I know this is covered all over the place, but I'm still having some trouble with using a relay to apply 12v to my amp turn on lead inputs.

I hooked up the 30 amp relay just as it says -- remote lead to 86, ground (distribution block) to 85, +12 to 87, amplifier remote inputs to 30. The problem is that whenever I attach the head unit remote lead to the relay it overloads the remote lead and switches off all the amps (just the same as when I touch the lead directly to ground, or overload the lead by hooking up all 3 amps at once).

What am I doing wrong? How do I hook up a relay without overloading or grounding out the remote lead?

 

What kind of head unit is this?

You hooked up the relay right, there shouldnt be a problem...sounds like a problem with your head units output to me. Why would you ground out the remote turn on lead to begin with? Doing this mightve screwed something up in your head unit. Does the relay work fine when you hook up accessory (or any 12v) to 86? Because if so, I would say something in your head unit is screwed up. In which case I would just wire them to accessory at the steering column, therell be plenty of current for them there.

GL
kevin

 

It's a Rockford Fosgate 8320. The output specs on the remote lead is 400 mA max. Yes my system had an "accident" a while back involving a sub amp that wasn't screwed down. The damage hasn't been clear, since the unit works fine when hooked up to 2 amps (Alpine 4 ch in front and one of 2 SoundStream D200 II's in back).

What's the difference between hooking the remote lead directly to ground and hooking it to ground via the relay? I don't see the difference, it's still completing the circuit. When I attach a +12v lead to the relay it clicks, when I hook the remote lead to the relay it doesn't click, it just turns off the amps.

So I can hook up the amps' leads directly to accessory, without the relay? Where can I find the ignition harness on my 4th gen? I found the 97 Maxima wiring colors thing on a different forum.

 

Im still confused why you are hooking up your remote lead to ground. This could be your problem. This should NEVER be grounded.

But yes, if I were you, since Im lazy, I would hook em straight to accessory at the ignition harness without the relay. The ignition harness is the wires going to your key cylinder, so take off the panel covering under your driver side dash with a couple screws. Up under there should be five or six 12 gauge wires that go to your key cylinder. There are probably going to be two accessory wires going to your key cylinder, either will work fine. One will be red or red/yellow, and the other will be blue or white/blue. Probably should test this with a multimeter or test light to make sure theyre accessory (which means it will get 12 volts when you turn the key in any position except when the car is cranking). Hook em straight to either of those wires without any relay or anything, and youll be fine...

Or...if this is a little complicated for ya...
You can do everything at the back of your head unit, but I wouldnt put all 3 amps on the head unit's accessory wire. If you want to, you can put two of the amps on the remote turn on (since you say it works with only 2 of the amps on it) and put your mids/highs amp on the radio's accessory, which is the red wire going into the back of the radio. This wire has the same function as the ignition harness accessory wire, but is small gauge, so putting all 3 amps on it might be a little unsafe, but one wont be a problem at all.

Hope thats easy to understand lol I kinda rambled so it might take a few tries to get everything
-kevin

 

Im guessing your just "stepping up" the output of your HUs remote out? If thats the case then the correct way would be..

Constant 12V to 87
Ground to 86
HU remote to 85
Output to amps is 30

And Kevin you should know this....

 

wow, am i braindead much or what, i have no idea what i was thinking

well it was 4 am but still...

 

LoL its all good.

 

I figured it out! I'm guessing that my HU's remote lead was damaged or something during my "accident" and can't power the relay (no click even when the relay was the only thing on the lead). I bridged the relay, putting power to my amps' turn on leads, and they all work fine. So I'm going to put the relay on accessory or something when I get motivated. In the meantime I hooked up a switch to the +12v to turn the amps on and off.

I'm so happy I figured this out, I thought a couple of my amps that were involved in the "accident" were blown... nope just my HU remote lead. Phew! My system rocks once again! I shall once again enjoy my long Seattle commute.....

___
Rockford Fosgate 8320 HU
Alpine MRH-355 bridged powering component Focals up front
Rockford Fosgate Punch 55.2 powering Focal mids for rear fill
Coustic 401SE powering 2 JBL GTO 12" DVC subs
Sweet, rich, and wholesome :-)

 

well hang on....now im confused reading post #1 for the 3rd time

what he had different from what you wrote is he reversed HU remote and ground, he put 85 as ground and 86 as remote instead of vise versa. Wouldnt this work just the same?

*edit-my post was to don, you can disregard it if you figured it out, but id still like to know if don reads this
maybe i wasnt so dilusional at 4 am

 

Polarity shouldn't matter, should it? I hooked it up according to the instructions on the back of the package (which agreed with every other help page I found online).

 

If the input mwas on 86, then hed be sending 12V where it needs ground whenever he turns on the radio. To add to that hes throwing a ground where he needs 12V when turning the radio on. Using 12V on both the 86 and 87 would typically be used to change the - input on the 'trigger' going into 85 to a +, but not bumping up the power at all. Although thats all in theory. Similiar to when you need to change a wire from - to + you would throw 12V Constant to 86 and 87, - input to 85, ending with a + coming from 30.

WoW I hope this came out right. I hate remembering the numbers, its always easier to look at the relay....

 

Post #5 is 110% correct, I do it ALL the time, including my own car...

 

Had to read it a bunch of times to get it...and I get your argument about he had 12v where he needed ground, and sent ground where he needed 12v...but this is just simply reverse of what you do and will work either way iirc. 85 can either be power or ground, and 86 can be power or ground, as long as theyre both not the same thing. He was triggering the relay by sending 12v to 86, and 85 was ground.


im gonna feel like an @ss if im wrong now cuz i think this is the first thing ive debated with god..oops i mean Don

 

Theoretically you would be right. But remember a relay acts as a switch and needs a 'trigger' to open/close the latch. Therefore needing 85 as a trigger, rather than a constant. 87 and 86 would always stay constant providing + and/or - whichever the use is.

 

I agree...so his diagram coulda been correct 'theoretically' if he used the HU remote to trigger 86...

But anyway...got any thoughts on the interchangeability of 30 and 87? My asst manager was arguing with me that I should use 30 as the input and 87 as the output, but I see no difference either way.