relay/isolator connections

[norteno]

can I ground the relay/isolator on the same chassis bolt where I have the amplifier grounded??? and can I connect the relay/isolator 12v power lead to the remote turn on slot on my amp??? I have the amp remote turn on connected to my power antenna that only powers up when I turn on the head unit.

[alaskanzx5]

What do you want the relay/isolator for?

if trying to isolate a battery there is no need unless your going to be running the stereo with the car off all the time.

[norteno]

Yea, sometimes that and I have been reading different opinions about that. One is that it provides SOME power from the second battery to the amplifier and others say that it doesn't do anything when the car is running. There's a big long article on one car audio site from some dude named VIKING that sounds impressive about this subject so I wanna try it. I have a HO alternator, BIG 3 with 0 ga cables, soldered, not crimped connections, 0 ga POS running back to trunk, 0 ga chassis grounds, properly rated fuses, located close proximity to batteries. I have a brand new diehard up front and just happened to have a kinetic 1400 from before and everything else I need to install it so I'm gonna check it out and see for myself what happens, but I wanna make sure I hook it up correctly. My car is a 98 Cadillac Deville and I have been getting a low (12.2) voltage reading at idle @650 rpms, but goes up to 13.6 or more when driving around. Thanks for responding.

[MrSkippyJ]

absolutely serves no purpose unless you play with the engine off. And even then you are doing yourself a disservice by discharging the battery (or batteries) playing your stereo then starting the car and making the alt charge the batteries.

[SnowDrifter]

Ditch the relay.

For car audio it doesn't really serve a purpose. Exception would be a show car or something where you play it until the batteries die and still need to be able to start your car. But that's bad practice anyway since it will kill your alt trying to charge dead batteries.

Would be a similar idea if you had an RV or used your car to go camping. But for day-to-day bumping, you'll want the most direct connection to everything you can get and an isolator is simply a hindrance. I'd go so far to say that it would make things worse because it is A. a source of resistance, and another prat to fail. And B. makes it unnecessarily complicated to charge batteries. Instead of hooking your charger to the front battery and they will all be charged, you will need to charge the two separately. Doesn't really gain you anything

Edit: And if you are bent on keeping the isolator for some reason, you cannot wire it to the turn on of your amp. That is handled by your deck and cannot supply enough power on it's own to turn on a relay of that size. You will need to find either a different turn on source, or wire your turn on to a smaller automotive relay, then use that to activate your isolator

[MECHMAN]

absolutely serves no purpose unless you play with the engine off. And even then you are doing yourself a disservice by discharging the battery (or batteries) playing your stereo then starting the car and making the alt charge the batteries.

In other words Over working the alternator..

[norteno]

Thanks for responding. What are my realistic options for increasing voltage at 650 rpm? I've heard, read everything from installing smaller alt pulley, adjusting voltage regulator, relocating grounds, installing big 4, (I already have big 3), turning volume down at idle and turning it back up when driving, installing second battery with relay, relocating grounds, trashing alt and buying one from you or excessive voltage, or dc voltage or singer or whoever. What up???. Is there a definitive answer or is it just chasing the wind, LOL.

[MrSkippyJ]

typically if you want low RPM output you have to sacrifice some higher RPM output. You can use smaller pulleys to increase the overall alternator RPMs but you sacrifice alternator reliability and longevity that way.

edit-sorry almost a month late

[norteno]

That's OK. I'm just gonna install alt this week anyway. I just had the HO alt taken apart and shop said everything looked fine. It was originally rebuilt to 200 amps in 2011. I had recently been getting the "BATTERY NOT CHARGING" message but not all the time, just intermittently (sometimes it won't come on for days, sometimes it will come on and then go off while I am driving). I also been getting low voltage at idle, as I mentioned before, so I brought it back to him last week and this time he installed a 42mm pulley (the old OEM one was 62mm). Do you think that is too small?. I will also put in a 1/2 inch smaller belt and replace the tensioner. I did connect the isolator 12v lead to remote on amplifier and checked voltage both with car off and when running and I'm getting 12 v at the isolator. The isolator's owners manual says it needs 10v-16v to switch. seems to be working fine. I also been checking voltage often at front batt, at rear batt, at isolator and at amp and everything seems stable. The front and rear batteries are the same voltage when car is running and the rear battery is higher than the front when car is turned off. (rear is a kinetic 1400 and holds a higher charge), and it stays like this overnight and even when I don't drive the car for a while, the voltage is consistent and does not drop or drain so I assume and hope it is operating properly. I just grinded all connectors/lugs to shiny copper and re-sanded all connection points on frame/chassis, battery, alternator and checked insulation. Everything looks good to me, but then what do I know...LOL. Did I miss anything, any suggestions, Thanks for hearing me out and sorry for the long post.

[MrSkippyJ]

why exactly are you still using an isolator? You are not benefiting your system in any way by using one.