I am working on my new radio, which man this 2DIN is AMAZING and the car thumps!!! But anyway I have an old amp I have hooked up to my subwoofer speakers. Radio wise all is good but I notice the car battery drains if I leave it attached to the battery post. (main power to the AMP)

I hooked up a multi meter from the + lead (disconnected from battery) to on one side and the other meter lead to the battery +. With nothing on, no draw at all, all 0's at 10, 20 and 200 setting. When I hook up the amp lead, I get a 0.01 draw on the 10 setting. Is this normal? thanks!

 

The amp should only be drawing power when the car is off. Actually it shouldn't be drawing power unless the radio is on. There should be a blue remote wire on the head unit that gets connected to the amp. This tells the amp to power on when you turn the radio on.

 

Thanks. I am aware of the blue wire on my new head unit. However a long time ago this amp had a brown wire connected to the power antenna pink wire on the car harness. This is to tell the amp the radio is on because power is going to the pink power antenna line. I left this alone and it works fine all over.

What concerns me is the main power line to the amp, a 10 gauge red wire is running from the trunk area to the battery (fused). If I leave this off car starts fine following day. If connected battery needs charge.

Hence I ask by connecting a multimeter from one lead to the battery + terminal and the other to the disconnected positive battery cable I have 0 draw. But once I introduce the 10 gauge wire from the amp to this test I get a draw of 0.01 (10 amp) setting. Just wondering ultimately if my amp is bad even though it works great radio wise?

 

Like said, amp isn't on unless your tuner is. If the tuner is off and no lights lit on the amp and it's still drawing power, yah amp probably shot.

 

ah ok. thanks that's what I wanted to find out. Sucks because it works great otherwise. Been a while since I had the subwoofers going.

I will invest in a new amp. thanks man!

 

It may be able to be repaired cheaply. Will it draw power if you disconnect the blue wire from tuner to amp ?

 

This existing AMP is an old HiFonics Pluto model. Originally it was setup with a small box (forgot what they are called) that converted from the rear factory speakers to the RCA left and right connectors, then to the AMP. I disabled all that and being the new head unit has the RCA connections I ran them straight to the AMP.

The only connections coming off the AMP currently are:
Orange to Brown, this tells the AMP connected to power antenna wire the radio is on

Red to battery

Black to ground

4 wires paired, 2 to the left 10" subwoofer and 2 to the right 10" subwoofer. None of these are blue unfortunately.

 

Gotta be the orang brown. Check that for 12v. when the radio is off. that could be your draw. With the source unit off there should be no voltage on that wire going to your amp. Does your amp have an on/off light ? Amps usually don't fail in this manner. With the head unit off there should only be 12 volts at the memory wire, usually yellow. red wire is switched 12v and should read 0 when the key is off.

Get the antenna wire off your amp. Head unit has a dedicated wire for the antenna, use it. Run the blue wire to your amp.

 

I did test the brown wire with a test light, nothing, will try with multimeter as well. The red does draw power with the car off. My thinking is their is some sort of short in the AMP. It does have an on/off light, and its off when the car is off.

one more thing, when I attached the red wire to the battery I get spark. That should not be happening I would think unless there is a short. There is an inline fuse on the wire but it has never blown.

 

Disconnect everything on the amp except the red and black. Test it then

 

ok good idea

 

ok so I disconnected the connector for the brown wire and speakers. and same result I get .01 read out now on 10m setting. So I guess I may have another short somewhere else? I get a strange clicking noise, not loud, from the right front engine bay when I connect positive battery lead either to the battery or through the multi meter.

What is interesting though is when I disconnected the brown wire/speaker wire connector from the AMP. I then attach the red lead to the battery, no spark.

The bottom line is when I leave the red lead attached to the battery the car needs a charge the follow morning. Whereas its fine for days if I leave it not attached.

 

brown wire / speaker wire. 1st paragraph said no change then 2nd para. yes then no draw. ???? Where is the clicking noise coming from ?

 

Ok whenever I attached the positive battery cable under any circumstance I get a click noise towards the front right engine bay. This has happened for a long time and does not really concern me.

Yesterday: I disconnected the pos bat cable, set the meter to test for any draw at 10amps. I then put one on the cable and one on the battery terminal, heard the noise by 0 draw. Everything was turned off, lights, etc.
When I put the pos cable from the AMP to this setup, I got a 0.01 draw.

Today: Same as above, now I get 0.01 draw no matter what I do

The thing that stands out is when the connector that has the brown wire and speaker wires plugged into the AMP, and then I attach the pos cable from the AMP (red 10 gauge), I get spark.

If I unplugged the brown/speaker wire connector from the AMP and again attach the red 10 Gauge power wire from the AMP, no spark.

 

So whatever the brown/speaker wire connector is attached to on the opposite end is switching the amp on. Never had an amp with a removable connector. Makes me think there is nothing wrong with the amp. And you say it works fine . I would investigate this connector

 

Could it be the capacitors in the amp loading up?