12 volt circuits dead when on hookup...

Yeah, and that breaker is an installer added device, so may not even be there. In any case, it would disconnect the battery from the house circuits if open and Bryan says he has 12v power from the battery, so I doubt if that is it.

Yes, Lou, you did say "older Magnetek converters". I was just cautioning not to place too much faith in them, since the 73xx uses a different converter technology than the 63xx.

From what i can see, only the blue wire is a 12v output from the converter and nothing goes direct to the battery from the converter itself.

Terminal "C" goes directly to the battery.

(edit)
OOOPS!  Sorry,  I guess that would be on the distribution/fuse panel and NOT what you were referring to as the "converter itself".

Bryan's symptoms are so strange that I'm now chasing myself in circles

Bryan said:

Possibly, but the parallax should power the 12v circuits even if a battery is not present.

Click to expand...

I'm with Lou here ... I'd get a good battery, even a starter battery would do as long as it's charged up and see what happens when it is connected.  You said it works ok with a battery charger connected.

Not at all familiar with your unit, but what if for instance there is a relay or solenoid somewhere in the circuit that gets it's power from the house batteries ... bad battery ... no power to pull in ... would do as you say.

Looking over the thread from the beginning, the post where you connected the battery charger (good 12V) was the only place where you symptoms changed ... aka ... system worked. 

Just an idea ... but if it were me I would get that bad battery out of the picture, even if with a temporary good one ... that may be causing you to go in circles  ...  this is one of those, don't ask me how I know that deals!   :  ;D

Good luck,

Howard

Howard Rawley said:

You said it works ok with a battery charger connected.
Looking over the thread from the beginning, the post where you connected the battery charger (good 12V) was the only place where you symptoms changed ... aka ... system worked.  
Just an idea ... but if it were me I would get that bad battery out of the picture, even if with a temporary good one ... that may be causing you to go in circles  ...  this is one of those, don't ask me how I know that deals!   :   ;D

Click to expand...

aka Porky said:

Bryan's symptoms are so strange that I'm now chasing myself in circles
Any reset "button" or "plunger" would probably be located on the circuit breaker (in the positive battery lead) shown on the last page of your diagram(s) link here

Click to expand...

RV Roamer said:

It does show reverse polarity protection fuses, which might result in some strange readings if one or both are blown.
There is also a troubleshooting flowchart:
http://www.parallaxpower.com/7300/Flowchart7300.pdf
which shows the proper method for checking converter output power.

Click to expand...

Hi Howard,

Not quite correct, what happens when I connect the external battery charger (or connect the starter battery to the leisure battery via jump leads) is that the 12v circuits work, proving something, but they are not being powered by the parallax converter, they are being powered by the battery.
This is leading me to think that the wiring is fine, but there is somerhing blocking the converter output.  This seems to be nonsense though as I can measure 13.6 volts all over the 12v fuse board...


Hi Lou,

You and me both    

hmmm....On the last page of that pdf, is the curcuit breaker the thing near the battery with what looks like two terminals on it?

I *think* I may have one of those under the front of the coach near the starter (not leisure) battery...
Quite hard to get at but could that have a reset button/plunger that may be worth feeling for?


Hi Gary,

Polarity fuses okay and troubleshooting guide followed...It concludes converter is okay.  

the starter (not leisure) battery

Click to expand...

Translation from Britlish to Amlish:

the chassis (not house) battery  ;D

Regarding Reset buttons or switches... Most converters use fuses. the reset button, if any, will be elsewhere.

For example the schematic for my battery control switches shows a pair of 30 amp post type (Push in to reset) breakers... What Damon gave me is something else (And way lower maintenance) but that's what the diagram shows.

On my rig the breaker (Which is a self-resetting type) is a good 35 or more feet from the converter.. (And the rig is only 37')

John From Detroit said:

Regarding Reset buttons or switches... Most converters use fuses. the reset button, if any, will be elsewhere.

For example the schematic for my battery control switches shows a pair of 30 amp post type (Push in to reset) breakers... What Damon gave me is something else (And way lower maintenance) but that's what the diagram shows.

On my rig the breaker (Which is a self-resetting type) is a good 35 or more feet from the converter.. (And the rig is only 37')

Click to expand...

John, the reason Damon did it this way was because the batteries were installed away from the BCC.  They wanted a breaker located so that it would protect the long run of wire to the converter an loads.  In my rig, the batteries are within two feet of the BCC, so the internal breakers are used.

Your schematic, provided by Intellitec, just shows what their option would be.

Right, I'm now getting so confused I went out to my rig 10 minutes ago and met myself coming back!


I have now totally remove the house battery.  The +ve lead is hanging in the air and the -ve had been connected to the chassis battery to preserve the integrity of the earth.  (Tell me if I did wrong)


Now, the converter is still measuring the same voltages everywhere but still no lights.

Whilst playing with my meter and measuring everything that I could (the cat look very concerned at one point)  I discovered the following which may help someone come up with a EUREKA! or may, as it did with me, just confuse the issue even more...


(Refer to this doc page 7) Paralax boardhttp://www.parallaxpower.com/7300%20Series%20Installation%20Guidelines%20rev%20A.pdf


When I connect my meter set to vdc I get 13.6v if I connect to number 4 on the fuse board (this is supposedley connected to the battery negative) to the negative earth bar...

But I get no reading if I connect the meter to the earth bar and the connection 1 where the 12v+ve from the converter is attached.

Unless I'm completely crazy this is totally wrong.

Do you agree?

UPDATE:

Looks like I have an earth problem...I think

I was starting to investigate the strange voltage reading between the battery neg connection on the fuseboard and the negative earth bar when I unscrewed the fuse board to pull it forward (don't ask why) and when I was putting it back the rear connection block (which has the converter white wire -ve attached) touched the metal frame of the converter housing...
The lights came on  ;D ???

So, I don't know what is wrong or how to find out but I think this points to an earth/short/wiring issue...

It appears your "earth bar" (or whatever set of termination points are attached to terminal 4) is grounded only if the battery (-) is present. That's not real bad - the battery negative should always be connected to the RV's chassis for grounding purposes - but if you have a bad (corroded) connection somewhere you can indeed get very strange results. Strange problems in an automotive-style 12v system are nearly always grounding problems.

Without seeing your actual wiring it is hard to tell if there should be an additional ground strap on your "earth bar", but that's one thing I would be looking at. The other is the condition of the battery (1) lead and the connection at both ends (battery and chassis).

Hi Gary,

The negative lead that was connected to my house battery is now connected to my chassis battery so that should be taking care of that. 

But it appears that the negative bar connector might actually be live as it gives a +ve reading if I connect my red probe to the bar and the black probe to the negative on the fuse board.

Here's another oddity (I know, I know - another one?)

If I connect the meter black probe to the battery neg connector on the fuse board and the meter red positive probe to the converter housing frame...I get +13.7 volts.

So, could it be a short rather than an earth?

You just anwered your own question. First, you keep reffering to the blue wire as +ve and the white wire as -ve; they are both +12vdc, one comes out of the "converter circuit" inside the converter box, and the other one comes out the "charging circuit" inside the converter box. When you ,mentioned that fuse #4 was ground, it told me that you had a short on that circuit. ALL fuses should be + and yoiu should get a reading either before the fuse or after the fuse when you connect your meter with the red lead on the fuse and the black lead on the metal on the converter box or the ground bar. If you get a - reading, then some wires are reversed or you have a short. To check for a short, measure Ohms between the ground bar and the metal of the converter box; you should read if not mistaken, infinte resistance. If you have a short, it would read 0 Ohms.

Fred, I don't think Bryan meant to say that fuse #4 was ground.  He was referring to (Bullet #4) on page 7 of the diagram.

It sounds to me like all circuits have an open return.  If all circuits have 12v on the fuses, and presumably 12v at the load, and still don't work, then they have NO return path to the source.  They appear to all return to the neg bus bar, but it is not grounded.  The reason the case is hot, has 12v, is because it is connected to the negative (return) side and one or more of the loads are switched on.  The 12v is passing through the load(s) and is present on the return lead(s) looking for ground.

Bryan, here is what I would do.

Unhook from the main power and inspect the incoming ac connections.  The ground lead of the incoming power should be at ground (vehicle frame) potential.  Measure with your ohm meter.  This lead should be attached securely to the metal case of the panel/converter in some fashion.  This is your primary ground connection.

Now, if/when that is confirmed, and the problem still exists, you will need to ensure that all DC loads are turned off (maybe pull all 12v fuses ?) and measure for that 12v on the converter case.  It should be gone.  You still need to ensure that the negative bus bar is grounded (frame ground).  

Since it was stated that this converter should operate without a battery connected, then it must be grounded with other than the battery negative.

Hi Lou,

Thanks for the very involved reply, please see my comments in red 

aka Porky said:

It sounds to me like all circuits have an open return.  If all circuits have 12v on the fuses, and presumably 12v at the load, ...Just removed a bulb and tested, no voltage...and still don't work, then they have NO return path to the source.  They appear to all return to the neg bus bar, but it is not grounded. That makes sense to me

Unhook from the main power and inspect the incoming ac connections.  The ground lead of the incoming power should be at ground (vehicle frame) potential.  Measure with your ohm meter.  This lead should be attached securely to the metal case of the panel/converter in some fashion.  This is your primary ground connection.  Sorry, you lost me there  ??? as I can't understand the relation to the incoming ac; But it may not matter 

Click to expand...

Let me first of all state something wonderful...


...My converter is currently working  ;D ;D ;D

BUT that's not enough of course, because I may have effected a fudge and be storing up trouble for later.

Let me explain... (what follows will sound like fact but is actually my take on what is happening etc. so PLEASE disagree with anything at will  )

The converter provides one circuit of 13.7v  This is available through the 12v fuse board in the converter for any load connected to it.  Along with the lights, ceiling fan etc. is another load...the house battery.  This battery charges itself purely by the fact that 13.7v is greater than the 12.x volts that it has.
The battery positve connection on the fuseboard provides the +ve load connection for the house battery (see number 3 connection in picture on page 7 of Parallax 7355 manual )
The battery negative connection on the fuseboard is connected by a wire on the back to the converter white wire (negative) and by a wire on the front to the earth busbar.
The earth busbar also has connections to the earth wires for the various 12v circuits (lights etc.) and also has a connection to the negative terminal on the house battery.

NOW...

In my case all the strange goings on eventually pointed to bad wiring in or around the converter.
The wire connecting the battery negative on the fuseboard (connection number 4 on page 7 of Parallax 7355 manual to the earth busbar did not seem right.  I couldn't trace it as it goes under the floor and back out again.  When I disconnected both ends from their respective connections and put the meter across it, I did not get continuity.  If I set the meter to ohms where it should have read 0 it read -0.521  Now I don't understand this reading but I know enough to know that the it meant that it was sort of the same wire but not fully - if you understand what I mean.

As an aside here is something I did not tell you for fear of complicating the diags...I have another RV which is also an R-Vision Traillite and it has a 7345 converter.  It is essentially the same and what I can see in there is that the wire in question does indeed run straight from the negative connection on the fuseboard to the earth busbar.

So, taking that as my lead I disconnected the existing wire at both ends and connected the fuseboard negative to the earth busbar with a temporary wire.  The lights came on  ;D
I checked the voltage from the busbar to the negative on the fuseboard (was 13.7v) it was now 0v.  I checked the negative on the fuseboard and the coverter housing (was 13.7v) it was 0v.

So unless this wire that is now disconnected did something else (how would I know) then it *may* be fixed...

Please comment with your thoughts/questions or any checks I can do to double check before I put this to bed  8)

Bryan, I would say that you have fixed it!!!!!!!!!

I don't have any idea what else that white wire did or where it may have been routed to, but if it's necessary then you will find out someday when something else doesn't function correctly.

I didn't mean to confuse you by mentioning the ac wiring, but since your ac panel shares the same metal case with the converter (DC) panel, it too should be grounded to the vehicle frame and would therefore hold the case at ground (earth) potential.

The important thing now is, not only that it works correctly, but that it is properly grounded.

It's possible that someone replaced that converter sometime in the past and that it was not re-wired exactly like the original.

Great that you fixed it and learned a great deal in the process.  Merry Christmas to ya........

Thanks Lou,

And  thanks for clarifying the ac bit....

...cos I'm still working on it  ;D

I have my meter set to 200 ohms (remember that me and meters don't understand each other) and connected to either end of the 'white' wire.  Now sometimes it says 1. which implies a complete break.  But other times it reads various fluctuating ohms.  What's changing?  I'm wiggling the bare copper wire that is attched to the converter (I think within the ac side)

Could it be that the white wire and the copper wire are somehow linked and connected to the chassis?

They should both be connected to the chassis.....  at least they should be electrically connected to the chassis ((ground earth potential)

Okay, white wire back in original position.

A firm push on the bare copper wire under the floor (that is connected to connector 7 through hole 8 on page 2 of Parallax 7355 manual  and the lights come on  ;D

So, it must be a bad connection under the floor so converter will have to be removed and bad connection fixed...

Question,

The earth bonding wire (bare copper one), will it be going to the chassis and if so, why is it not just connected to the earth busbar along with all the 12v earths?

(while you answer that I'll go in the other RV and see where ITS copper earth goes)

Right - Checked the other RV - white wire goes direct from neg on fuse board to earth busbar, 120v earth copper wire goes through floor, presumably to chassis.

So I suppose I *could* just cut the white wire and connect direct, but then I may leave myself with a 120v earth problem which could be a little hazardous if it is not 'good'.

Are you sure that the bare copper wire is firmly connected to the bus bar?  It should be.

In other words;  are you sure the loose connection is under the floor and not there at bar #7.  The copper wire should be part of the ac bundle (romex) supplying ac to the box.

Well I#m pretty sure, the system comes on/off as I push and pull (gently) where the copper wire goes under the floor along with the other wires.  The other end is not moving as I do this...

Why is the copper wire not connected from the #7 connector to the earth busbar that is used for the 12v circuit earths?