoff switch to see if it is part of the problem (not engaging). James
[/quote]

James,

I did check the auto breaker after reading your post and had no power there also.

Mark


----------



## CamperAndy (Aug 26, 2004)

outback loft said:


> The disconnect should be on the negative side.
> 
> Back to the issue at hand. It sounds like your switch is in fact failed, if the switch is in the closed position and you only have .25 vdc on the one side then you are not getting power through the switch.


I am not sure why everyone on here is using the negative as the break for the disconnect switch. In all the time I have spent doing automotive and marine electrical, the positive is generally the break for any switch, when it is done with the negative then there is still the chance for power to work. For example a negative wire comes loose in the distribution panel (which is separately grounded to the frame) and touches the negative terminal for the battery. Voila you now have power. (I know the chances of that are slim, but it still could happen) There is also the chance of when working on the panel you touch a positive to the negative terminal. (again, a very rare but possible occurrence)

Just my .02

Brent

And it is sounding like the switch is bad.
[/quote]

Brent, sorry not going to happen. It is only a circuit if it makes it back to the battery. There is only one connection from the battery negative to ground, open it and you can touch ground wires ALL day long to the 12 vdc positive and noting will happen.

On a battery disconnect the switch is placed on the negative for two primary reasons.
1 - Only one wire is ever connected to the negative side while you may find many connected to the positive side.
2 - when wrenching on the wires for the switch you can ground the wrench and cause no issue, do that on the positive side (while the negative is still connected) and you weld the wrench in place.


----------



## Fanatical1 (Jan 9, 2006)

outback loft said:


> And it is sounding like the switch is bad.


I think so too but if that is the case how could the 12V turn on regularly for 10 seconds at a time when I consistantly read .25 volt off the 
switch? Dumb question but is there a place for the .25V to build up enough to start stuff every so often or is it being fed by the converter
somehow on 110?


----------



## CamperAndy (Aug 26, 2004)

Fanatical1 said:


> And it is sounding like the switch is bad.


I think so too but if that is the case how could the 12V turn on regularly for 10 seconds at a time when I consistantly read .25 volt off the 
switch? Dumb question but is there a place for the .25V to build up enough to start stuff every so often or is it being fed by the converter
somehow on 110?
[/quote]

No


----------



## Fanatical1 (Jan 9, 2006)

OK... I'm not going to get too hung up for the moment on why things ran for a few seconds once in a while. Here's what I know, since I bypassed
the disconnect switch all the 12V is working for the past hour which is a promising sign for camping this weekend.









Mark


----------



## CamperAndy (Aug 26, 2004)

Fanatical1 said:


> OK... I'm not going to get too hung up for the moment on why things ran for a few seconds once in a while. Here's what I know, since I bypassed
> the disconect switch all the 12V is working for the past hour which is a promising sign for camping this weekend.
> 
> 
> ...


That is a workable fix. Let us know if you find out what is wrong with the switch.


----------



## outback loft (Sep 22, 2008)

CamperAndy said:


> The disconnect should be on the negative side.
> 
> Back to the issue at hand. It sounds like your switch is in fact failed, if the switch is in the closed position and you only have .25 vdc on the one side then you are not getting power through the switch.


I am not sure why everyone on here is using the negative as the break for the disconnect switch. In all the time I have spent doing automotive and marine electrical, the positive is generally the break for any switch, when it is done with the negative then there is still the chance for power to work. For example a negative wire comes loose in the distribution panel (which is separately grounded to the frame) and touches the negative terminal for the battery. Voila you now have power. (I know the chances of that are slim, but it still could happen) There is also the chance of when working on the panel you touch a positive to the negative terminal. (again, a very rare but possible occurrence)

Just my .02

Brent

And it is sounding like the switch is bad.
[/quote]

Brent, sorry not going to happen. It is only a circuit if it makes it back to the battery. There is only one connection from the battery negative to ground, open it and you can touch ground wires ALL day long to the 12 vdc positive and noting will happen.

On a battery disconnect the switch is placed on the negative for two primary reasons.
1 - Only one wire is ever connected to the negative side while you may find many connected to the positive side.
2 - when wrenching on the wires for the switch you can ground the wrench and cause no issue, do that on the positive side (while the negative is still connected) and you weld the wrench in place.
[/quote]

Ok well that sounds right, I have just always stayed with the positive because of my thinking of household wiring as well, but i guess in the 12 volt work it works that way.


----------



## hazmat456 (Jul 26, 2007)

outback loft said:


> The disconnect should be on the negative side.
> 
> Back to the issue at hand. It sounds like your switch is in fact failed, if the switch is in the closed position and you only have .25 vdc on the one side then you are not getting power through the switch.


I am not sure why everyone on here is using the negative as the break for the disconnect switch. In all the time I have spent doing automotive and marine electrical, the positive is generally the break for any switch, when it is done with the negative then there is still the chance for power to work. For example a negative wire comes loose in the distribution panel (which is separately grounded to the frame) and touches the negative terminal for the battery. Voila you now have power. (I know the chances of that are slim, but it still could happen) There is also the chance of when working on the panel you touch a positive to the negative terminal. (again, a very rare but possible occurrence)

Just my .02

Brent

And it is sounding like the switch is bad.
[/quote]
any vehicle that I have ever worked on, all of the interior switchgear is ground switched before the relay. Power windows,doorlocks,wipers, even headlights, take a wire at the switch and touch it to ground and it will close a relay to activate the device.


----------



## Airboss (Jul 14, 2007)

Fanatical1 said:


> If the switch is arced from not having solid contact (due to not being held together with both mounting screws) then when cool it can pass electricity but heats up and breaks the connection. It can be 10 minutes to cool and only 10 seconds to heat up.


Andy,

Thanks

I'm listening and open minded, but I used the camper for 2 weeks without issue and when picking it up today (after sitting for two weeks) it was cold and the switch was off and I had no power. When mounting this in the wood, I used two 1/4 inch wood screws to hold it in place.

Here's a pic...









[/quote]

Just adding my $.02 - I've had two of those switches fail. No kidding. Typical Harbor Freight junk. I'm going to replace mine with high quality marine parts as soon as I find one I can afford.

Stop second-guessing yourself and replace the switch. I'll bet that sets you straight!

Good luck!


----------



## outback loft (Sep 22, 2008)

Airboss said:


> If the switch is arced from not having solid contact (due to not being held together with both mounting screws) then when cool it can pass electricity but heats up and breaks the connection. It can be 10 minutes to cool and only 10 seconds to heat up.


Andy,

Thanks

I'm listening and open minded, but I used the camper for 2 weeks without issue and when picking it up today (after sitting for two weeks) it was cold and the switch was off and I had no power. When mounting this in the wood, I used two 1/4 inch wood screws to hold it in place.

Here's a pic...









[/quote]

Just adding my $.02 - I've had two of those switches fail. No kidding. Typical Harbor Freight junk. I'm going to replace mine with high quality marine parts as soon as I find one I can afford.

Stop second-guessing yourself and replace the switch. I'll bet that sets you straight!

Good luck!
[/quote]

That type of switch is good, but you need to get the marine version of it, Go on line and search for Perko marine battery switch.


----------

