battery isolator/relay

[Honkity Hank]

I am not sure these are one in the same so I need a little help. THere is a relay that is supposed to connect the house batteriers with the coach battery when the starter is energized. I say supposed to but in our case this is not happening. The relay is located, on our coach, behind the pull out battery locker, mounted on the coach frame.

It does not have a part number on it but has (if I remember correctly) 3 poles. Does anyone know the replacement part number?

This does not look like it but I found it at PPL, Will it work?

Thanks

[lewster]

Hank,

Isolators come in a lot if different amp ratings. You need to know the output of your alternator and match one to that. Here is a list of the NOCO brand that you are seeking:

Delcotron:
90 amp.......IGD-90-CS
120 amp......IGD-120-B
200 amp......IGD-200-B

Standard :
90 amp........IGD-90HP
140 amp.......IGD-140HP
200 amp.......IGD-200HP
270 amp.......IGD-270HP

Prices range from $50 up to $127.

If you have 3 posts on the isolator, it might be a SurePower brand. They range from 70-160 amps and cost between $40-95

[ALANSD]

and once you pick the right size, the brand name is just a personal choice. I have a 200 rated on mine with a 135 amp alt.

[shelocta]

I have an '83 310 MH and the strater boost relay is tied to the start swith. But I think on most models there is a switch or button in the glove box so you can use it when the engine bater is low. Of the 3 wires on your relay, if 12 volts is applied to the terminal with the small wire you should here the relay snap closed.
Good Luck
Bill & Kat

[guy99]

Hank,
Be careful! The relay which connects your house battery to your chassis battery is usually controlled by a switch as Bill said.

This functionality is NOT the same as your battery isolator which keeps your house and chassis batteries separate EXCEPT when the engine (alternator) is running. This is done so that you do not discharge your chassis batteries while camping without external power. The last thing you want is to have dead batteries and no way to start your engine.

[Chuckles]

There is an alternative....

I have fitted the Sterling Battery-to-Battery Charger.

It acts as an isolator, Diode and boosts charge to the coach batteries.
Check out www.sterling-power.com

Chuck

[arodriguez60]

What yuo are looking for is a continuos duty silenoid. Works like a ford silenoid. It connects the house battery(s) to the starter battery while starting the vehicle. You should be able to buy one at Napa or carqwest autoparts store. Ford also used them instead of an isolater on their camper specials. Do not use that isolater that you show in the picture. It uses diodes as a one way doorway for electricity and cannot handle the amperage that the starter will use and will burnup instantly.

[Howard Lefkowitz]

Originally Posted by Honkity Hank

I am not sure these are one in the same so I need a little help. THere is a relay that is supposed to connect the house batteriers with the coach battery when the starter is energized. I say supposed to but in our case this is not happening. The relay is located, on our coach, behind the pull out battery locker, mounted on the coach frame.

It does not have a part number on it but has (if I remember correctly) 3 poles. Does anyone know the replacement part number?

This does not look like it but I found it at PPL, Will it work?

Thanks

From your Post it is not clear what you want to do.
1. There is an emergency start circuit that uses a momentary contact switch in the glove box to hook all of the batteries together. This allows easy starting with a weak coach battery. Their is a relay near the batteries which does the connection.
2. The battery isolator allows both the house and coach start battery to be charged when the engine is running. That is the picture you have shown. This only works when the engine is running.
3. When you are connected to 110AC you are only charging the House batteries and not the starter battery.

So which is not working or what do you want to do?

[Honkity Hank]

Originally Posted by Howard Lefkowitz

From your Post it is not clear what you want to do.
1. There is an emergency start circuit that uses a momentary contact switch in the glove box to hook all of the batteries together. This allows easy starting with a weak coach battery. Their is a relay near the batteries which does the connection.
2. The battery isolator allows both the house and coach start battery to be charged when the engine is running. That is the picture you have shown. This only works when the engine is running.
3. When you are connected to 110AC you are only charging the House batteries and not the starter battery.

So which is not working or what do you want to do?

I replaced the relay near the batteries, I think that was not working properly. I am not sure where the momentary contact switch is that you say is in the glove box. Is that a manual switch or automatic?

Thank for the insight on the isolator, I think it is working properly.

Jeff

[Howard Lefkowitz]

It is a manual switch and is usually located on the top of the glove box (It hangs down into the box). When you pull it on it energizes the relay and connects the coach batteries to the engine battery. This gives you extra starting power. It is strictly for emergency starting which is why it is spring loaded to turn off when you release it.

[Lyall]

The photo looks like a rectifier isolator rather than a relay. Lyall

[Lyall]

I have a relay on my 1995 Ford. The one I first put in was from RadioShack and burned out after a dozen years. I bought some Bosch 12 volt relays from B. G. Micro and the sockets for them. I wired them in and they work fine. You need a 12 volt relary with about 30 amp contacts. Lyall