Amp not powering up

[VNexecutive]

okay so last night i was driving and my sub decided to cut out. i turned my headunit off and back on and it decided to work again
then it cut out again but this time it didnt work again. so this morning i checked all wire connections (including ground power and REM), and found out it had to do with the REM cord from the back of my headunit going to the amp.

this is the weird bit. the end of the cord leading to the REM is plugged in but it doesnt work, but while i was fiddling with it, part of the REM cord touched the power socket while part of the cord was still touching the REM socket. it worked.

what i really wanna know is why doesnt it work with the REM cord sitting just in the REM socket? why did it work when it was half in the REM socket and half in the power socket?

(also ill probably get flamed for doing a dodgy, but would it be bad to leave it like that? as in half in REM and half in power?)

only thing is when its like that it cuts out very quickly, not enough power getting through. im confused

PS sorry for the essay i just wrote, thought id give as much info as possible

PPS its a JBL grand touring sub by the way.

thanks in advance

[SweetWagon]

your "REM" is used to signal the amp to turn on, this happens when your headunit turns on thus feeding power to the REM on the amp. The amp draws its power from the large power wire, which goes directly to your battery (fused). Think of the REM (remote) as the turn on signal, when you bridged power from your main power wire the amp got the signal to turn on. DO NOT RUN THE AMP LIKE THIS. In your case it sounds like the REM has come loose behind your headunit. either patch it there using either a good solder joint or crimp connection if your not so good with a soldering iron, then use a multimeter to test if that gets power at the end of the wire (with the headunit on), else the wire is broken somewhere else and you will need to remove and inspect it.

cheers

[filthgrinder]

Yea best thing to do would be turn the HU on so its feeding power to the REM wire then go along with a power probe and see where the power is stopping, maybe theres a break somewhere along the wire and the whole thing will need replacing, or maybe its just a bad connection.

[VNexecutive]

vn6pwr - i checked the connection behind the headunit and it is all good. the wires are both wound together and electrical taped.

i will try that power check for leaks eventually. the wires are running under the door sills at the moment, so it may have been broken somehow there.

[filthgrinder]

Yea I've had to do it heaps of times, that little pointy screwdriver with the light in the top is my systems best friend

[r_i_d_a_h]

ground connections maybe? :S

[VNexecutive]

ground connections maybe? :S

nah mate as far as i know ground connections are fine. like i said i was driving and it was working but then it cut out. and i have no idea why. lol

[shaggerz]

vn6pwr - i checked the connection behind the headunit and it is all good. the wires are both wound together and electrical taped.

i will try that power check for leaks eventually. the wires are running under the door sills at the moment, so it may have been broken somehow there.

LOL I hate to tell you this but that is NOT "all good" as you say... that is a dodgy, crap connection. Re-do it with some solder & tape as an absolute minimum, preferably solder & heat shrink.

While you've got that join apart, check the remote wire from end to end with a multimeter. Measure its resistance because it might conduct, but poorly. Its resistance should not be more than one or two ohms from end to end.

Also, when you touched the remote wire to the power, theres a good chance you damaged your head unit thanks to the potential for reverse voltage into the head unit...

A series of very silly things has occured here...

NOTE: Also remember to NEVER EVER disconnect the amp's ground connection with the signal RCAs and positive lead still connected, because the amp will then be earthed through the sensitive, low level signal leads and through the head unit. The huge amount of current that amps can draw will BURN OUT the tracks inside the head unit (or in some cases blow an internal fuse) and you will kill the aux output of the head unit, sometimes involving smoke and a bad smell.

[VNexecutive]

LOL I hate to tell you this but that is NOT "all good" as you say... that is a dodgy, crap connection. Re-do it with some solder & tape as an absolute minimum, preferably solder & heat shrink.

While you've got that join apart, check the remote wire from end to end with a multimeter. Measure its resistance because it might conduct, but poorly. Its resistance should not be more than one or two ohms from end to end.

Also, when you touched the remote wire to the power, theres a good chance you damaged your head unit thanks to the potential for reverse voltage into the head unit...

A series of very silly things has occured here...

NOTE: Also remember to NEVER EVER disconnect the amp's ground connection with the signal RCAs and positive lead still connected, because the amp will then be earthed through the sensitive, low level signal leads and through the head unit. The huge amount of current that amps can draw will BURN OUT the tracks inside the head unit (or in some cases blow an internal fuse) and you will kill the aux output of the head unit, sometimes involving smoke and a bad smell.

okay ill re-do the remote wire at the back of the headunit.

the headunits fine.. so far lol.

thanks for the info though.

[VNexecutive]

soldered wires dont work. havent got the money to buy a multimeter and can't be f**ked to be honest. im sick of this sh1tty amp. i may have done stuff to not help it but why it stopped working in the first place is beyond me. can you tell im pissed off? ive had it for three days and it stops working on me. 3 days!!

last theory is to get someone elses amp hooked up to my system to my sub to see if it works cos i think the amp has died.

[SweetWagon]

my money is still on the rem wire, but if you want to rule out the amp being dead, make sure the earth is making good contact, then bridge a wire over from the main power lead terminal to the rem terminal.... it should power up else i would be checking your fuses.

edit: even though you soldered the connection, you need a test light or multimeter to check the start of the wire at the back of the h/u first, if it's working there then check the end of the wire, if both are working you know its not the problem. but try the above first^^

[VNexecutive]

...then bridge a wire over from the main power lead terminal to the rem terminal.... it should power up..

are you telling me to do what i have already done and was advised not to do? now im more confused! :P

EDIT: i think i understand what you mean. i had a better think about it lol.

EDIT2: so if i bridge the power across the way you say, and it works, its not the amp i guess? i really hope it is this way. cos i honestly cannot afford to just buy a new good amp.

[shaggerz]

are you telling me to do what i have already done and was advised not to do? now im more confused! :P

EDIT: i think i understand what you mean. i had a better think about it lol.

EDIT2: so if i bridge the power across the way you say, and it works, its not the amp i guess? i really hope it is this way. cos i honestly cannot afford to just buy a new good amp.

it is OK to connect the power to the rem terminal on the amp as long as the head unit is disconnected. If the amp powers up OK then it is fine and the problem is with either the remote wire from the head unit or the signal from the head unit itself. You should really go get a multimeter... cheap ones are like $10 and are very handy to have for this sort of thing. When the remote wire is not working, check for 12 volts between the remote wire and earth. My money is that it either wont be there or it'll be intermittent. Check if 12 volts appears on that same wire at the head unit end. If not, then the problem is with the head unit, but if there IS 12 volts at the head unit end and not at the amp end, the problem is a break in the remote wire somewhere and it will need to be replaced.

[VNexecutive]

heres a pic of what i think you guys are on about. is this what you meant?

[SweetWagon]

heres a pic of what i think you guys are on about. is this what you meant?

yeah but dont split it in 2 like that, disconnect the rem wire, then using another small peice just bridge it accross from the main power wire terminal. but dont permanentely run it like this if it works, the amp will be constantly on and most likely drain the battery or overheat. if doing this allows the amp to operate you now know its the rem wire causing the trouble. but as shaggerz said, it would be alot easier if you had a multimeter or a $5 test light. then could could check your main power, rem and earth, making it alot easier to diagnose your problem.

[VNexecutive]

okay i did it as the diagram shows and to no avail, also tried different earth spots. i have pulled apart my center console roughyl 500 times in the last week, does this mean im gunna have to do it again? :P

[SweetWagon]

not powering up or no sound? if that didnt work (different earth & bridging power wire to rem) then your main power wire may have blown the inline fuse, did you check the amp and power wire fuses?? but you really need a test light, it would make life easier when things like this happen.

[VNexecutive]

not powering up or no sound? if that didnt work (different earth & bridging power wire to rem) then your main power wire may have blown the inline fuse, did you check the amp and power wire fuses?? but you really need a test light, it would make life easier when things like this happen.

not powering up alltogether, i didnt bother putting the sub back in.
both fuses (power line and amp) are fine. im going to a mates who has a multi meter thingo. will report back in an hour or two. wish my amp luck (otherwise its copping the hammer )

[VNexecutive]

HAHA!















i suck at electronics. still cant get the fugger to work. tried the multimeter but not completely sure how to use one so i didnt get far with that (i thought i woulda still known from school but meh).. im just gunna try a mates amp in my system. if it doesnt work then we know its the remote cord.

[VNexecutive]

i found the problem.

*insert hilarious laughter*

the amp power cord wasn't connected to the battery properly.thats all
everythings fine.
i suck at finding solutions to things. LMAO

i feel like such a dumbass. everyone may laugh now. (please dont).

[Phreddy]

VNexec - like a couple of the other guys said, get yourself a cheap meter - $10-15 is great, and it will tell you a WEALTH of things. A test light is good too, although depending on the head unit, the remote output may not provide enough current for the lamp in these. LED types are fine, but those with a globe, well....

Anyhow, well done on getting it sorted.

[SweetWagon]

i found the problem.

*insert hilarious laughter*

the amp power cord wasn't connected to the battery properly.thats all
everythings fine.
i suck at finding solutions to things. LMAO

i feel like such a dumbass. everyone may laugh now. (please dont).

good that you sorted it out. a $5 test light could have solved that in about 2 secs