Amp pulls power even with key out

[82DMC12]

Hey all,

For the longest time, if I leave my D sitting for a week or so, my battery is too dead to turn the engine over. I finally looked at this and found my JL Audio sub amp pulls 0.05 amps even with the key out.

Question : is this normal?

If I disconnect the amp, other circuits pull about 0.015 amps combined.

How should I fix this? I could put some kind of disconnect on the amp. I went to O'riellys today and they have cut off switches but they were big 300 amp versions for an actual battery. Big, bulky, and overkill. I'd rather put a switch on the amp alone instead of the battery so my head unit doesn't lose its settings.

Anyone else dealt with this?

Andy

[Spittybug]

Dumb question, but what is the power source? If you merely wire it to one of the wires in our cars that is energized with the first key position, (green if IRC), then you don't need to worry about it. Sounds like it is wired to an "always hot", brown feed wire.

Did you install or did someone else? Where is it located? Trace the power lead back and see what it connects to.

[82DMC12]

The amp is wired directly to the battery. I have a power block and a ground block (2 amps, head unit, equalizer) , all of which connect straight to the battery. If I disconnect the power lead from the sub amp, the draw with key out drops to about 0.015 amp.

I did all the wiring myself and it was also went over by a pro installer. I don't know if the amp has always done this but I think it needs to be on a switch to reduce this draw.

Andy

[DMCMW Dave]

The amp is wired directly to the battery. I have a power block and a ground block (2 amps, head unit, equalizer) , all of which connect straight to the battery. If I disconnect the power lead from the sub amp, the draw with key out drops to about 0.015 amp.

I did all the wiring myself and it was also went over by a pro installer. I don't know if the amp has always done this but I think it needs to be on a switch to reduce this draw.

Andy

The reason the amp is wired to the battery is that it pulls a LOT of current when you're thumpin'. If you move it to be powered from the AUX relay you'll be disapointed. It best you should add a unique relay for the amp, powered directly from the battery but triggered by the aux relay.

[Bitsyncmaster]

Your stock door lock controller draws about 0.01 amps. Your stock clock draws about 0.05 amps. So that's the load your are seeing less the amp current draw.

[DMC5180]

The amp is wired directly to the battery. I have a power block and a ground block (2 amps, head unit, equalizer) , all of which connect straight to the battery. If I disconnect the power lead from the sub amp, the draw with key out drops to about 0.015 amp.

I did all the wiring myself and it was also went over by a pro installer. I don't know if the amp has always done this but I think it needs to be on a switch to reduce this draw.

Andy

Andy,

What is the the max current rating for the AMP? Once you know that number you can look for a secondary relay with sufficient margin to install as Dave S. suggested.

[82DMC12]

Dave, would you agree then that the extra 0.05A is excessive and causing my battery discharge?

I measured this by disconnecting the positive terminal on the battery and hooking up my multimeter inline to read the draw.

Andy

[Bitsyncmaster]

Dave, would you agree then that the extra 0.05A is excessive and causing my battery discharge?

I measured this by disconnecting the positive terminal on the battery and hooking up my multimeter inline to read the draw.

Andy

Well the amp is drawing 0.035 amp in standby. It probably is the normal load for your amp but it should have been designed to use less. It's not a problem with daily drivers which is how they get by with poor engineering. But a 0.050 amp load will defently be draining your battery. About 40 to 50 days would drain a new fully charged battery.

[DMCMW Dave]

It probably is the normal load for your amp but it should have been designed to use less. It's not a problem with daily drivers which is how they get by with poor engineering. .

Oh -you mean like designing a $2 relay into the amp itself?

[82DMC12]

Well I guess that brings me back to my original problem. My D has never been a quick starter, it always takes about 8 or 9 turns of the engine before it fires and I let go of the key. Sometimes after 8 or so turns I let go of the key, sit a second, then turn it again and it immediately starts.

But if the car sits for more than say one week to 10 days, there isn't enough juice to turn over more than once or twice very slowly.

I'm trying to fix the low power after so many days first, then I can see what to do about the long start.

Andy

[Nicholas R]

Seems odd. My amp only draws current when the signal wire from the radio is sending a signal to the amp.

[82DMC12]

Seems odd. My amp only draws current when the signal wire from the radio is sending a signal to the amp.

That's what I would have expected. But when I remove the + 12 wire from the amp the draw disappears.

Andy

[Elvis]

50mA is way too much for doing nothing.
Sounds like it's wired incorrect. It should only turn on when the radio sends the signal to do so.
Many amps also first need an additional sound signal to turn on.

Dave and me made suggestions how to reduce the standard ~15mA years ago.
The current I'm saving now is used for the alarm and remote pager and still draws less than your amp.

How old is your amp and what brand / type ?

[82DMC12]

This is a JL Audio 250/1, probably 7 years old or so. It has remote turn on so it is only lit up and running when the head unit is switched on. It's possible it is broken but it works fine otherwise.

http://img.tapatalk.com/a6fae3db-19fa-7fa9.jpg

[82DMC12]

Btw I have lockzilla for my door lock module if that makes a difference.

Andy

[DMC5180]

Well I guess that brings me back to my original problem. My D has never been a quick starter, it always takes about 8 or 9 turns of the engine before it fires and I let go of the key. Sometimes after 8 or so turns I let go of the key, sit a second, then turn it again and it immediately starts.

But if the car sits for more than say one week to 10 days, there isn't enough juice to turn over more than once or twice very slowly.

I'm trying to fix the low power after so many days first, then I can see what to do about the long start.

Andy

Not to to move off topic to much. But a slow start to me says no standby fuel pressure or a none functioning CSV. Do you have one of DAVE's (Priming) Solid State RPM Relays? When the engine does fire is it crisp on all cylinders or Progressive firing to all cylinders.

[David T]

You can do a few things to keep the battery from dying.
Add a battery master switch and turn it off when you are not using the car
Add a relay just for the amp as Dave S suggests.
Add a manual switch for the amp
Use a trickle charger (Battery Tender) when the car is not in use
Use the car more.
Load-test the battery. If it is over 5 years old replace it.

As for extended cranking when starting cold, check to see if the CSV is operating. You either have a bad Thermo-Time switch or there is a problem with the wiring. Try the plug swap. If it fires right up you know the CSV is not getting power when cranking cold.
David Teitelbaum






Not to to move off topic to much. But a slow start to me says no standby fuel pressure or a none functioning CSV. Do you have one of DAVE's (Priming) Solid State RPM Relays? When the engine does fire is it crisp on all cylinders or Progressive firing to all cylinders.

[DMC5180]

Btw I have lockzilla for my door lock module if that makes a difference.

Andy

I have the lockzilla w/remote too. I've never checked the draw of the unit in standby mode. It will kill the battery in about 4 weeks though. I make very good use of a DMCMW batt cut-off switch. One of these days I'll take the time to install the Digital Door lock unit sitting on my shelf. I have not done it yet because of the Remote integration. The wires for the remote unit are doubled into the lockzilla side of the connector terminals to make it plug-n-play. since I refuse to use scotch lock wire taps. I need to get another 9-way connector and fab up an intermediate harness.

[82DMC12]

Not to to move off topic to much. But a slow start to me says no standby fuel pressure or a none functioning CSV. Do you have one of DAVE's (Priming) Solid State RPM Relays? When the engine does fire is it crisp on all cylinders or Progressive firing to all cylinders.

Well I was trying to focus on the dead battery first, but here is some more info on the hard starting.

1. Actually is worst if the car is hot, then sits a couple of hours. That's when I usually crank it about 8 times, let off the key, then it starts right away second try. Embarrassing.

2. New accumulator lasy year. Verified rest pressure with a kjet tester. It is there and correct.

3. So far all I have done to try to fix it is I slightly richened my mixture. I have a dwell meter and until I did that everything was dialed in perfectly. The car perfectly and idles as it should. No vacuum leaks.

So I have two problems : parasitic draw and hard starting.

Andy

[82DMC12]

Oh, and I don't have Dave's relay. Just a replacement one from either DMCH or Grady a few years back.

[Bitsyncmaster]

The lockzilla draws the same current as the OEM lock unit. And accually the fanzilla draws 2 or 3 mills also.

[Bitsyncmaster]

Well I was trying to focus on the dead battery first, but here is some more info on the hard starting.

1. Actually is worst if the car is hot, then sits a couple of hours. That's when I usually crank it about 8 times, let off the key, then it starts right away second try. Embarrassing.

2. New accumulator lasy year. Verified rest pressure with a kjet tester. It is there and correct.

3. So far all I have done to try to fix it is I slightly richened my mixture. I have a dwell meter and until I did that everything was dialed in perfectly. The car perfectly and idles as it should. No vacuum leaks.

So I have two problems : parasitic draw and hard starting.

Andy

I had another user get my RPM relay for the same problem I found with my car. That was it would not start hot after sitting for 3 to 4 hours in the hot sun in the summer months. It turns out my car would hold rest pressure for 3 hours but the engine heat and heat of the pavement and sun would be enough to cause the symtoms of the bad accumulator hot start. My relay lets you set it to hold your rest pressure for an addional 3 hours and that fixed the problem on both cars.

[82DMC12]

Dave, PM sent!

[DMC5180]

Oh, and I don't have Dave's relay. Just a replacement one from either DMCH or Grady a few years back.

I forgot about the extra Pressure bump feature in Dave's relay. I've never needed to use it, but makes sense that it might fix your symptoms.

[82DMC12]

Just a quick update on this issue - I ended up bringing my battery in to NAPA to be positive the battery is OK - it tested bad so I bought a fresh one. I think it discharged too many times and became damaged.

I sent in my old RPM relay to Dave M so now I have the priming feature. I've only driven my car for a day with this relay but right away I've noticed a HUGE difference in how easy the engine starts no matter if it's cold, hot, or warm. Very happy with it so far!

As for the amp, I still haven't determined if the 5mA is out of spec or not, but I don't want to spend $300 on a new amp that might do the same thing. I have decided to install a normally-open relay like this one, second from the bottom:

http://www.wiringproducts.com/contents/en-us/d36_-automotive-relay.html

Dave M advised controlling it off the Aux relay, running off the small white/blue and the small black wire. With this installed the amp will be isolated from the battery unless the key is on so it can't draw down while the car sits in my garage. Some have said to just put in a battery switch - but then I lose all my settings on my Alpine HU, so it would be best in my case to just isolate the equipment that causes problems.

I'm hoping between the fresh battery, priming relay, and amp relay all of my problems will be solved!

Thanks for all the advice! And definitely get Dave's solid state relay!!

Andy