Community Forums

azSkier · 10-13-2015, 11:43 PM

Anybody know where these connections are?

I suspect I am having electrical issues with the 12V system and I want to clean these connections. I have looked at the battery bank and can see 3 large cables; one of which goes to the inverter.

The other 2 I am not sure. They probably attach to the frame. But where?

Also, the 12V fuse block in the bathroom has a ground. A smaller wire, probably 6ga or so. I really want to find the other end of that cable as it is my prime suspect.

The issue I am investigating is a voltage difference between the fuse block and the inverter. With no loads, they will have the same voltage (12.9). As I turn lights on, the voltage at the fuse block will drop (12.7). As I turn on more lights, the voltage drops even more (12.5). When I turn off all the lights, the voltage returns to 12.9. (0 difference).

All this time, the inverter voltage remains constant... suggesting to me the batteries are fine.

"007" · 10-14-2015, 07:38 AM

Most times they will be as close to battery locations as possible its tight quarters under their and some what difficult to see or even work on.
You may need some one to pull cable near batteries while your looking under coach.
There are some threads with pictures that may point you to location in QT's # 3 try some of the Mod section of the people you will see in their section.

tom chelbana · 10-15-2015, 07:57 AM

We have an 04 Essex and this would be normal to see small voltage drop when you start turning 12 volt items on. Newmar does a good job of using 10 gauge wire for most 12 volt systems and this would be normal in almost all case to see small voltage drop as items are turned on. Don't think you have a problem.

azSkier · 10-15-2015, 10:34 AM

Tom - thanks for your sharing your opinion.

However, I am stuck with the following thought... if 20-30 LED lights can drop my voltage at the fuse panel by .6V, then imagine what my slide motors are doing.

I am heading out for a weekend trip and will be investigating this issue fully. It looks like newmar is using 2 8-guage cables as ground wires as ground cables. There should be no voltage drop with clean connections. I will be measuring my ground resistance later this afternoon.

I still need to find out where these cables attach to ground. I have traced the large cables from the battery going forward of the drive axle. I have also traced the grounds from the fuse panel down into the power bay and then into the wet bay.

tom chelbana · 10-15-2015, 04:05 PM

Have you done a load test of each battery? Shouldn't have more then a 1 volt drop in voltage in the 30 sec. of the test with 50 AMP load. Do you think you might have a battery concern? Replace our batteries sometime between 3 to 4 years.

azSkier · 10-15-2015, 04:59 PM

Quote:

Originally Posted by tom chelbana

Have you done a load test of each battery? Shouldn't have more then a 1 volt drop in voltage in the 30 sec. of the test with 50 AMP load. Do you think you might have a battery concern? Replace our batteries sometime between 3 to 4 years.

The batteries are 2 yr old AGMs. At my coach's recent physical, the batteries were tested and no problems were reported.

As I somewhat described in my original post, I have 2 points of battery voltage monitoring; the inverter and the seelevel panel attached to the fuse panel. With no loads, both report the same number. As I increase the load, the inverter value does not change while the fuse panel drops.

Since the inverter voltage is directly tied to the battery(no AC, so no charging) and the inverter voltage is constant, I feel the batteries are not suspect in this test.

Tough choice for me right now... I just got setup in camp and I can relax and have a beer or I can chase battery gremlins. What to do, what to do!

bruceisla · 07-08-2018, 03:50 AM

Did you ever find all the ground connections? And, if so, where are they?

rewillia · 07-08-2018, 05:19 AM

There are numerous chassis grounds, i.e. battery storage compartment, front generator slide compartment (where the Chassis management system grounds), rear engine service bay, etc.

azSkier · 07-08-2018, 07:40 AM

No, I did not. Newmar tech said they are near the inverter/power bay. I have not found the termination of the big ground cable from the battery. The only place I have not looked is inside the tank bay. The connection could be above the black tank.

As for my electrical gremlins, I have them under control by having really clean terminal connections for each battery post. I have used sand paper to clean every surface of every part (cables, post, washer, bolt). Lots of shiny copper.

bruceisla · 07-08-2018, 07:54 AM

Quote:

Originally Posted by azSkier

No, I did not. Newmar tech said they are near the inverter/power bay. I have not found the termination of the big ground cable from the battery. The only place I have not looked is inside the tank bay. The connection could be above the black tank.

As for my electrical gremlins, I have them under control by having really clean terminal connections for each battery post. I have used sand paper to clean every surface of every part (cables, post, washer, bolt). Lots of shiny copper.

I have found a few.

1) Behind the starter ... stud in engine block (visible from underneath) ... multiple wires.

2) Inner side of frame .... alongside starter .... stud in frame .... multiple wires (visible from directly below starter).

The quest continues

azSkier · 07-08-2018, 08:07 AM

Multiple wires? I have been looking for the termination of the large 00 cable.

Winepress · 07-08-2018, 08:19 AM

Make sure if you pull the inverter ground that you pull the positive first and the inverter is off.

"007" · 07-08-2018, 08:35 AM

Grounds are always of interest to people, its not something we just stand on, I chased down some some years ago and posted in the TECH Information link and have added a few for ESSEX Owners in their thread for screen locations on Silverleaf and possible the E-Plex system.
If you have the 00 cable to follow make sure you keep following to the chassis frame after going through the cut off switch, for negative side, to disconnect your chassis batteries.
The inverter or the converter will have a #6 ground cable also, your steps will have three ground cables just for a few.
Yes and reading through the QT's #3 link may lead to o some others when you have a problem to solve.
Never know what you may find in this link every Newmar should have.

bruceisla · 07-08-2018, 08:35 AM

Quote:

Originally Posted by azSkier

Multiple wires? I have been looking for the termination of the large 00 cable.

I don't mean to hijack but ....

The problem I'm chasing is: "sometimes" I get a "slow start" (insufficient cranking speed for the ISM 500). Bats are 1 year old, bat cables are clean and tight, ran a separate large jumper from the negative side of chassis bats directly to the ISM block .... still slow crank. Pretty sure I have the infamous slow rpm Delco starter issue. New Denso R5 reduction drive starter is arriving next Friday. I'll clean the mentioned grounds when I have the starter out of the way and see if I can trace the "big" ground. FWIW, at least one of the wires I mentioned is fat (not sure of gauge without pulling the starter for a close look).