Community Forums

BPoland · 06-18-2016, 07:07 PM

I bought the lighted dash switch from Newmar. I installed the switch in line on the main power supply to the radio. Also supplied a ground connection for the lighted part of the switch. To double check my work. I broke out my multi meter. On the power in side of the switch, I read 13v. Just what I expected. Turning the switch off, I still received,5.2v from the terminal going from the switch to the radio. To make sure it wasn't some kind of bleed over from the switch, I disconnected the the wire in question from the switch. With only the. 12v memory lead connected, I still read 5.2v on the red power lead out of the radio. I did not expect to read any voltage on that lead. Since the radio was turned off at the time. Am I missing something or is it normal to get some backfeed from the memory circuit?

dpinvidic · 06-18-2016, 07:15 PM

Not surprising. The memory circuits do no need full voltage to retain their contents, but they do need full voltage to read/write.
Sind the memory power and main power must join together in the radio, it is very likely that this is normal for that (or most) radios.

Regards,

Dan

Skip426 · 06-18-2016, 07:27 PM

I chased a power problem with the dash lighter socket . Showed power with the volt meter but wouldn't run anything when the plug was used . After some hair pulling , turned out to be cross feed from the solar panel , removing the 5 amp solar panel fuse dropped the lighter volts to zero and then I found the blown fuse.
That was my problem , now on to yours. The radio, if it has a power disconnect memory , will not have a battery , but a charge capacitor , that would bleed down over time. You could try leaving the radio disconnected for 48 hrs to see if the volts drop. Remember a volt meter only needs milli-amps for a reading .
So the power for/from the memory circuitry may not be that much ; or anything to worry about for that matter.
If your still worried , please post the radio info , brand and model.

BPoland · 06-18-2016, 07:51 PM

Quote:

Originally Posted by Skip426

I chased a power problem with the dash lighter socket . Showed power with the volt meter but wouldn't run anything when the plug was used . After some hair pulling , turned out to be cross feed from the solar panel , removing the 5 amp solar panel fuse dropped the lighter volts to zero and then I found the blown fuse.
That was my problem , now on to yours. The radio, if it has a power disconnect memory , will not have a battery , but a charge capacitor , that would bleed down over time. You could try leaving the radio disconnected for 48 hrs to see if the volts drop. Remember a volt meter only needs milli-amps for a reading .
So the power for/from the memory circuitry may not be that much ; or anything to worry about for that matter.
If your still worried , please post the radio info , brand and model.

The radio is the Dual X2DMA400 that Newmar installed in 2014 Bay Stars. It has 2 power supplies. A yellow wire for memory and presets and a red wire for the main power supply. I installed the new switch on the main power supply wire. I have been trying to eliminate any parasitic draws on both the chassis and house batteries. I have replaced all the batteries in the last year, but the chassis battery voltage level will drop significantly over 3 days. Last on my list is an antenna booster for the TST TPMS system that I installed in the back wardrobe closet. It is currently on all the time. I plan to install a switch so that I can turn it off when it isn't needed.

Skip426 · 06-18-2016, 08:25 PM

Three days is a significant draw , usual from the engine and trans ECM's would be 3 weeks to drop volts to a questionable start situation.

dpinvidic · 06-21-2016, 03:48 PM

Quote:

Originally Posted by BPoland

The radio is the Dual X2DMA400 that Newmar installed in 2014 Bay Stars. It has 2 power supplies. A yellow wire for memory and presets and a red wire for the main power supply. I installed the new switch on the main power supply wire. I have been trying to eliminate any parasitic draws on both the chassis and house batteries. I have replaced all the batteries in the last year, but the chassis battery voltage level will drop significantly over 3 days. Last on my list is an antenna booster for the TST TPMS system that I installed in the back wardrobe closet. It is currently on all the time. I plan to install a switch so that I can turn it off when it isn't needed.

Bill,

What are you doing over these three days, boondocking or storage?
Many inverters are connected directly to the house batteries. Even with the battery disconnect switch off (or the inverter off), the draw on mine is almost 2 amps because it also has a remote panel.

Regards,

Dan

BPoland · 06-21-2016, 06:03 PM

Quote:

Originally Posted by dpinvidic

Bill,

What are you doing over these three days, boondocking or storage?
Many inverters are connected directly to the house batteries. Even with the battery disconnect switch off (or the inverter off), the draw on mine is almost 2 amps because it also has a remote panel.

Regards,

Dan

That's 3 days in storage. I have heard that the radio, since both the memory wire and the main power lead are connected to unswiched power, that could be drawing them down. Also, I know the TPMS antenna booster in the rear wardrobe closet is on all the time. I will be installing a storage cut off switch on that as well. It seems that most of the parasitic draws that I have found, are on the house batteries. Once I get rid of all the parasitic draws that I can find, I will recheck the batteries' condition.

dpinvidic · 06-21-2016, 07:42 PM

Bill, dont you have battery disconnet switches?
If not, why not install them. It is the same as removing the batteries and putting ghem on a shelf.

Regards,

Dan

BPoland · 06-22-2016, 08:02 AM

Quote:

Originally Posted by dpinvidic

Bill, dont you have battery disconnet switches?
If not, why not install them. It is the same as removing the batteries and putting ghem on a shelf.

Regards,

Dan

The coach has a battery disconnect switch that will kill most of the draws. I keep the coach plugged into 20 amp service in storage, or at least it's supposed to be. I have twice gone over and found my coach unplugged, because the needed the power for a coach that was going out in the next day or so. They had forgotten to plug mine back in. On another occasion, although my coach was plugged in, my Progressive EMS was blocking the power due to low voltage. They have worked to solve all the issues and my coach is now parked in the back of the warehouse on a dedicated power line. The point is, in both of those occasions, my batteries were drained significantly, from full charge. It is my understanding that if I engage the battery disconnect switch, the batteries will not receive a charge either.

My goal has been to eliminate as many of the parasitic draws as I can.