ICE problem, (suspected alternator)

[Struggler]

Right, after not having a sub in my car for about a month,
i finally get another jbl 1201.1 amp,

i install it, but dont get to blast it at all, (the mrs dont like it)
but today i was with my mate,
and we turned it up, and it cuts out,
keep it a very low volume, its fine.

the amp was last used in my mates car, i helped him take it out i know it was fine before it left him, it sat on top of his wardrobe for a month or two, but thats all,

ive had the exact same setup in that car before, and it worked fine, a hell of a lot louder than it is now,

i dont believe its the wiring, as the other amp (jbl 75.4) isnt setting a foot wrong, its wired with 0awg to a dist block, then 4awg to the amp,
with a 100a fuse, (but as ive said, this setup has worked for ages.

due to the sub playing at low volumes, i dont think theres a short in the speaker wire, and ive watched the amp flick onto protect mode (protect light just flashes, but sub cuts out for longer) so i dont think its the headunit or remote.

i did my investigating, and its worse (cuts out at a lower volume) with the engine off, and even worse with the engine off and lights on, aux belts are due a change, but theyre making no noises of slipping,

also it has an upgraded battery only a year ago so i dont think its that either.

could my alternator (oem) be on its last legs??
opinion on what my course of action should be,
going to do the aux belts this weekend and see if they make a difference.





if only i had a batman style WALLOP light to shine.

 

[wallop]

could my alternator (oem) be on its last legs??

If it was ^^this^^engine running or not wouldn't make a difference....

opinion on what my course of action should be

With regards^^this^^....

Check all fusing is tight, (running 0awg I assume your using ANL or AFS fusing)....

Check all power & earth cable connections....

Check 1201 earth site, (damp weather can cause slight corrosion which will raise resistance)....

Have you 'ADDED' a 0awg battery to chassis earth to match the 0awg power supply???

Check battery condition, (cold weather and long dark nights can play havoc with battery reserve capacities)....

The WALLOP batlight seems to be illuminating a power supply issue doesn't it....lol....My money would be on loose connection or poor amp earth causing a 'point of high resistance' inducing excessive voltage drop at higher draws....

 

[gaz_5103]

mine does the same.

 

[Struggler]

If it was ^^this^^engine running or not wouldn't make a difference....



With regards^^this^^....

Check all fusing is tight, (running 0awg I assume your using ANL or AFS fusing)....

Check all power & earth cable connections....

Check 1201 earth site, (damp weather can cause slight corrosion which will raise resistance)....

Have you 'ADDED' a 0awg battery to chassis earth to match the 0awg power supply???

Check battery condition, (cold weather and long dark nights can play havoc with battery reserve capacities)....

The WALLOP batlight seems to be illuminating a power supply issue doesn't it....lol....My money would be on loose connection or poor amp earth causing a 'point of high resistance' inducing excessive voltage drop at higher draws....

theyre anl fuses,
i accually think the fuse for the 1201 may be a tad loose,
ill check this in the morning,

the battery is earthed with a 0awg, and a 4awg, (just because the 4awg was the right length at the time) aprox 1" long each,

ill go over the wiring tomorro, loooooooooong,

would it be safe to assume, because the 2nd amp is working,
that the problem lies between the distribution block and the amp.

the amps are earth by 4awg wire running to an earthing block,
and then 0awg to the bolt for the black plastic thing behind the rear seats,
but i thought if it was the earthing site, would both amps not fall victim to the same thing??

other than the fuse, none of the wiring has put a foot wrong since is was all installed in november.

if this is the case,
is there any explaination for the problem worsening while the engines off

also, what am i looking for in lines of inspecting the battery??

taa

 

[Chris_786]

ask agithegreat he's in the know....

 

[polishdon@hotmail.com]

Mate its funny this topic comes up, i had the exact same thing, also with my JBL amp.... i went crazy trying to figure it out...actually Wallop was also reaching his end with my amp problem. The problem was exactly like yours, i turn the radio on, try increase the volume and the amp hits protect, i try increase gain, amp hits protect...if i decreased the gain i could increase the volume a little more than before, and then the amp would hit protect. So i ended up changing the earthing point (still the same), checked the power runing through the amp, 14.4 V (no problem there), checked for a voltage drop just before the amp hit protect, current was solid as a rock (no problem there), changed all my connections on the cables going into the amp and component sets....aaahaaaaaa

changing the endings wasnt the problem, however i did realise that when looking at the cable connections very closely, there were some areas where the connections were slightly slighty touching eachother, and in some instances only touching with a slight movement of the car. All in all the wires were shorting out, sending the amp into protect mode, insulated up those connections so no metal was touching metal....and presto, no more protect mode

instead i went on to blow my component set on the same day:dead: hahaha

cheers

 

[Struggler]

ill add that to my 'to do list' thankyou

 

[AlexG]

Gains set too high?

Bass boost on or too high?

 

[Skinny]

I bet your f**king clipping it to death. Actually, i'd stick a tenner on it.

 

[Struggler]

i not a complete r****d skinny J,
i dont believe the amps clipping at all, (cant say for certain as i dont have an oscolliscope)
gains on a smidge of minimum as my headunit has high voltage preouts,
and bass boost is completely off,

so £10 please

 

[kpowell911]

Check your earths, And check your fuses are in tight, I had this issue and my fuse wasnt bolted down all the way, in my distribution block, this was making the power connection loose. As regards alternator, I wouldn't have thought the system would be causing it much harm, Its not a rediculously powerful set up, I had a 3000wrms amp powering 4 12s, And 3 other amps powering componants and various screens in my old 1.2 8v, And Although i had 2 batteries, I didnt have an upraetd alternator, Just the big three wiring upgrade.

 

[Struggler]

im not going to lie,
i may have failed here,
i cant remember if a bolted the fuse down properly,
kept taking it out, put it in to test the amp,
took it out to install it properly,
put it in to test, worked (because i darent turn it up with my dad :S)

gna go check the fuse in a second

 

[Skinny]

Apologies then.

As crazy said, will be a lose connection, fuse could be likely. Also check the remote cable is allways getting a constant power form the HU with a MM.

 

[kpowell911]

For fear of upsetting you, It does also show the symtoms of gains too high, But if they are just past minimum doesnt sound like that.

 

[Struggler]

Apologies then.

As crazy said, will be a lose connection, fuse could be likely. Also check the remote cable is allways getting a constant power form the HU with a MM.

i understand your first post, living in essex you wouldnt believe the amount of times i see awfully set up systems in cars with 8awg power wires, and the gain (volume on the amp, as ive heard it called before) set near the top because its a 1000watzzzzzzzz max sub, and then get lectured about how i need a power cap,
just want to slap some people lol,


gain at 0 is about 7o'clock (yes i couldnt think of a better way of describing it so shh )
and i havnt used bass boost since i signed up to talkaudio lol

and gain atm is set to about 9o'clock, so it really is low, its the first thing i checked lol

im gna go look out my multi meter and poke it around now

 

[agithegreat]

I hope you have uprated engine wiring to run this amp. (alt to batt mainly)
Also i believe a bad earth could be to blame. Too much resistance. thus putting the amp into protect!
Check your voltage across the a,plifier terminals. Then get someone to turn it up slowly and watch the volts as it gets louder. If you drop it below 10.5ish it will go into protect! So check this. Let us know what you find!

Make sure you're on bare metal with the earth too. Sand the sh1t out of the bolt and the chassis to make it as sound as possible! Also check all other connectors onto the power wires to ensure that there aren't any loose!

 

[Skinny]

Out of interest, try a 150a fuse, having a proper read, i must admit i barley read 1st of all and just assumed, seems maybe on the small side. Also try playing some music and seeing what the voltage is like to the amp. After having tried a 150A fuse. Where have you earthed to? And with what?

Oh, stock wiring under the hood is fine for the moment with the power your running.

I ran a dls A6 and another amp with it fine.

 

[agithegreat]

I ran a dls A6 and another amp with it fine.

Into what load. If it was 1 ohm then sorry mate you ragged that A6, massive voltage drop, without uprated alt to batt cabling. It's less that 8guage... across 4' which essentially powers the device during engine on operation!

 

[Struggler]

well ive run a 1201 before,

its all stock under the bonnet, have some 0awg left so may put tb3 on my summer list lol,
except battery earth is 1x0awg + 1x4awg

amps running at 2ohm so the power drain shouldnt be too extensive,

ill sling a 150a fuse,

the fuses on the amp make 120a,
but its not working at full capacity

earthed with 4awg to dist block, then 0awg to the bolt that holds the rear seats down, sanded the paint down before bolting it down

 

[agithegreat]

Power output into 2 ohm is 1114 watt rms.
The units are not designed for loads under 2 ohm.
So you are drawing extensive power. Say it's 85% efficient, which is optimistic for this amp. 1310 w rms is being drawn. Which at a best case scenario is 91amps (14.4volts) but at worst case (12v)... it's 110amps. Along with your other amplifier(s). Is drawing some current!

 

[Struggler]

didnt really understand half of that, but ill try the bigger fuse and check the power suply,
thankyou

 

[PinkoCommie]

i did my investigating, and its worse (cuts out at a lower volume) with the engine off, and even worse with the engine off and lights on, aux belts are due a change, but theyre making no noises of slipping,

also it has an upgraded battery only a year ago so i dont think its that either.

could my alternator (oem) be on its last legs??
opinion on what my course of action should be,
going to do the aux belts this weekend and see if they make a difference.

While I don't pretend to know what I'm talking about, wouldn't the fact that it does it with the engine off suggest that it isn't the alternator at all?

Engine off = Alternator not spinning = Alternator not producing any power = all power drawn from the battery?

This is more to find out if my car electrical knowledge is worth the matchbox it's written on

 

[Struggler]

forgive me CS for i have sinned,

got me MM out,

climbed into the back of my car (its not as easy as it sounds with non reclining bucket seats)

turned to first click,
the amp went straight onto protect mode,
(as usual)

put the MM accross the terminals,
10v!

bum, just touch the fuse,
and it jumped to 12, and amp came on,
let go of the fuse, and protect,
screw the fuse down,
and amp stays on!!!

will leav it be as a trial tonight,
if it still misbehaves ill change the fuse and go over the wiring

cant believe i made such a noob error
im sorry for wasting everyones time,
but thankyou very much for all your help CS,
im ashamed to call myself an audio enthusiast :dapprove:

lol

 

[Struggler]

While I don't pretend to know what I'm talking about, wouldn't the fact that it does it with the engine off suggest that it isn't the alternator at all?

Engine off = Alternator not spinning = Alternator not producing any power = all power drawn from the battery?

This is more to find out if my car electrical knowledge is worth the matchbox it's written on

your knowledge rivals mine,
except i got it wrong

 

[wallop]

is there any explaination for the problem worsening while the engines off

Engine running, Alt charging at 14.4v & supplying current for car & audio....
Engine not running, Alt not charging, Battery supplying 'ALL' current for audio....

Winter months equate to colder ambient temperatures & longer nights, this results in prolonged use of the cars main electrics, (Wipers, Heater, Lights & Heated screens), which causes most batteries to run at reduced capacity, (lower capacity equates to lower float voltage)....

would it be safe to assume, because the 2nd amp is working,
that the problem lies between the distribution block and the amp.

With regards^^this^^....It would be safe to assume the 1201 isn't happy with its power supply voltage....SEE BELOW....

Car power supply is DC, so is heavily reliant on circuit resistance, higher resistance will sap voltage, lower voltage equates to less current being carried....

AS ABOVE....You could simply read your owners manual, (or download from JBL web site), and check what your amps indicating....These amplifiers have a basic self diagnosis system which will point you in the right direction, simply check out the 'TROUBLE SHOOTING' guide....


So its sorted.....

Wallops BATLIGHT shines again lol.....(That really made me snigger)....

 

[Struggler]

solved it mate,
it was the fuse,
but thanks anyway,
always nice to have people from TA around

 

[wallop]

Don't I get a prize????

Check all fusing is tight, (running 0awg I assume your using ANL or AFS fusing)....

Post 2,^^first recommendation^^.....

 

[Struggler]

ive got a medal if your paying postge

i knew id only need my searchlight

batmans useless in comparason

 

[wallop]

:lolup::lolup::cheers: