Electronic / stereo issues

[jeffro788]

Hey guys, I am unfortunately still on the old system as far as the alternator goes. I have put a small amp and retro radio in the truck and it works fine at low rpms but midrange rpms it cuts out. I have jiggled wires around to see if it is a loose wire but they are all secure and it doesn't phase them. I get the feeling that the alternator is not putting out enough power to send a strong enough ignition (remote) signal to the amp. I don't think there are any issues with the amp though. Everything stays lit up when it cuts out as far as the radio and light on amp, but no sound until lower rpms.
The amp by the way is just pushing 2 6x9's and 2 6.5's - no subs so it isn't pulling a lot of power.
I plan on going to newer alternator just hoping this is the problem.

[69halfton]

hm... where do you have the amp mounted?

I had my amp bolted to the floor of my truck, and with headers and whatnot being right underneight the floor is starts to get hot. I found that the amp was actually getting too hot and shutting itself off... spaced the amp up off the floor to get some air under it and problem solved..

high rpms can mean higher temperature... don't know where you have the amp mounted though..

[jeffro788]

Thats what I thought at first, but it will do it sometimes after being started from sitting all night so it is cold. It is under the seat and the amp doesn't really feel hot when I touch it. I think it isn't putting out the amount of volts for the remote wire. If I am not mistaking the old alternators only put out 12-13 volts, but I may be wrong. I have just never seen anything like it, unless the amp is bad.

[Dingfodgy]

I'd get out your trusty Fluke meter and see what the output @ the alternator is. Then I'd see what you are getting out of the voltage regulator. Test at various RPM's to see if either of those components are the culprit. Or you could just run a dedicated 12v power source directly off the (+) terminal of the battery and be done with it.

[mikajo39]

If you don't run directly from the battery, the alternator may not have the overhead to take the abuse from the amp. I have my amps grounded and a direct positive line from the battery and my keyed ignition coming off the cigarette lighter. Works pretty good

[big mike71]

Make sure you have the right gauge high quality wire.

[mikajo39]

Originally Posted by big mike71

Make sure you have the right gauge high quality wire.

Yeah make sure you run nothing smaller than 12 gauge for a low to mid power stereo. If you start getting into the big stuff you want 10 gauge or below.

[AceX]

It sounds to me like something is tripping the protection circuit. It could be either over-voltage, under-voltages or heat. Your multimeter should be your best tool as.previously stated. Could be time to swap that aging alt and/or the power/grounding wires.

[jeffro788]

I need to put a meter on the remote wire and go from there I guess. The radio is staying on as normal but there are no speakers hooked to radio, all are ran off the amp. If this is needed, I have all for speakers ran off a 2-channel amp, so it is at a 2 ohm load per channel, but it is suppose to be rated for that. I think the alternator is the problem, but I ha ve never seen anything like it, especially since the light is staying on showing the amp is on. About to go to a serpentine system with an upgraded alternator. Does anyone know what to do with the voltage regulator and how to connect the new plug on the modern alternators. I have been told it is very easy.

[mikajo39]

Originally Posted by jeffro788

I need to put a meter on the remote wire and go from there I guess. The radio is staying on as normal but there are no speakers hooked to radio, all are ran off the amp. If this is needed, I have all for speakers ran off a 2-channel amp, so it is at a 2 ohm load per channel, but it is suppose to be rated for that. I think the alternator is the problem, but I ha ve never seen anything like it, especially since the light is staying on showing the amp is on. About to go to a serpentine system with an upgraded alternator. Does anyone know what to do with the voltage regulator and how to connect the new plug on the modern alternators. I have been told it is very easy.

If it's a kinda cheapy amp it may be unstable or overheating at a 2ohm load, even though it's rated for it. Try running the speakers in a 4 ohm load and see if it fixes it, just wire your speakers in series instead of parallel.

[AceX]

If the amp is going into protect the power light should stay on but there is usually another light right next to it to indicate that the protection circuit has been tripped. It is possible that this LED is burnt out.

To add to this, it doesn't matter what an amp is rated for. If you push it too hard it will stop in its tracks. There may be other compounding factors causing it to trip. You might be clipping the inputs (which is impossible to detect unless you know what you're doing) and add a little heat and/or voltage problems and BAM! shutdown....

[jeffro788]

The amp is a MTX that I had ran subs off of before it is decent quality, I have an orion HCCA that I may put on there to see if it is any better, I know the HCCA can be bridged down to 1 ohm b/c I ran spl competetions with it, so I guess that could be used to rule out the overworking of the amp. I can try it this weekend. I still for some reason have the feeling that the alternator has something to do with it, I don't know why or what though. I haven't been stumped like this before on stereo stuff.

[mikajo39]

Well, to test it, pull the amp out hook it up to the battery and run it to your speakers to test it which bypasses the alternator, it'll show whether you have a bad amp or not. Or if you had a 12 V power supply you could bench test it.

[jeffro788]

I guess I could run a jumper from the positive to the remote input on the amp and do the same? Good call on that, I really need to test that first, it is the easiest to do.

[mikajo39]

Originally Posted by jeffro788

I guess I could run a jumper from the positive to the remote input on the amp and do the same? Good call on that, I really need to test that first, it is the easiest to do.

Just wire it all direct, postive on the amp to the + on the battery, Ground on the amp to - on the battery, and just hook up the remote to the + too. Direct test, cuts out the middle man and will tell you if it's your amp or alternator/electrical system.

[jeffro788]

will give that a shot.