After chasing many solutions including new starters, my Generac diesel genset is finally starting. The final solution was to power the starter sequence via the chassis batteries instead of the house batteries as it was designed. I put a jumper (battery cable) from the chassis batteries (2) directly to the cable that goes to the front of the coach and powers the solenoid and starter. My 4 6v house batteries apparently do not have enough combined amps to turn the gen flywheel anymore and they are only 2 years old.
I want to make this a permanent solution and need some advice about how to wire it.
I want to drill a hole in side wall and put the jumper cable from chassis battery to the strap behind JP2 (12v +) on the control board. That strap goes to the 30a breaker that the original cable attaches to as seen on the bottom right of the board (CB2).
Without a schematic can you tell if joining these will create a problem? The chassis battery and house batteries will be connected on the positive side. I don't know enough electrical to know if it will work or not (sparks fly).
It would give the amperage I need to crank the gen starter and turn the diesel motor. If this is a bad idea, then I will bypass the board and put in a 30a breaker directly connected to the original cable and not use the CB2 post.
Thanks for any ideas.
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John & Deanie, Corky and Benji (best buddies)
2001 National Marlin 390 DP
"Try to live up to your dog's opinion of you."
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I would fix the boost solenoid rather the tie the house and chassis batteries together.
Have you run your jumper directly to the house batteries. There may be a problem in the circuit board connections. 4, GC2 batteries will start that generator.
If you start and run the generator from the chassis battery only, you may find it going dead.
Most generators don't have charging systems and depend on the house charging system to supply its power to run.
If the charging is only going to the house battery the chassis battery will run down and die.
PS: Recheck CB 2. It has to be 130 or more amps. A 30 amp breaker will trip every time you try to start the generator.
Not a good idea to connect the chassis battery the way you describe. The generator requires in excess of 100 amps while cranking . Also , you will be using your chassis batteries to power the house loads . End result , all batteries dead.
Your house batteries should easily start the generator . I would start removing and cleaning all the big connections.
If you want to use the chassis battery to start the generator , connect the cable from the generator to the chassis battery.
I have not tried jumping from the house batteries. I will try that. The house and chassis batteries are both charged from either the alternator or the Xantrex converter /inverter. I have a battery tender on the chassis batteries to manage them while on shore power. Thanks for the suggestions. There have been a few times when the house batteries did start the genset but it was random and seldom.
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John & Deanie, Corky and Benji (best buddies)
2001 National Marlin 390 DP
"Try to live up to your dog's opinion of you."
There are several connections on the 40 foot path to the starter solenoid. I have thoroughly cleaned them all. I have also cleaned the ground connections to the chassis. Nothing worked until the jumper to the chassis batteries.
__________________
John & Deanie, Corky and Benji (best buddies)
2001 National Marlin 390 DP
"Try to live up to your dog's opinion of you."
Check You Tube for checking voltage loss. These processes will locate where you are losing power. Virtually all rv systems use coach batteries to start generator. There must be a bad connection or bad wire somewhere. Good luck.
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'02 Tiffin Phaeton 330 CAT
'02 Chevrolet Tracker Toad
I tried jumpering from the house batteries to the cable that I had jumpered from the chassis batteries. It started the engine...... I began to disassemble the control board to see if I could see what might be wrong with it. I found the JP2 bolt was loose. I tightened it really hard and the engine started without any jumpers. That circuit was minimal with just enough amps passing thru to try to turn the starter over but not enough to do it.
I tried restarting the genset a few more times from the original setup and it acted like it did not have enough amps to turn it over without struggling. Do the 6v batteries with lower amps than a 12v high cca battery, need a lot of time to recover after discharging its power to the starter? Normally I would just start the genset and run it as needed and probably not use it again for hours or days later. I would not normally keep restarting it like I am now to see if it continues to work.
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John & Deanie, Corky and Benji (best buddies)
2001 National Marlin 390 DP
"Try to live up to your dog's opinion of you."
Not all deep cycle batteries list CCA, but I found a AGM 190 AH that listed 670 CCA.
You have 2 series sets, so you have about 1300 CCAs.
CCA is at 0 degrees, so you should have plenty of CAs to start your generator.
If your loosing cranking power thru the circuit board, bypass it and add a fuse in the line to the house batteries. You'll need to research what size fuse the generator calls for.
Are your house batteries fully charged ? Maybe thats part of the problem.
Has anyone had issues with the cable that runs from the batteries in the rear to the genset in the front? I’m beginning to think the cable may be the problem. The genset will start sometimes. Usually after I have fideled with something. I don’t think it’s a connection issue as I have cleaned and tightened all that I know of. I think there are just not enough amps most of the time. The batteries are charged and I have used both house and chassis batteries and even connected them together.
__________________
John & Deanie, Corky and Benji (best buddies)
2001 National Marlin 390 DP
"Try to live up to your dog's opinion of you."
Has anyone had issues with the cable that runs from the batteries in the rear to the genset in the front? I’m beginning to think the cable may be the problem. The genset will start sometimes. Usually after I have fideled with something. I don’t think it’s a connection issue as I have cleaned and tightened all that I know of. I think there are just not enough amps most of the time. The batteries are charged and I have used both house and chassis batteries and even connected them together.
The main cables , from the chassis and coach batteries , from the tray to the front of the coach , should have a fuse ( or circuit breaker ) protection . Usually within 3 feet of the batteries .
My F/L diagram shows the circuit breaker for the chassis as 135 amps , in conversation with other members , the coach ( gen set starter ) cable circuit breaker may have a rating of 300amps.
On my chassis these circuit breakers are mounted on a plate on the frame rail behind the RR dual wheels, along with the starter relay , directly behind the battery tray.
Pictures are of the plate on my coach and a similar 12 volt circuit breaker that I found online . The only battery power in the coach not run through these circuit breakers is the cable to the engine starter.
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99DSDP 3884, Freightliner, XC, CAT 3126B, 300 HP /ALLISON 3060
2000 Caravan toad, Remco & Blue Ox.
The main cables , from the chassis and coach batteries , from the tray to the front of the coach , should have a fuse ( or circuit breaker ) protection . Usually within 3 feet of the batteries .
My F/L diagram shows the circuit breaker for the chassis as 135 amps , in conversation with other members , the coach ( gen set starter ) cable circuit breaker may have a rating of 300amps.
On my chassis these circuit breakers are mounted on a plate on the frame rail behind the RR dual wheels, along with the starter relay , directly behind the battery tray.
Pictures are of the plate on my coach and a similar 12 volt circuit breaker that I found online . The only battery power in the coach not run through these circuit breakers is the cable to the engine starter.
The main genset cable is connected to a 150 amp breaker on the rear circuit board. I have tried bypassing it and had same issues.
Does a multi-strand 3/8 in cable loose any conductivity internally over time? It is about 30' from the batteries to the genset, and except for the connection to the jack pump, it should be a continuous cable with no breaks. I think if the two were closer together it would probably start every time. But I have no way to test that without getting a stand alone battery and run it close to the genset. I don't have a spare battery to try that.
__________________
John & Deanie, Corky and Benji (best buddies)
2001 National Marlin 390 DP
"Try to live up to your dog's opinion of you."