Electrical help Needed

[mailyohanPDX]

I have a 1969 - 27Ft - Rear bath - Land Yacht. I am trying to install a new power max converter. I am guessing the previous owner has played with the electrical. Can someone help me to do this right. Please see pictures

[Al and Missy]

1. Does your trailer have a battery disconnect switch, also called the USE/STORE switch in the newer trailers? If so, how is it wired? If not, you may want to add one.

2. Assuming you have a battery disconnect switch, you have to decide how you want the battery and converter to be connected. The older trailers had the battery disconnect switch between the battery and the distribution panel, i.e. in the red wire you show at the top left of the first picture. The converter is wired directly to the batteries, red to red and black to black. In this configuration the converter will charge the batteries any time shore power is connected, regardless of the position of the disconnect switch. This is really a load disconnect switch. When it is in the OFF position there is no 12V power to the trailer systems. With an old, OEM charger, the converter will overcharge the batteries if the trailer is left plugged into shore power for extended periods of time when not in use. If your new converter is a three or four stage, this will not be a problem.

In the newer trailers, the disconnect switch is between the battery and the power panel, but the converter is wired to the power panel. In this case, the battery disconnect switch is just that, it disconnects the batteries from the trailer and the converter. The trailer 12V systems will have power whenever the shore power is connected, regardless of the position of the disconnect. If this is what you want, connect the converter red wire to the very top left screw called car battery, and the converter black either to the battery black screw at the bottom left or directly to the battery negative post. I will admit to being a little confused by the labeling of the car battery screw, indicating BLUE wire. Blue wire is normally brake.

Either way, don't forget to take power from your trailer battery and run it to your breakaway switch if that wiring is not already there.

Lastly, I see two potential problems in your pictures:

1. There is no battery negative cable connected. I'll presume you have it disconnected for this operation.

2. The battery positive cable looks like only a few strands go into the screw lug. If possible to get more in the hole, that end should be cut off and re-stripped to expose more strands.


Al

[mccrosti]

Have you tried calling Powermax? If the PO messed with the wiring, someone might mistakenly provide incorrect information on hookup.

[Lumatic]

You have 2 choices:
1. Salvage the existing fuse panel (those glass fuses are getting hard to find)
2- Put in a new 12v breaker/ fuse panel.
I did #1 and it is still working for me.
What would be real helpful is a electrical diagram and a Service Manual. Airstream does sell copies and sometimes original copies are available on Ebay. I think the first year sevice manuals were published was 1972

[mailyohanPDX]

Originally Posted by Lumatic

You have 2 choices:
1. Salvage the existing fuse panel (those glass fuses are getting hard to find)
2- Put in a new 12v breaker/ fuse panel.
I did #1 and it is still working for me.
What would be real helpful is a electrical diagram and a Service Manual. Airstream does sell copies and sometimes original copies are available on Ebay. I think the first year sevice manuals were published was 1972

Thank you so much for your advice. I think we will keep the old one for a while also [emoji4]

[mailyohanPDX]

Originally Posted by mccrosti

Have you tried calling Powermax? If the PO messed with the wiring, someone might mistakenly provide incorrect information on hookup.

Thank you for your advice, I will have to check with them in the future if my work seem to be wrong. My dad was able to help with it today. Yey, for dads!

[mailyohanPDX]

Originally Posted by Al and Missy

1. Does your trailer have a battery disconnect switch, also called the USE/STORE switch in the newer trailers? If so, how is it wired? If not, you may want to add one.

2. Assuming you have a battery disconnect switch, you have to decide how you want the battery and converter to be connected. The older trailers had the battery disconnect switch between the battery and the distribution panel, i.e. in the red wire you show at the top left of the first picture. The converter is wired directly to the batteries, red to red and black to black. In this configuration the converter will charge the batteries any time shore power is connected, regardless of the position of the disconnect switch. This is really a load disconnect switch. When it is in the OFF position there is no 12V power to the trailer systems. With an old, OEM charger, the converter will overcharge the batteries if the trailer is left plugged into shore power for extended periods of time when not in use. If your new converter is a three or four stage, this will not be a problem.

In the newer trailers, the disconnect switch is between the battery and the power panel, but the converter is wired to the power panel. In this case, the battery disconnect switch is just that, it disconnects the batteries from the trailer and the converter. The trailer 12V systems will have power whenever the shore power is connected, regardless of the position of the disconnect. If this is what you want, connect the converter red wire to the very top left screw called car battery, and the converter black either to the battery black screw at the bottom left or directly to the battery negative post. I will admit to being a little confused by the labeling of the car battery screw, indicating BLUE wire. Blue wire is normally brake.

Either way, don't forget to take power from your trailer battery and run it to your breakaway switch if that wiring is not already there.

Lastly, I see two potential problems in your pictures:

1. There is no battery negative cable connected. I'll presume you have it disconnected for this operation.

2. The battery positive cable looks like only a few strands go into the screw lug. If possible to get more in the hole, that end should be cut off and re-stripped to expose more strands.


Al

Hi Al,
Thank you so much for your advice. This is going to be at my home used as a "guest house" (I have a very small house). So we will not be using the battery. My dad was able to come help with the electrical today. Our tests showed that the 12v (lights and cig lighter) and the 120v (power outlets) work fine. I am hoping we did it right.

Again, I can't thank you enough for taking time to help. This website is awesome because of people like you!

[Lumatic]

Originally Posted by mailyohanPDX

Our tests showed that the 12v (lights and cig lighter) and the 120v (power outlets) work fine.

Danger Will Rogers, Danger! The 12v outlets are not cigarette lighters.

[mailyohanPDX]

Originally Posted by Lumatic

Danger Will Rogers, Danger! The 12v outlets are not cigarette lighters.

Oh no!

[Cochese]

I have a similar problem, this weekend while camping, I smelled a burning wire smell. I have a Progressive Dynamics 45 amp that is 3 1/2 years old. The battery went dead,but all 12v worked using generator. I also noticed the 30 amp automotive type fuse was blown on the negative side of block(65 overlander). When I got home, I had battery checked, it was bad. I removed converter, and it's putting out 13+ volts. My question is I had a large blue & large red in the positive & white in negative on converter! The red goes directly to the battery... what is it supposed to be hooked to?? Part of 12v doesn't work if not hooked to pos side of converter