CappyGolucky

Actually that wasn’t my pic. Sorry for the confusion but it looks like someone else jumped into the thread. Haven’t been able to post pics from my iPad but what I have is a very old and worn lookin solenoid relay which has been disconnected and bypassed. Youre correct however about the wire. Looks like about only 10 or even 12awg. I agree with u about upgrading it. This job is getting a little more complicated than I was hoping and I’m not big on messing around with electrical systems. May need to bring it in and get some help with it. Unfortunately there aren’t many RV techs in my area. May try a car audio shop. I know they work with dual batt systems some. Thanks for the help.

Yeah that was my intention to replace the old solenoid relay with the combiner. But from what you're saying it sounds like they are wired completely differently . I'll have to get under the hood and check it out but i'm pretty sure the existing isolator is being bypassed right now so the truck battery is directly connected to the coach batteries with no protection.

WME I took your advice and got one of those battery combiners off Amazon. Now I'm just trying to figure out the best way to set it up. Originally I had planned to locate it in the coach near the house batteries but instructions say to put it close to the engine battery. What's your take? Is it best to keep it placed where the old isolator was under the hood?

Yeah WME that post with the photo wasn't mine. Someone else jumping in I guess. I'm leaning towards going with the battery connector you recommended and maybe this spring or summer investing in a 100w solar kit for starters. Thanks for the help all.

Price sounds good to me. Not much more than a standard solenoid relay unit from what I’m seeing and definitely worth the peace of mind. So I have one more concern and that’s about the sound system. Believe it or not all the truck came with was an old CB radio so I’m having a new stereo installed in the cab. I was thinking it would be smart to have it connected to the coach battery bank for use during dry camping but now I’m wondering if that will be necessary. If I were to use the battery connector suggested would that hypothetically keep the truck battery charging from the coach battery bank (or the solar panels) if the stereo was drawing power from it while not running the engine?

So I think what's in there now is some type of a solenoid dual battery isolator. Looks to be a old as the truck and I'm seriously doubtful if it works. Probably why one of the previous owners decided to bypass it. So in your opinion what are the benefits of the battery combiner over the isolator? Is it because the charge can go both ways? Also, if I understand it this will effectively combine the two 6v coach batteries in parallel with the engine battery but in a way that negates the problem of them being different type/capacity? Is that right?

Yes I have heard conflicting views about this. Some say it applies more to wiring batteries in series than in parallel but still probably not the best idea. Here's one of the more persuasive descriptions I've seen https://www.homepower.com/articles/solar-electricity/design-installation/ask-experts-batteries-series-parallel So from the advice I'm getting here it sounds like maybe I should scrap the idea of mounting the old marine 12v under the hood and just go with the 2 6v wired in series in the coach. Then take WME's advice and get a new "smarter" isolator to connect between the coach and engine batts. I definitely had in mind as a future project mounting a couple solar panels up top (maybe 200w). Pretty sure that would keep us well supplied with power given the kind of low power devices/appliances we'll be running. Btw I've already got all the incandescent bulbs swapped out for LED's and have plumbed and mounted an Olympian Wave 3 catalytic propane heater which requires no electric for fans. So I'm definitely of the same mind when it comes to reducing draw.

No I didn't want to replace the truck battery. I just got a new one and it's in good shape. what I want to do is take the old coach battery from under the bench (inside) and install it under the hood. Then connect that to the isolator which right now I think is being bypassed. Then I want to connect that one in parallel with the 2 new 6V batteries which are now under the bench. So the idea is to have a coach battery bank consisting of the deep cycle 12 V battery under the hood and the 2 6V batteries inside the coach, and have all of those run through the isolator. I just had a new alternator put in which I believe is rated at 30 amps. Now are you saying that this battery setup will be too much for that for the alternator to handle? I intend to do a good amount of dry camping which is why I wanted a decent amount of battery capacity but will only be running a few lights, fans and maybe the radio. No microwaves or other high power appliances

I would post some photos but unfortunately I'm having trouble getting them to upload.

When I bought my 78 micro mini Sunrider last fall the coach battery, a group 27 deep cycle marine, was located under the dinette bench along with an old power converter the previous owner had installed The battery was wired and getting juice from the engine battery but wasn't going through the isolator which he showed me was mounted under the hood near the empty battery tray where I assume the coach battery was intended to live. After doing a bit of research I just picked up a set of 6 V golf cart batteries to upgrade my coach battery capacity. Here is what I'm looking to do and I could use some advice from anyone who's got more experience with this stuff than me, which is probably most of you. Lol. I've now got the 2 6V batteries wired in series under the dinette bench making one 12 V combo. I'd like to move the marine deep cycle to the tray under the hood and have everything go through the isolator the way it should be to protect the engine battery . Does this make sense? What's the best way to wire it up so that I am drawing power from both the new 12v combo and the marine deep cycle or is it a bad idea having the two batteries far away from each other. Also, I haven't come across anything that looks like a power center. Any ideas where it would be located or even if these early models had a power center would be helpful. Thanks.