Chassis And House Battery Voltage

[greasecan]

Was wondering what the battery voltage should be with a Xantrex echo charger between the house and chassis batteries?

Reason I ask is that this morning in prep to leave here in a week, went to start coach and turned over some, now just clicks. Voltage on house is 13.6 and chassis is 11.5, checked with volt meter at battery.

It has been plugged in for 4 months and not run, (we are snowbirds). Tried the batt boost, but nothing happened except volt meter on dash went up. Put battery tender on (1.3amps) overnight, still no crank this AM. These batteries were new last June, Monday will remove and take to Interstate service center and have then load tested.

Even when new these NEW chassis batteries always had low volts 12.5/12.6. Beginning to suspect the echo charger is faulty.

Thanks for any help.

John M

2000 Safari 300 Cat

[wolfe10]

John,

Clearly, the Echo charger is not working. Check its connections and fuses. Once house battery is up to charge (usually 13.2+ DC) the Echo charger should maintain the chassis battery at the same voltage.

Brett

[greasecan]

I agree with you, Brett. The house and chassis should be nearly the same voltage. Checked fuses on Echo Charge and they were good, also checked to see if voltage was coming through the Echo Charger to the chassis Battery and there was voltage, but maybe not enought amps, chassis batteries have always been a lot lower in the 2 years I have had this coach, could explain some of my intermitten starting issues....

Have chassis batteries on a 12 amp charger now and they appear to be coming up.

Thanks John

2000 Safari cat 300

[wolfe10]

John,

The Echo charger is rated for 15 amps-- can't fathom that that is not enough to keep up ANY battery. Actually 2-3 amps is plenty as maintenance/float charge.

Have you verified that all battery connections are clean and tight, including the ground at chassis end?

Brett

[dickandlois]

John, Reading your post and Brett's response. Sounds like Brett's suggestion of checking all the connections in the starter area and the connections at the positive terminals at the Chassis batteries is in order.

The ground connections between the engine and frame should be clean and tight.

How old is the coach? The other thought is the starter brushes are causing a problem. You mentioned that it tried to turn over,that should eliminate the starter solenoid and relay.

When you tried to start after the first time and it tried to engage,has the starter circuit made any clicking sounds?

Even with the batteries in a weekend condition the starter circuit should react even if the engine does not turn over.

Should this be the case, then if you have a soft-blow hammer or even a block of wood to rap the starter a few times, even with someone turning the key might engage the starter.

They can start this way so work safe and do not jump to far if the engine starts.

Should it start,it tells me that the starter brushes and / or armature have issues. The starter will need to be rebuilt or replaced. This trick works a few times,but it will not start after a few times even with the banging.

Hope this helps! Rich.

[hermanmullins]

Check your voltage from the Positive Terminal to the chassis and not to the Negative Terminal. What you may have is a bad Ground.

[wolfe10]

Following Herman's thought process, if you check voltage from negative post of battery to clean chassis ground and find ANY voltage reading, you have resistance at the battery OR at the chassis ground end of the ground cable.

[greasecan]

Thanks all for the comments, at least it gives me something to go. I have the Batteries out now and my battery charger says they were fully charged this morning, now 12 hours later they are at 75-80 capacity. Taking batteries in to Interstate service center tomorrow, only 9 months old.

Never thought of measuring voltage from positive post to chassis ground.

I have beat on the starter before, so I think its time to change it out soon too.

Will post tomorrow when I get back..

John M 00 Safari 300 cat

[greasecan]

I took the batteries into the Interstate Service Center here in Lafayette,LA. They pronounced them OK, but low on charge, so on the charger they went at the service center. They have a much bigger charger than I do, so 2 hours later they were good to go. Installed back into the coach. Checked voltage before installed at the posts and again after from pos post to a metal frame support and was the same voltage, so that ruled out bad chassis ground. Still believe that old Heart Echo Charger is at fault. Did find out the propane detector and water pump are off of chassis batt. Don't think that's right.. Did find out the carbon monoxide detector works off the house battery. In dash radio works off of house battery, nothing else on dash does. Its late so will try to start her up tomorrow.

John M 00 Safari 300 cat

[greasecan]

OK, got it started this morning, but had to use a hammer on the starter, took more hits than usual. So I know I have a bad starter and will try to limp home.

I am going to fix it, but should I just rebuild the current one or just get another one?

What causes these CAT starters to act this way? only 42000 miles, but is 12 years old. Road splash?

John m

300 Cat

[wolfe10]

Before concluding that the starter is bad, put a voltmeter on it while someone tries to start it (do it safely with safety stands, etc).

If voltage drops below about 11.8 VDC while cranking, remedy that before concluding that the starter is bad. Yes, the starter could be bad, but low voltage will cause a lot of the same symptoms.

Hate to see you replace a starter is it is a loose or corroded connection or a bad battery.

[hermanmullins]

Check out your starter solenoid. When the solenoid activates it pulls the Bendix to engage it at the same time a brass plate is pulled to connect the positive cable and the starter cable. If you can pull the Starter solenoid without pulling the starter you can check to plate. Too many arcs and it becomes burnt. If your plate and contact bolts are arced clean them off (sometimes you can reverse the plate) reassemble and reinstall the solenoid and see if it will start. Doing this will allow you to check the starter before you have to replace it. The starter on my 400 ISL Cummins cost $528.00 to have tech. replace it.

Good luck.

[greasecan]

I am running out of time to troubleshoot, so went ahead and ordered a starter from Louisiana Cat. So removed the old one for core, while looking at it on the picnic table, noticed the Positive post on the solenoid had some arcing on the bolt, looks to me like it was never fully tightened down, even though the nut was extremely hard to remove (I had visions of it breaking or galling). Anyway its out and I'm going to replace it anyway.

I see why its important to check the connections, I don't think this would have been found as the nut was tight, galling on the threads I suppose and being such heavy cable, would be hard to wiggle next to the frame.

Thanks Brett and Herman for your input, I learned a lot.

By the way, that bolt was copper (soft)

John M

2000 Safari 300 Cat

[hermanmullins]

John, your welcome. The bolt is copper to make contact to the plate I told you about. Just for kicks and a learning experience take the solenoid apart and check there for arcing. It will help know what happens when you turn the key to start.

Let hope this will correct your problems.

Happy RVing.

[greasecan]

OK, got a reman starter installed, along with a new Xantrex echo charger, and it started right up, batteries are real close to voltage on house batt. House 13.78 and chassis 13. 56 so it seems I had a defective echo charger (org. with coach) and I did not realize the batteries were not getting charged.

Th new reman starter had a big yellow sticker on it warning of low voltage, anything less than 12.4v could be harmful to starter. We have devices to measure house batteries inside the coach, why not the chassis batteries also? May have to figure out something here.

Thanks for all the help.

John M

00 Safari Zanzibar 3886

300 Cat

[wolfe10]

John,

Surprised you don't have a dash gauge for chassis battery voltage.

Brett

[Briarhopper]

John,

First, my disclaimer. I'm not an expert, but only know what I have learned the last few years working on my hobbies (also known as motorhomes).

Have been considering adding an Echo Charge to our coach which made me interested in this topic. Reading thru the conversation it occurs to me your echo charge may have been working against an unknown current draw on the chassis battery. If there was voltage coming thru the echo charge and not charging would seem to indicate a bad connection or draw on the chassis batteries. Just thinking you may want to keep tabs on things.

Been a while since I played with starters, but it seems a bad solenoid could produce a drain on the batteries, which if so, you've already fixed.

My thinking may be completely off, but figured it might prevent a down the road disappointment if there was an unknown current draw that still exists .

Stuart

[greasecan]

I did find a damaged pos. lug on the starter solenoid, caused some arcing,could have contributated to the demise of the echo charge, but it was 12 years old and the new one is doing good with the volts in the middle 13's. Again this could have been caused by a bad starter connection

Brett, I do have a volt meter on the dash, will have to check it to see if it has higher volts now. I feel sheepish for not thinking of it.

John m

00 Safari

[pawoodtx]

On 3/25/2012 at 0:09 PM, hermanmullins said:

Check your voltage from the Positive Terminal to the chassis and not to the Negative Terminal. What you may have is a bad Ground.

I have a 2003 Monaco Windsor. I have installed a new carbon monoxide detector. I have 13 volts on the hot wire but the ground is bad. Does anyone know where that wire originates? I can’t find it or the hot wire origin.

Paul

 

[dickandlois]

Paul. A few questions?

Did the Detector just quit - no indication of an issue? 

Thinking it is installed in the bedroom area and mounted on an interior wall not an exterior wall. Mounted on the wall that divides the  bathroom from the bedroom or a closet wall ?

Any work done on the coach in the general area of the detector?

With a multimeter set on OHMS - do you get a resistance on any of the ranges between a known good ground and the detector ground wire ? 

 

Rich.

 

[hermanmullins]

Paul,

If your's is like mine the detector is mounted on the under side of a cabinet beside the bed. You may remove the bottom of the cabinet by prying up the carpeted bottom board. There you will find all of the wiring for you detector, both positive and ground. It may just be a loose ground.

Good luck,

Herman

[pawoodtx]

I bought the coach in November 2017. It hasn’t worked since I have had it. I can tell it was and issue before I got it. 

It is mounted underneath the cabinet fur down in the bedroom. 

No work done in the area since I’ve owned it. 

I’ll have to check for resistance. 

Thanks Paul

[pawoodtx]

43 minutes ago, hermanmullins said:

Paul,

If your's is like mine the detector is mounted on the under side of a cabinet beside the bed. You may remove the bottom of the cabinet by prying up the carpeted bottom board. There you will find all of the wiring for you detector, both positive and ground. It may just be a loose ground.

Good luck,

Herman

Herman thanks. I’ll go see if that is the same in mine. 

Paul

[pawoodtx]

Rich,

There is no resistance between a known good ground and the detector ground. 

Herman,

You weren’t kidding about prying!😱

I think both the hot and the ground are home runs.  I tested every position on the ground bar in the House battery compartment outside RR of coach. All were good. I think that wire is broken somewhere along the way.  What if I wire into the ground from the nearby light dimmer switch?🤷‍♂️

Thanks for your help,

Paul

[dickandlois]

Paul, If there is a good / solid ground and you can get to it, connect a wire from there to the detector and test things before pulling it in to where you want it to run. 

If something is going to cause an issue - it is better to find that using the selected ground is not going to work - before  finding out there is going to be an issue later. Make sure you operate the dimmer with the temporary ground test first.

Should things not work out as planned - you could use a circuit tone tester to fallow the current wire path of the OEM wire. 

A tone is placed on the wire and then you use a probe that can fallow the wire , by running it on the outside of the material hiding it.  I have always refereed to them as a Fox and Hound system. IT, Telephone and audio system techs use them to fine those allusive wires.

Rich.