this will be a long post. i am also willing to admit i am not as good as i thought i was on this. so you will find at the end i found out what was wrong, but think you might learn something from my blunders along the way.
the last few times i used the coach, it acted like the engine batteries were real weak. it would just click. when merge switch was on, it would turn over faster and may start or not. i would charge everything for days and same results.
so i started on my qwest to figure out why. i checked the voltage across each battery and they were all 13.6 volts. my engine batteries were interstate workhorse and were 4.5 years old. here in arizona, batteries just dont last that long, so i took them out and at SAM's club had them checked. i was sure they would have a bad cell or two, but they load checked good. since they were so old and soon to fail, i went ahead and bought two new 8D batteries at sams club. their house brand is Powerfast and they are made by interstate. they actually have a higher CCA than the interstate workaholic. 125 bucks each, good deal. i put them in and as i climbed into the cockpit with confidence, no go. same thing.
i had never changed the merge solenoid, so i was getting some funky readings on it so i changed it. walla, no difference. i would get voltage across both terminals.
my merge switch was acting funny and i spent hours tracing out the merge wiring. it would only merge off of the house batteries and not the engine batteries.
i cleaned all the battery cables i could get at and checked for corrision and they appeared just fine.
so, i put a clampon amp meter on the starter positive cable right at the starter. it would peak at 1300 amps and float at 600 and under. so when i told the starter place that rebuilt my alternator last year that he said that was probably too much.
so i took the starter out. easier said than done. use the air to lift the coach as much as i can, use 2 20 ton bottle jacks to hold it up and off i go.
first take the screen off that covers the entire bottom of the engine. then disconnect all the batteries and use the dissconnect switch. take the cables off the starter. then i attached a strap around the starter, had my 17 year old daughter hold it up top as much as she could and i took the bolts off. they were really in there an i had to use a rubber mallet on an box end wrench (no socket can get in there) to get them loose. then an makeshift ratchet box end wrench with a piece of pipe on it to get the top bolt off.
btw, the starter weighs about 80 pounds or a little more. it is huge. she held the strap and i jockeyed the starter around some oil lines. she then slowly lowered the starte as i held it overhead while on a creeper. it weighs almost as much as she does...
i set it on my chest to catch my breath and that didnt work very well. it really took my breath away as it sat there. i quickly got it to the ground.
i quickly put it in my car and drove looking like a dirty bigfoot to the shop that was 25 miles away in far west phoenix. i got to this great little shop and they stayed open for me as i got there after 5pm. they bench checked it with no load and it was ok. he said that it likely was worn and would fail under load. so he made me a great deal on a rebuilt starter with a one year warranty and figured i would just get it and put it in. if nothing else another thing not to fail. it was the original starter. 250 bucks for the starter.
while i was up there that far i popped over to suprise arizona and saw my grandkids...
the next day i installed the starter. put it on a floor jack, tied two straps to it and had a burley buddy up top and me down below. i am doubly burley at 6'2" and 300 pounds...i got it installed in about 15 minutes..but it is really heavy and you could easily crush yourself without help.
now i am really confident...i go to start it and nothing. exactly the same. i got it started on merge, but not on engine batteries only.
so, i tear the back stainless panel that covers the disconnect switches etc out and trace all battery cables around and take them off and clean them. i started ohming each one out to make sure it would get down to as close to zero ohms as possible. they were ok. but, i had an open between the ground cable for the engine batteries where it mounts to the frame and the negative of the last engine battery.
now here is where i feel dumb. the big brass looking round 600amp fuse that is bolted on the battery on the ground of the first battery was blown. no indications other than it was totally open. the reason i didnt catch this is i checked the voltage on each battery a number of times by just checking across the positive and negative of each battery and of course they said good. i never went from positive to coach ground....then i would have know there was no ground.
here is another strategic mistake i made. i would turn the engine batteries off and stil measure voltage at places it should have been the engine batts. what i had neglected to do was turn the coach charger off that was plugged into the house. it must send juice all over the place. so i was getting bogus readings.
so, for the last few months i was only starting it from the house batteries and i suspect they really are getting weak as they are standard workaholic batteries that have been charged and discharged a bunch of times. i took the fuse off of that one and put it on the starting batteries and it started right up easily....duh......
so i ordered off of ebay a couple of those fuses. they sell for 90 bucks at grainger and i got 2 of them for that price on ebay.
so, i have batteries that are new that i would have done soon anyway, a new starter that shouldnt fail for the life of me and the coach, and now the merge works the way it should....
so, i dont know what caused the fuse to blow. i am assumming that perhaps when i changed the alternator i must have done something...or when the regulator on the old alternator shorted out.
so, lesson learned until the next time i blunder around. maybe you guys can learn from it as well.
at least my labor is cheap......and i understand alot more about how things are wired...
Wow, Tom.....I know exactly how you feel. I've lost track of how many times an electrical problem on one of my vehicles has been a "ground" issue, and yet I seem to always assume the worst when trying to track down an electrical problem. Again, as others have said so often, THANK YOU for sharing your experiences so thoroughly. I have learned a lot from reading your posts!
I tried to start my coach today, and it wouldn't start. I tested the batteries with a volt meter: one tested at 13.8 volts and the other one at 2.4 volts. I tested them with the coach plugged in and with all of the cables connected. I put the volt meter test leads on each battery post.
It looks to me like I have a dead battery. The starting batteries are 4 years old.
I would recommend a load test. The tester will put a load on the battery as it tests it. You can check the alternator with it as well. Anybody who sells batterys should have one..Maybe you can borrow it?? I finally bought one(snap-on) on ebay for 30-40 bucks. Maybe if you had somebody try to "turn it over" while you hold the voltage tester on it?
1993 Newell 45'#316, 1976 Trans Am 455, 1967 GTO, 1953 Chevrolet 3105 (panel truck),1952 Chevrolet 3600,1969 Airstream Overlander. Always fixing something!
dean is correct, and that is what i meant by "under load". when the batteries are working properly you should only see a 1-2v drop when you are starting the engine. the same would be with using a load tester.
the question i have is will the cheaper load testers put enough load on an 8D battery?
are they agm or flooded cell batteries? i personally wouldnt waste the money on agm starting batteries.
it doesnt hurt to equalize them. your charger will do it.
load testing is going to be the real key, whether by starting the coach or having the batteries tested. i replaced all of my batteries. they are really heavy......
They are 8D wet cell batteries, not AGM gels. I tested each cell after charging them for about 2 hours. Each battery had one bad cell. Since they are 4 years old, I am just going to replace them.
I am a little afraid to EQUALIZE them because in the LINK 2000 manual it says to turn off voltage sensative DC loads before equalizing a battery. I'm not sure what that means so I will just pass on equalizing.
What size (cranking amps) battery should I buy? Seems like I remember 990 or 1100 crancking amps is what is needed.
One more question:
Is parallel when there is a jumper from neg (#1 batt) to neg (#2 batt) and a jumper from pos (#1 batt) to pos (#2 batt)? I get those confused with series which I think is neg to pos to neg to pos (like a flash light).
Tuga, you are correct on parallel. Parallel gives you the same voltage, just more amperage. If you wire them in series, the voltage adds.
Richard Rhonda Ty and Alex Entrekin
1995 Newell # 390 DD Series 60, Allison World Trans
Subaru Outback toad
Often wrong, but seldom in doubt
Rhonda's chronicle https://wersquared.wordpress.com/
think of it like a flashlite. when you have an old flashlight with the C or D batteries in it, you put them front to back until you had filled up the chamber, remember? in doing postive to negative, you are adding together the voltages to get a brighter light. more batteries, the brighter light.
however, your starter in your coach is 12v. it needs 12v. however, since it is a HUGE starter, it needs a lot of CURRENT to turn over under the load of the engine. to do that, you need to have lots of cranking amps. amps are additive, so when you hook up in parallel, (positive to positive and negative to negative) you keep the voltage the same and sum the cranking amps up. even my f350 diesel truck has two batteries and when one of them is the least bit low, it wont start. diesels like to be spinning fast to start. remember, our diesels are basically a controlled explosion activiated by fuel and pressure. since they are high pressure in the cylinders, it takes lots of cranking amps to turn it over fast enough to get it started. for me, the fun example that is very illustrative are diesel powered pile drivers. the ones they use to pound bridge supports that are 3 feet in diameter down 100 feet. they set a huge cylinder on top of the support to be pounded in, support it on the outside gently, lift the piston (hammer) up and let it go as they squirt diesel fuel into the cylinder. it explodes, shoots the piston back up and it all starts over again. it is amazing to watch and they control the hammering pressure by how much fuel they squirt in. a simple one cylinder diesel engine that doubles as a hammer.
as to which 8D battery to buy, i have a simple approach....which is cheapest? that may not be the official newell approach, but it is mine.
there are not dozens of makers of 8D batteries and most are just remarked from a few manufacturers.
i bought mine at SAM's club and paid 135 bucks apiece. they are made by interstate and actually have higher cranking amps than the interstate workhorse batteries i replace. i think mine are 1400 CCa. SAM's club has their own interstate label.
can ya tell i took a long nap and now know i will be up all nite so i am writting to much?
as wally says, thats my two cents worth and i am sticking to it.
thanks. maybe all those years in engineering school helped a little.
i did leave out another comment. there are other posts talking about batteries. i do buy the cheapest for the starting batteries, but i bought AGM batteries for the coach side. i did get mine for 400 each which was as good of a price that i could find. i bought interstate AGM ones.
i do love tinkering on these things. a close friend got me a hat for christmas that says....."tinkering and traveling kind of guy"
i have never really participated in a web site like this one before in any substantial way, but i have spent alot of time here learning from the masters.
i have said before, i love my newell, but would have been very happy with a bluebird too....what i didnt figure was all the great i would make that along the way....
I feel like I gained a few IQ points reading Tom's explanation about series and parallel. Seriously, Tom, thank you very much for the verbal illustration. In a couple of years hanging around you guys I'll know enough about DC and AC to be dangerous....