I've finally got a day with decent weather and some time to work.
The plan is to raise the rear of the coach as far as it can go, then disconnect the negative terminal of one of the two house batteries. While I'm trying to figure out where those batteries are grounded, that one battery should be out of the charging circuit. If that battery has a problem, I should see a voltage drop in a couple of hours. If I don't see any voltage drop I'll put that one back into the circuit and disconnect the other one. In the meantime I still have one battery in the charging circuit and I can use lights, pump, etc. Does my thinking make sense?
David,
In reading your post, do you suspect you have a house battery that is not grounded? You could pull the positive terminal and then using a voltmeter, check the voltage at the battery post going to the chassis for a ground point.
Never a bad idea to run an extra short ground cable between the negative terminal and the closest frame location you can easily reach. Same with engine batteries.
Piece
Actually, I'm not sure what is going on. I'm thinking that maybe the house battery bank ground may be bad, or maybe one of the house batteries is bad. Since both house batteries are a year old I'm hoping that that isn't the case.
My idea is to isolate (disconnect) only one of the two house batteries at a time. That way I still have a battery into which the converter/charger is putting electrons and therefore I can still run the 12v stuff. Does this make sense?
Please tell me the negative cable from the house batteries doesn't end behind/underneath the starter!
A couple of people have suggested that I run a new ground cable from the batteries to a convenient grounding point. Would any convenient bolt on the engine or transmission be suitable for this? I'm sorely tempted to pick up a length of cable and some terminals tomorrow after church. There is a bolt that is just holding the pan on with nothing around it, and if that would work I'll use it.
Does each battery have a separate cable going from negative to ground?
David,
You definitely want a good large-gauge ground direct to the starter or very near it. You ALSO want a good ground to chassis clean metal and also to any other high amp device such as jack motor.
Electrons have to travel ROUND-TRIP to provide power, A good positive connection is NOT enough.
Said another way, can't have too many good grounds. Adding is fine. BUT, do not connect one to a bolt that will direct electrical power to an area where you don't want it. Not sure a pan bolt would be a good ground location.
Thanks, Brett. I'm looking for a good place to run another ground wire that is fairly close to the house batteries and is clear of moving parts and not in the way of something else that will eventually need attention. I understand that drilling into the frame is not a good idea, which is why I'm looking for an existing bolt that can be used.
I think I found a possible candidate. There is a bracket that holds one of the hydraulic oil reservoirs that has some extra holes in it. There is some paint on the bracket, but that can be removed easily. The bracket itself is attached to the frame. A 10' length of cable will reach very easily. My plan, unless someone has a better one, is to get 10' of battery cable and attach one end to the negative terminal of the lower battery. That terminal has only two wires on it, whereas the upper one has three. The other end will be attached to the bracket, and cable ties will be used to keep the new cable away from other things.
Brett makes several good points. While batteries need a good ground to the chassis, the engine must also be well grounded. I have seen several vehicles with good chassis grounds but broken or poor engine grounds. Agree, engine pan bolts might not be a good location. Many vehicles place a ground cable under the fastener that bolts the starter to the engine. This way, the engine battery ground is close to the starter.
I like to use welding cable and copper lugs with the proper sized hole for the bolt that goes through it. Then I strip the cable back and use a torch or gas stove to heat the copper lug and then using electrical solder, solder it on. You can slide shrink tubing on before you solder and then slide it down to cover the cable/lug joint and heat it so it shrinks and makes a nice clean installation.
Pierce
If your plan is to isolate a bad battery I would suggest that you buy a load tester. Disconnect all cables from each battery, test each battery separately and then you have a starting place. If battery is bad or charge on adjacent batteries is uneven then replace them and at the same time verify all connections.
Gary B
Hmmm, another tool. Might have to check that out tomorrow when I try to buy a cable and ends. Pierce, your plan is what I had in mind. Just thought of something - don't know if I have a propane torch yet or not. If not I'm sure that one of the other guys here has one.
Yes, I agree with Gary, load testing the batteries is really the only reliable way to check them. To properly test an 8D 1400 CCA RV battery requires a heavier load tester than you'll find at NAPA or O'Reillys. Here is the Auto Meter 800 amp tester. I'm not sure how long this sale will last, usually these are about $600 new.
Auto Meter 800 Amp Load Tester (http://www.mytoolsforyou.com/automotive-tools/ATM-SB5-2.html?gclid=CLyDp4SuksUCFZM9gQodD5YAPw)
I bought one of these on eBay for $75 and all it needed was a good cleaning. (The DW says I am obsessive/compulsive, I have 2 of these from eBay now - the second one needed new meters)
Several of you have mentioned adding large gauge wire as an extra ground. How large are you talking about?
I picked up some 3/0 and some 2/0 from Home Depot and Lowe's (end of the roll at 25% to 50% off). I also have some #2 that I used when adding a subpanel to install my 50 amp outlet.
Additionally, I have a lot 6/3 +G that I was going to use to rewire for the RV. Could I use the 6/3 as a thicker gauge by soldering all the wires at each end together? Oops, just realized that it might not be stranded wire ...?
I know, I know; I have the diploma, but that does not count for much in the practical application of wire gauges in an RV. :-[
Would some kind soul please help a veteran out here? :help:
Thanks,
Trent
Well I purchased this meter from the above web site and thought the advertised price was to good to be true. I was just notified my order was cancelled and I was given a full refund. :'(
We carry the Mac BT8300 Battery Tester, find it very dependable and displays the Battery CCA remainng capacity etc.. It is he same as the OTC tool listed on Amazon. No idea if it works on AGM or Gel types.
OTC Tools and Equipment shows to be National Tool Wearhouse on Amazon. They show the same Auto Meter 800 Amp Variable Load Carbon Pile Tester for $580.24.
NTX Tools & Tools For You appear to be operated by Coastal Tool Supply LLC. They are advertising the same Auto Meter 800 Amp Variable Load Carbon Pile Tester for $118.75. I was advised by Coastal Tool, through PayPal, that the order was cancelled due to a pricing issue. However both web pages are still advertising it at this price.
The OTC 3183 Is not accurate for AGM batteries. For AGM batteries, you will need the OTC 3167 Sabre HP. I found this out after buying the OTC 3183. I now have both, the OTC 3183 and the OTC 3167 Sabre HP.
OTC tools is owned by SPX and a part of Bosch Automotive Services Solutions Division.
Yea, I wondered about that ad. If you're not in a hurry, watch eBay. I have bought 2 that way. Repair parts are available from Auto Meter. I have a saved search with an alert for these. I promise to not bid on the next good deal! ;)
With a quick search I found this, looks like the meters are not broken, maybe he will take an offer:
800 Amp Load Tester (https://dallas.craigslist.org/mdf/tls/4964004331.html)
Here is a competitor - not sure of the quality compared to Auto Meter (probably made in China):
1000 Amp Load Tester (http://www.amazon.com/FJC-45118-Carbon-Battery-Tester/dp/B00KDI2LH4)
Hi Guys,
Harbor Freight sells a carbon pile load tester:
500 Amp Carbon Pile Load Tester (http://www.harborfreight.com/500-amp-carbon-pile-load-tester-91129.html)
I have one, it works quite well on my AG8Ds.
Jim
Jim, yes these 500 amp units are available for cheap (I have a 500 amp tester also.) But, to fully test a 1400 CCA 8D starting battery, you need to pull some heavy duty current and draw approx 700 amps continuously for 15 seconds. The 500 amp tester will tell you if you have a battery with a severely degraded cell and is capable of testing your alternator output under various loads.
I ordered one from them before I saw this post so I called them to see if they had my order. They said yes and it was going out today. I mentioned about the cancellation of someone who has already ordered. She said she had no idea why because they have many in stock. After I hung up she called back and apologized that her price is over $400. I said why do you not correct the website price and she said "IT" is slow and had something to do with Google. So she said I was not charged because it was not shipped. ::)
Looks like lot of negatives on Google about NTX.
USA Tool Wearhouse has the same price as Tools for You. Both of these companies appear to get their merchandise from Coastal Tool Supply LLC. At least that's where my PayPal refund came from. I have sent an email asking why the web pricing hasn't been changed and why have I not heard from someone in the company about the price discrepancy. My phone number and email address are on the order. If it wasn't for PayPal I would still be wondering. Reminds me of a car dealer pricing a car that they don't have to get you in the door. I wonder what else they have advertised that they won't sell.
Well I just received a rapid response from USA Tool Wearhouse. I'm impressed. Also Tools for You has changed their price on their web site to $510.03
Dick,
The price has been changed, We made a mistake and had to cancel the order. Your were set for a phone call by days end today. Sometimes mistakes are made and we have to act fast to protect the customer to make sure they get their money in a timely manor. While I would love to be able to call everyone right away. We are busy today and wanted to make sure you saw refund and then would get a call with explaintion later today
Thank you for your understanding
Regards
Allen Dimick
Dick,
Proves the old adages: "Perseverance Pays Off" and "The Squeaky Wheel Gets The Grease". (Sorry you didn't get the "bargain" tester.)
I bought 10' of battery cable and connected one end to the negative terminal of the lower battery and the other end to a freshly cleaned bracket that is attached to the frame. The negative terminal I used had three cables on it, while the other one already had four. One of those connections, of course, connects the two batteries to each other. I could have gotten away with less cable, but I wanted to have enough in case I need to try another connection point.
I tried cranking the generator. As before, all I got was a lot of clicking. The lights in the coach were blinking in time to the clicking. I can see the generator trying to turn. Also as before, a few minutes after I came in the house lights dimmed and the Kool-O-Matic fan slowed down. A few seconds later all was back to normal. All of this was done while connected to 50A service.
Conclusions so far: All connections that I can see seem to be fine. I'm quite certain that I have a good ground for the house batteries. The batteries themselves seem to be fine.
Further questions and tests: Friday I'm going to shut down all the 120V stuff (computer, tv) and flip the breaker. IF the interior lights stay on I'll try starting the generator. I'm pretty sure it won't start, but if the lights stay on then I'll know the batteries are good.
As I was writing this Jo Ann and I tried to remember when the last time the generator worked. We're pretty sure it was working when we headed to Pevely in October and wasn't working when we left there on 1 December. Question: is it possible that the generator starter is the culprit? It is turning the engine, but not fast enough to fire.
David,
Open the generator door, bring a car next to it and use jumpers to directly supply the generator to start it. If it won't start right up, it's the starter.
You can also use a small container of diesel and a return line back to it to find air leaks, and diagnose any fuel problems the generator has. Installing a low pressure gauge really helps too. Less than $20 buys enough hose and a pressure gauge. See my old posts for photos of the generator fuel pressure gauge along with the added coolant temp gauge.
Pierce
This afternoon I shut off the a/c units, the computer, etc. and then flipped the 50A breaker to off. I left the interior lights on, and checked that they were still on as I measured the battery voltages for both house batteries. Both were pretty close to 12.8. I then went to the generator, turned on the preheat, and watched the interior lights. They stayed on. As soon as I hit the start, though, I got one click and all the lights went out. I checked the battery voltages and found about 12.6 on each one.
Does this start to sound like battery problems?
It still could be the starter. Load test your batteries or substitute a known good one as Pierce suggested.
Sounds like something is causing a dead short. Starter locked up, grounded cable somewhere, Locked starter solenoid. Use known good battery and jumper cables direct to starter, if same thing then you know its starter, if not its somewhere else. Or jump terminals at starter to see if it will start . That will also eliminate starter.
Gary B
David, When 12-volt batteries are connected together (parallel) both will read the same voltage, even if one of the batteries are dead, so there is no value in check voltage on both house batteries.
I would put my money on a poor positive or negative cable connection somewhere. But a damaged generator starter may act the same. It would help if you knew the battery voltage at the moment when the generator starter is trying to run.
Does starter work ok when boost switch is on?
The generator has not been able to start since sometime in the fall. Using the boost switch, plugged in, Detroit running, doesn't make any difference.
What started this whole thing was that we had no 12v power from the coach batteries while underway. Scuba Guy tried to help me with it when we were at St. Peters, MO in November. We're going to be quite busy this weekend, but maybe Monday afternoon I can get Jo Ann to try to start the generator while I watch the VOM.
BTW, I've separated the batteries and checked the voltage individually several times, and they are always showing good. I'm a bit concerned about today's readings, though, as these are the lowest I've seen. The Audit system is showing 12.7 vdc right now, and that may be right, but since it is wrong on all of the tank readings I'm not sure I trust it on this, either.
As an aside to this, is there a suggestion of someone who can check this electrical issue out in RIVERTON, WY? I specify Riverton because we will be there for a couple of weeks for our daughter's wedding. We'll be staying at the campground in town.
I may have mislead some of you here when I described the "starting" of the generator as a clicking sound. It is more like a metallic banging. I think I'll try to record it this evening on my iPhone and then see if I can attach that recording to the report of what the battery voltage is at the moment of cranking the generator.
With all of this preparation to report on the misbehavior the generator will most likely fire right up.
We checked the battery voltage as I cranked the generator. Voltage was 13.07 initially, dropping to 12.99 as I had the preheat on. There was NO change when I cranked the generator.
I recorded the generator's sounds as it cranked. Unfortunately, the iPhone stores that sort of file as an m4a file, which is not allowed on this forum. If someone has an idea of how to post that file please let me know.
On edit: the audio file is attached (I hope).
The forum shows m4a filetypes are acceptable.
We recently changed m4a to mp3 using the Internet.
M4A to MP3 | Zamzar - Free online file conversion (http://www.zamzar.com/convert/m4a-to-mp3/)
Not an expert here, sounds like a clickING contact switch at first, then the clank, clank.... like like you SAID METAL TO METAL" , may be the starter solenoid not enguaginge the gears against the flywheel .. but grinding... DON KEEP TURNING IT OVER. I say this because of you battery voltage.. and it turns... may use a percussion instrument on the case of the starter.. tap, tap... A couple of times.. which is what i did on my 88..others are way more experienced, if it were mine... it's mechanic time ^.^d
SOUND worked fine
I also think it sounds like a solenoid trying to make contact. Did not hear any cranking sounds just the 2 clicking ones.
JohnH
David:
That is the classic sound of a starter solenoid with low voltage. The solenoid tries to connect the starter, but as soon as the starter draws current, the voltage drops, causing the solenoid to release, repeat...
Need to find where the voltage drop is occurring. I would start at the house battery with a voltmeter, have someone try to crank the generator, measure voltage at points along the wiring path to the generator.
In your post you mentioned measuring voltage, and it didn't drop much - where did you measure it?
Continued:
I dug out my 12V schematic which I don't think is much different than yours. The main wire from the house batteries connects to the inverter fuse, then the boost relay, then the battery charger fuse, then runs to the main house battery switch by the entry door (aka the salesman switch), then finally runs to the generator starter. At any of these terminations there is a terminal lug and a nut, and the opportunity for a bad connection. Note the inverter fuse, boost relay and charger fuse connections will be under (inside) your 12V cover panel. The salesman switch should be accessible inside one of your cargo doors by the entry door.
Thanks, Peter. I checked the battery voltage at the battery terminals. Are the "inverter fuse" and "battery charger fuse" the two automatically-resetting circuit breakers? We're in for several days of rain, so playing with electricity isn't high on my to-do list, but if I can have a few hours this weekend without rain I may be willing to shut everything off and try tightening connections. Again.
I spent some time today poking around here, but I'm not sure what I actually accomplished. I turned off the 50A service, but left the batteries connected. I checked the battery voltage, and got around 12.6 or a bit higher. I then checked voltage at various places following Peter's suggestions. There are two automatically resetting circuit breakers and one that is reset by a push button from the rear. I got the same voltage on that manual one as I had on the batteries. Everywhere else I checked was about one volt lower. One nut on the salesman's switch was not as tight as the other one (it is now), but otherwise all connections were tight and clean. I then tried starting the generator, but stopped immediately as all I got was the same sound on the recording above.
At this point I'm thinking that the starter has a problem. We'll be leaving Stillwater on the 26th, heading for Riverton, WY. Any suggestions for a repair shop in the Riverton area?
David,
You need to find and correct that 1 VDC "loss". That is HUGE.
I agree, Brett. That has me puzzled. I don't know if I'll be able to do much with it this week, but if I get a chance I'll see what I can see. I may have to wait until I get to Riverton. Jo Ann and Karen are planning a couple of shopping days, so I'll have time to work.
Get a long piece of wire (like an old extension cord) and run it back to negative post on your battery when you check. Many electrical problems and headaches are caused by ground issues.
I added an additional ground cable a week or two ago. Thanks for reminding me about it, though, as I will need to make sure it is safely tied up before we take off for Wyoming.
There is a negative connection in that 12V box, so maybe the next time I poke around there I'll try running a wire from that terminal to the negative battery terminal and then see if that changes the voltage readings.
I took the coach in this morning to have the generator worked on. About two hours after I dropped the coach off I got a call that it was done. It turned out that there was a poor connection somewhere. I ran the generator from the shop back to the campground and all was well. We'll see how it works Tuesday, when we head east for the next event on our busy summer schedule.
That's great news! :))