[Bob]

The Techlink on your TV’s is showing you the house 12 and 24 volt systems which is where it should be .

The LCD screen is your Prevost Pro Driver which is showing your chassis battery voltage.

Did anyone do an orientation with you when you bought it?

Do you have the Prevost book and Marathon books?

Welcome to the Marathon Club.

Later

bv

[Archived]

The screen on your dash is what you should trust. It is getting a signal from the generator board through a small video box.

The generator board gets its signals from a shunt or donut shape device on your house 12volt and 24 volt cables. Go look at your house batteries which are in parallel and series and you’ll see these devices on the wall with cables passing through them.

[Marshall]

It’s not a matter of which one to trust it’s a matter of what source is giving the screen info.

I think Ed is referencing the LCD to the right of the steering wheel which shows Techlink functions.

The dashboard Pro Driver screen that is left of the steering wheel shows the Chassis battery voltage.

So Dave what screen are you looking at?

Later

bv

[John]

I am talking about the LCD display to the left of the steering wheel. It was showing 11.9 volts. I pushed the Jump Start button on the drivers left control panel and the reading showed it was charging up to 12.3 volts. I called Marathon Coach Tech Support and was told it was charging the chassis batteries from the inverter charger. He said it would not hurt anything to leave it on as it will go off when coach is started. After 2 hours the screen showed 12.9 volts. I think it should read in the 24 volt range. On the Tech link screen on the TV at first it was charging at 55 amps but 2 hours later it was down to 10 amps charge. I am going to get a 24 volt charger to mount by the engine. Does anybody have pics of how they mounted and wired a charger for the chassis batteries??

[Archived]

Dave,

As stated above:

The LCD display in the dash to the left side is measuring the battery system that is dedicated to start the engine and take care of the chassis side of your bus. To make it even more confusing, your Marathon has both a 12 and 24 volt system for the chassis or starting batteries. The display in the dash is showing you the 12 volt side of that system. Its a good indicator of your alternator system on the engine while underway. You should see that rise significantly when you start the coach.

The TechLink system shows you house battery health and status. if you are off shore power or generator power, you will see a battery voltage that is probably in the 12’s. Once you start your generator or start the engine of the bus, this voltage will rise due to the charging systems tied to gen power or bus power. Techlink also shows a 12 and 24 volt parameter.

Oh…and I heard you when you said Marathon said it was OK to leave on the battery bridging……..I personally would not do that. My understanding is that is only to be used if you have chassis battery issues and need a boost to start your coach. I don’t think that system was designed to be used that way.

Many coaches have a 24 volt charger that hooks to the chassis batteries and plugs in at the engine heat plug. Marathon modulates the power to that outlet depending on if the engine is running or not. (engine on….outlet off, engine off…..outlet on). Convenient place to plug in a charger for the chassis batteries. Many will argue you don’t really need a chassis battery charger. That’s for another time.

[Rick]

Dave

This is why I asked if you had the Marathon books.

Where you are confused is the Techlink screens do not show anything on the Prevost side. The pro driver screen showing 11.9 is chassis only forget about techlink for now.

I think you did not understand what the tech meant. In order for the jump start button to work you must have key in on position and hold jump start button for about 10 seconds and if you watch your gauge on pro driver it will go up to about 13.5 volts. Chassis batteries are being flooded by house batteries. As soon as you let go of the button it quits you have to depress to function.You will never see more than 14v on the chassis side.

Again all this is explained in your books. Remember Techlink shows only Marathon installed house items.

Pro driver shows Prevost side and you will learn how to differentiate the two.

Techlink is showing amps being pulled and ac coming in on shore or gen.

A lot of info in archive here about Marathon stuff. Who was the tech you spoke too?

My 07 which I had almost 10 years I never had a battery tender for the chassis. Back in that era of 04 thru about 2012 there wasn’t a good tender on the market so Marathon did not install any because guys were cooking the batteries with an overcharge. Now is different. You need to learn what is on the 12v prevost side that hampers killing your chassis batteries. 1 big offender is the basement lights which back then were all halogens which ate power, change to leds.

Later

bv

[Bill]

Click this link for Marathon Driver Monitor I am talking about:

/threaddetails.asp?Category=Electrical&ThreadID=12566

This monitor is the main monitor in my bus not yours for displaying Techlink information. Once again this screen displays the information from the waterbay board and generator bay board which collect data from various sensors around the bus including your house batteries. This is true for your bus as well as mine. Trust this screen…….. In the pictures in my link is what normal batteries that are fully charged should look like on screen.

Your Marathon bus should have two Vanner one for house and one for chassis. Check the readings at your Vanner for house side. One reading for 12 volt side and one reading for 24 volt side. The house Vanner is what is keeping your 12/24 system on the house side in balance or equalized. Anything above 13 volts at Vanner is good on 12 volt side. The 24 volt side should be double the 12 volt reading (26VDC). Readings below this are either bad batteries or bad Vanner…so test house batteries individually and if they test good a bad Vanner would be next in my book. The Vanner is pretty robust….. unit.

Post the picture of what your looking at in dash versus what your seeing on TV’s in cabin.

---

2005 XL Thompson Coach

Rarely tow anything behind us.

Sold: 1993 Liberty that we loved for 12 years.

[Jon]

I think I figured out the problem. I put a 12 volt charger on each different 12 volt bank and charged the batteries up full. Now the LCD screen on the left side of the steering wheel reads 12.9 volts with out the charger on. I ordered a Guest charger with 2 outputs and 5 amp charging. It will arrive Tuesday and be installed.

Thank you for all the advise

Dave

[DON]

(I think I figured out my problem.)

12.9 volts for chassis batteries at rest is a great number.

My conclusion is there is not a problem.

I’m out of here.

Later

bv

[Jon]

Well Done Dave, I like the easy solutions.