okay im hooking up my amp and i have to connect it to a 12v item that is only on when the car is on. (remote). i have a pioneer head unit, and one of the wires coming from it is labled "system remote control unit" and leads to the little black box i will include a picture of. this same box happens to have one slot open for me to hook up the amp to. is this safe or will it cause some kind of short circut?

thanks all.

 

why do you want a relay for? if you have a pioneer head unit just connect the system control unit to the remote on the amp.......the system control unit wire on most aftermarket head units is a (blue/white wire) and in your amp you should have( + ) or battery...this goes direct to the battery .........( - ) or ground connect this to a good chassis ground the closer to the amp the better! and then your remote to the blue/white wire behind the radio.........if u still need info abot the relay or dont have a remote wire on the radio just hook the remote connection in the amp to ACC or IGNITION 84 and 85 in the relay is the coil .......30 and 87a are in a closed circuit when the coil is not energized and 30 and 87 are in closed circuit when energized( no connection between 30 and 87a

 

thank you! so you say splice into the blue/white remote wire OR acc? i found both... which would be perfereable?

 

remote B/c Its only on when radio or cd is on

 

If you want your power antenna to go up on your FC, you need to use the relay. Thats pretty much the only time you use a relay in your stereo install. The amp wire coming out of your headunit will turn your amplifier on with no problems.

 

the reason i want to put it into that relay is b/c i wont have to splice... i can just plug it in. if its the antenna relay, wont that only get power when the car is on? im a little hesitant to splice into the "remote" wire b/c i dont want to damage the headunit. the relay has an open slot so i was hoping that would work

 

on the FC they put a relay in there because the power antenna turn on is negative .....so what the relay is doing is basically switching the relay to provide a negative signal .when you turn the radio on ,since the remote or antenna lead output on the radio is positive........also make sure if you are hooking up an amp connect the remote to the (blue/white) behind the radio B/C some radios have both (power antenna and remote wire) power antenna is (blue)

 

well i spliced the amp remote into the blue/white wire labled "system remote control" and... nothing. the amp wont power up. its grounded to the car, its got 12V from the battery, i cant figure out what the problem is.

 

Read what turbo said. It's a negative switch relay. When that switch turns on it sends a negative out, so you can't use it to give a remote signal to your amp! Your headunit will have a remote out to use. Double check that the signal coming out of the headunit is a 12+ when on, not a negative. If it is a positive splice thre, not after the relay.

 

i spliced it before the relay. the pioneer unit should be sending a (+) out of the "remote" shouldnt it?

 

Did you test the blue/white wire coming out of the headunit to see if its sending out 12v? What model is your headunit?

 

not sure how to test it. its a Pioneer DEH-890MP. in the installation instructions... thats the wire they say to connect to the amp

 

???strange?.........recheck all your wires.......does the antenna go up and down when you turn the radio on and off?.............try this assuming everything is connected check your power coming from the battery to the amp .....check the remote power on and your ground.....this is very easy to do grab a voltmeter set it to VDC ........ground the negative test probe and touch the power 12V and remote with the other one .....it should read 12 on the battery and 9.5 to 12 on the remote one the remote .........then check your ground set the meter to continuity and put one probe to a good chassis ground and the other one to the negative connection on the amp..................if you are sure that all the wiring is good and the amp wont turn on Then you have a bad amp...=(

 

first check your amp as it's easy to do...just jump a small wire from the + to the rem on the amplifier...if it lights up, you're good there.

To test the remote wire on teh head unit, use a multimeter. Turn the radio on and then ground the black wire on your meter, and hit the other to the wire...it should show 12v. If you don't have a meter...it's a good investment to get one if you own an fc..lol.

 

Yeah if u own a FC ....He definetly needs a meter