12v Accessory socket issue

How much power does the meter show? If the is no fuse, or the fuse is oversized you might have burned up the wire and only a few strands are left. This is enough to read 12 volts on a meter, but not carry any load. I would pull the outlet back out of the dash and check the connections for heat damage.

Actually thinking about it, I'll bet the fuse partially blew so they all still look good. Plug something in with an LED, and pull fuses until the LED goes out. Then replace that fuse.

opnspaces wrote:
How much power does the meter show? If the is no fuse, or the fuse is oversized you might have burned up the wire and only a few strands are left. This is enough to read 12 volts on a meter, but not carry any load. I would pull the outlet back out of the dash and check the connections for heat damage.

Actually thinking about it, I'll bet the fuse partially blew so they all still look good. Plug something in with an LED, and pull fuses until the LED goes out. Then replace that fuse.

Hi there. Yes, 12.5 V on each socket. But as you say, somehow not enough power. I was thinking about a partially blown fuse as well. Unfortunately, there is no fuse marked for 12 V outlets, strangely enough.

opnspaces wrote:
How much power does the meter show? If the is no fuse, or the fuse is oversized you might have burned up the wire and only a few strands are left. This is enough to read 12 volts on a meter, but not carry any load. I would pull the outlet back out of the dash and check the connections for heat damage.

Actually thinking about it, I'll bet the fuse partially blew so they all still look good. Plug something in with an LED, and pull fuses until the LED goes out. Then replace that fuse.

Alright, finally found the fuse (it looked okay), replaced it, and still not enough power. The wires also appear to be fine. Now what?

There are two types of fuses and panels. One (of each) has a light inside to indicate fuse blown (Progressive Dynamics panels have an LED beside the fuse and some fuses it's built in either an LED with bridge recrtifier or 2 led's or a small "Grain of wheat" lamp)

This will pass power.. oh a few mA but not enough to use.

Plug in your load (a map light is good) and look for the blown fuse.

Also look at the ground lug.

For this problem a meter may be the wrong tool to use. What you really need is to buy or make a 12 volt test light. Harbor Freight has one for $3. Link

With a test light you can measure how much power can be passed down the wire via the brightness of the bulb. It's not an exact measurement like a meter, but it will work for what you need. The problem with a meter is like wa8yxm says. A simple LED indicator on the fuse panel will pass 12 volts to be read by a meter. But it won't pass enough current to run anything.

If you look at a 12 volt fuse you will see two small holes or slots on the back of the fuse next to the number. These holes are the back side of the fuse blades and let you poke a probe into them and measure voltage without unplugging the fuse. You can poke the positive from the test light into each hole and connect the negative clamp to a ground and see if the light lights. It should be the same brightness on each slot. While you're at it poke into every fuse in the box and see what happens.

If all the fuses test good start working down the line to every connection you can find between the fuse and the sockets until the light stops lighting.

Last thing, always start any check, whether with a meter or a test light at the power source (the battery in this case). You need to know what the battery reads or how bright the light is, or even if the light works, before performing any interior tests.

Bobalooie wrote:

opnspaces wrote:
How much power does the meter show? If the is no fuse, or the fuse is oversized you might have burned up the wire and only a few strands are left. This is enough to read 12 volts on a meter, but not carry any load. I would pull the outlet back out of the dash and check the connections for heat damage.

Actually thinking about it, I'll bet the fuse partially blew so they all still look good. Plug something in with an LED, and pull fuses until the LED goes out. Then replace that fuse.

Alright, finally found the fuse (it looked okay), replaced it, and still not enough power. The wires also appear to be fine. Now what?

How do you know this is the fuse for those outlets? Newmar had 2 places for the fuse for the dash outlets.
1. The outside Shore Cord compartment has a fuse block and fuses in that compartment
2. The Main outlet up front in the front hood access/ Your model I think had the large clear Plexiglas covered electrical box.
When your type problem happens(shows 12 volts but cannot transmit a load) most of the time it is a partially blown ATC fuse. Not totally blown. Just a small sliver still making contac. Putting a heavier load(at least 10 amps) will melt that small sliver and then show the blown fuse.
At this point, IF you are positive you have 12 volts pos at the outlet, run a separate ground to the ground of the outlet and see if your problem goes away. If so, run a new ground to those 2 outlets. Doug

dougrainer wrote:

Bobalooie wrote:

opnspaces wrote:
How much power does the meter show? If the is no fuse, or the fuse is oversized you might have burned up the wire and only a few strands are left. This is enough to read 12 volts on a meter, but not carry any load. I would pull the outlet back out of the dash and check the connections for heat damage.

Actually thinking about it, I'll bet the fuse partially blew so they all still look good. Plug something in with an LED, and pull fuses until the LED goes out. Then replace that fuse.

Alright, finally found the fuse (it looked okay), replaced it, and still not enough power. The wires also appear to be fine. Now what?

How do you know this is the fuse for those outlets? Newmar had 2 places for the fuse for the dash outlets.
1. The outside Shore Cord compartment has a fuse block and fuses in that compartment
2. The Main outlet up front in the front hood access/ Your model I think had the large clear Plexiglas covered electrical box.
When your type problem happens(shows 12 volts but cannot transmit a load) most of the time it is a partially blown ATC fuse. Not totally blown. Just a small sliver still making contac. Putting a heavier load(at least 10 amps) will melt that small sliver and then show the blown fuse.
At this point, IF you are positive you have 12 volts pos at the outlet, run a separate ground to the ground of the outlet and see if your problem goes away. If so, run a new ground to those 2 outlets. Doug

I put a 12v bulb in the socket and when I pulled the fuse (in the front compartment), the power was cut. I replaced the fuse to make sure. Are you saying there are two ATC fuses for the sockets?

Definitely have 12v at the sockets. So weird.

I can not tell you about your RV but on mine it came with TWO (now has several) 12 volt sockets
One on the dash was a "Chassis" device. the chassis has 2.5 Fuse boxes and I do not know which one feeds it.

The other one (down by the co-pilot's right foot) is a HOUSE device.. and recall the LED indicator fuse panel I said Progressive Dynamics makes.. Well I have one.

SOLVED.

I got Newmar on the phone and they led me to a hidden fuse panel on the dash under a velcro panel. F28 is the fuse for these sockets (the fuse I found must be a secondary fuse of some sort because it is also connected).

I replaced the fuse and all is well. Thanks to everyone for your help.