Battery Isolator for PD4106

[richard5933]

The deeper I get into this the more confused I seem to get...

Chassis batteries are a pair of 8D. House batteries are four T145 wired in series/parallel to give me 12v 520aH.

Bus has 8V71 with stock alternator.

Question is this... What size battery isolator do I need? I've read everything I can find on BCM, and now I'm even more confused. Much of it talks about 24v systems, but I've got a 12v bus. Some mentioned using solenoids instead, but I'm really interested in replacing the isolator already in place with a new one. Some mentioned getting a 300-amp isolator. Checked online and can't find one of those.

Before anyone asks what's in the bus now, the answer is I don't know. It's been there since 1990 and no labels are visible. It appears to be smaller than 300 amp for sure. Also appears to be a 3-wire set-up.

Anyone have suggestions as to the size isolator required? Any suggestions on particular brand/model which they've had success with? Recommended wire size to connect isolator to batteries/alternator? Most importantly, where is it best to get one of these things?

The only 300-amp model I've seen so far is EATON's Sure Power 3002, and it's about $450. Hopefully there are other options.

Many thanks in advance.
Richard

[Melbo]

I have one for sale.  Spare tire. 

Melbo

[richard5933]

Thanks Melbo. I just sent a PM about the isolator. Seems like the question of where to get one is answered.

Any thoughts about wire size?

Richard

[richard5933]

More about wire size...

If I understand this correctly, power flows from the bus alternator to the bus voltage regulator, and then from there it goes to the middle terminal on the battery isolator.

From what I can tell, the wiring running to the regulator all looks to be original bus wiring and in good condition. (Still with the OEM regulator)

The wire currently running from the regulator to the middle post of the isolator is painted over so I cannot tell for certain, but it looks to be a #6 or #8 stranded wire.

Question is this: What size should this wire running from regulator to isolator be? I'm guess that #6 or #8 are too small. Don't know what should be there though. Would love a bit of advice.

Thanks
Richard