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RV12 Volt system,not working I replaced 12 solenoid with the four connection

RV12 Volt system,not working I replaced 12 solenoid with the four connection


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Old 01-19-19, 07:40 AM
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RV12 Volt system,not working I replaced 12 solenoid with the four connection

I'm not sure what goes where , on the relay solenoid continuous duty 4 pole type the one I replaced was a 3 pole , I thought I was up grading to a more powerful unit,and it is a duel battery bank, I've fully charged my batteries, so how do I connect this 4 pole isolator solenoid,my start battery is good I've got the connection from the alternator and start battery to the solenoid isolator, and the other side battery positive cable connection to battery bank positive, running them parallel, but won't start house generator,
 
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Old 01-19-19, 08:35 AM
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What is the make and model of the solenoid?
 
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Old 01-19-19, 10:21 AM
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If I understand correctly I think you'll need to add a ground wire to the fourth lug of your new solenoid. Most 3 lug solenoids are grounded by the mounting bracket.

 
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Old 01-19-19, 11:13 AM
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Dane is correct so you'll need to add a wire to ground on the fourth terminal.
The two small terminals have no connection polarity.
 
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Old 01-19-19, 05:22 PM
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Thanks for the advice

I added the ground wire where I had placed the toggle disconnect switch,I guess I had them backwards, I heard that once you turn the ignition on position I would here it click,and so ive been hearing it, still no fire to my big in home generator, Ive had battery charger going off my 3500 generator but now my batteries voltage reads 5.7 no I tack that back on my Shumucker battery charger I just checked it states 100% and voltage 6 on maintain, I know I'm running them parallel but I got a filling the batteries are bad Right?? Still no off grid 12 Volt system running just my faithful 3500 Genny, I've check the converter, and breakers with light prob meter I've got power on 3 main breaker switches,and all the fuses check out, So it must be I need a new battery bank I bet, Fill free to let me know what you guys think, I'm new at motorhome living,have some other issues with water pressure as well ,thanks again
 
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Old 01-19-19, 07:30 PM
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I just checked it states 100% and voltage 6 on maintain,
Not sure what that means but you need a battery charger running at 12v to charge 12v batteries.

Your primary/starting battery and alternator get connected to one large terminal. The AUX battery bank gets connected to the other large terminal. This is a charging solenoid. It gets activated only when the vehicle is running or an emergency jump switch is pressed. Normally..... this relay stays open and the two battery systems run independently of each other.

You should have some type of built-in 12v power supply/charger to charge the AUX batteries and run the 12v accessories.
 
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Old 01-24-19, 07:24 AM
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You need to take a step back here...

Did the 12V system ever work? Why did you replace the solenoid?

In addition to the charge solenoid, there is also probably an isolator that will connect the 2 battery banks together when the alternator is producing voltage but isolates your chassis (truck) battery from the house when it's not running. My rig has both a 3-pole solenoid mounted by the alternator and a diode-type isolator mounted just above my radiator.

If your rig is configured like mine, the generator starter gets its power from the house battery bank. The solenoid allows you to draw from the house batteries to crank the engine in an emergency, but the isolator will prevent the opposite from happening (i.e., you can't power the house with the chassis battery). At least that's the way mine works.

You'll also have a converter that charges your house batteries when your RV is plugged into shore power (it will be plugged into a standard receptacle somewhere in the rig). Older converters (I'd guess mid-1990s and earlier) did not have "smart" charging algorithms and would routinely bake your house batteries if plugged in for long periods of time. These older converters also need a good battery in the loop in order to work properly. All of your 12V systems (furnace(s), fridge, lights, water pump, etc.) work off the batteries; the converter keeps the batteries charged when you have 110V power (whether from shore or the on-board generator).

Long story short, you need to make sure your 12V house system is functioning properly in order for the on-board generator to start. The chassis battery - and the solenoid - won't be part of the equation unless you're running the engine.

Make sure you actually have 12V batteries in parallel rather than 6V batteries in series. That's going to determine how you hook up your charger.
 
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Old 01-24-19, 08:05 AM
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Continuous duty solenoids are the preferred choice to combine and charge batteries. Those isolators use diodes and just over a half a volt is lost thru them due to the diode.
 
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Old 01-24-19, 09:33 AM
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I know - those diode isolators are sketchy. When they go bad, they can prevent the alternator from charging the chassis battery, too. This past season a friend replaced his battery and alternator only to find it was a bad isolator. But, they're very common on motorhomes. Just about all of the older rigs have them.
 
 

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