UNDERDRIVE pulley probs = 9v HELP !!!!!!
UNDERDRIVE pulley probs = 9v HELP !!!!!! RECENTLY i swaped my subs out installed a 3 farad cap and swapped a crank pulley..
as of now my car runs at 12.4 volts with no accessory drag (according to power cap voltage meter) when the system is up,the voltage can drop as low a high 9V's at which point my hi\mid's amp starts cutting out (not ran to a power cap) (uses common ground with bass amp and 3 farad cap) My guess is the alternater has been slowed to **** by the crank pulley swap and im having big electrical system deficencies? Im tring to pull 1500w rms out of a RF 1500.1 (which it just benchmarked) can anyone verify this im using 4 ga wire all arround...
also the system runs fine for the first few minutes after i start the car (and a overnight trickle charge on the yellow top) voltage is then mabye 12.8v (with car on) but after 2 or 3 songs the hi\mid amp starts cutting out when the system is really hitting..
before th pulley and cap install the amps ran fine but i did not really push the rf amp to its max....
any comments appriciated but keep in mind i have been doing stereo installs for a few years and us to do it for professionally so the "check your ground" type answers have already been troubleshooted...
thanks,
john
as of now my car runs at 12.4 volts with no accessory drag (according to power cap voltage meter) when the system is up,the voltage can drop as low a high 9V's at which point my hi\mid's amp starts cutting out (not ran to a power cap) (uses common ground with bass amp and 3 farad cap) My guess is the alternater has been slowed to **** by the crank pulley swap and im having big electrical system deficencies? Im tring to pull 1500w rms out of a RF 1500.1 (which it just benchmarked) can anyone verify this im using 4 ga wire all arround...
also the system runs fine for the first few minutes after i start the car (and a overnight trickle charge on the yellow top) voltage is then mabye 12.8v (with car on) but after 2 or 3 songs the hi\mid amp starts cutting out when the system is really hitting..
before th pulley and cap install the amps ran fine but i did not really push the rf amp to its max....
any comments appriciated but keep in mind i have been doing stereo installs for a few years and us to do it for professionally so the "check your ground" type answers have already been troubleshooted...
thanks,
john
if you have been doing systems professionally for a few years, then why would you use a common ground for a cap, sub amp and hi/mid amp ?
also, have you started to trouble shoot your car's electrical system (try testing it with no amps/ subs etc) then go from there. I dont think that it is in your install, but rather you may have a bad alt, or the wrong pulley
also, have you started to trouble shoot your car's electrical system (try testing it with no amps/ subs etc) then go from there. I dont think that it is in your install, but rather you may have a bad alt, or the wrong pulley
[QUOTE=jimmy 2 Times]if you have been doing systems professionally for a few years, then why would you use a common ground for a cap, sub amp and hi/mid amp ?[QUOTE=jimmy 2 Times]
not to argue but your suppose to use the same grounding location if possible to prevent ground loops....
i dont really think my alternator is bad.... im just guessing its running really slow due to the crank pulley swap
not to argue but your suppose to use the same grounding location if possible to prevent ground loops....
i dont really think my alternator is bad.... im just guessing its running really slow due to the crank pulley swap
If the voltage goes up when you run the engine @ 2500 rpm's and then discharges @ idle then the problem is the underdrive pulley, if the voltage is at 12.8 when you start like you say then you have problems from the get go. should be 13.0 or better. Does it get over 13 w/o the stereo? I've had some of my systems pull more power than the stock alternator can produce and use a high output version. Shouldn't be down to 9v though.
Sure you don't need this:
http://www.thunderracing.com/catalog...vid=3&pcid=111
I intend on replacing my stock underdrive next year, and have been told some cars need the additional pulley, and some don't. I have been told that high output systems require it, but cannot confirm this until next year's install.
http://www.thunderracing.com/catalog...vid=3&pcid=111
I intend on replacing my stock underdrive next year, and have been told some cars need the additional pulley, and some don't. I have been told that high output systems require it, but cannot confirm this until next year's install.
Last edited by Firehawk526; Oct 5, 2005 at 08:33 PM.
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for street, ditch the underdrive pully. the losses to the electrical and cooling are not worth the small gains in HP. sounds like alt isn't being turned fast enough. put a smaller pulley on it. like the link above offers.
[QUOTE=Jpr5690][QUOTE=jimmy 2 Times]if you have been doing systems professionally for a few years, then why would you use a common ground for a cap, sub amp and hi/mid amp ?
not to argue but your suppose to use the same grounding location if possible to prevent ground loops....
i dont really think my alternator is bad.... im just guessing its running really slow due to the crank pulley swap 1st an amp of that size should have at least 2 guage wire unless it is only 4ft or less from the battery
2nd have you tested the voltage at your battery and then at you amp with the system playing? If so what is the difference?
3rd if the bass does not cut out try wiring the mid/highs amp to the cap too that should help.
Another thing that may help is to put a heavy guage ground on the battery if it has not already been done.
It is really too bad you have no real stereo shops in daytona to help you.
Originally Posted by jimmy 2 Times
not to argue but your suppose to use the same grounding location if possible to prevent ground loops....
i dont really think my alternator is bad.... im just guessing its running really slow due to the crank pulley swap
2nd have you tested the voltage at your battery and then at you amp with the system playing? If so what is the difference?
3rd if the bass does not cut out try wiring the mid/highs amp to the cap too that should help.
Another thing that may help is to put a heavy guage ground on the battery if it has not already been done.
It is really too bad you have no real stereo shops in daytona to help you.
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[QUOTE=Jpr5690][QUOTE=jimmy 2 Times]if you have been doing systems professionally for a few years, then why would you use a common ground for a cap, sub amp and hi/mid amp ?
not to argue but your suppose to use the same grounding location if possible to prevent ground loops....
i dont really think my alternator is bad.... im just guessing its running really slow due to the crank pulley swap That just means you want 1 path to ground for each component in system. It doesn't mean they have to have the same route to ground. Ground loops are a problem because they can act like an antenna and cause noise in sensitive systems. The 12V system in the average car is so noisy as to make no difference.
Originally Posted by jimmy 2 Times
not to argue but your suppose to use the same grounding location if possible to prevent ground loops....
i dont really think my alternator is bad.... im just guessing its running really slow due to the crank pulley swap
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Verdad Gallardo ok the voltage jumps up to 14.6 when i rev it to 1500rpms...after yet another full trickle charge it played fine for like 15 min with the car on but eventually the highs started cutting out . when this happened i went and took a look at the voltage meter and it was a constant 9.9 (this was while the bass was hitting prolonged low frequency and the high speed engine fan was on)... my conclusion is im just taxing the voltage system too much, and hopefully this overdrive pulley will resolve the issue the highs amp is on its own 8ga run from the battery and is grounded in the same location as everything else so to me this seems like the only logical conclusion????
That just means you want 1 path to ground for each component in system. It doesn't mean they have to have the same route to ground. Ground loops are a problem because they can act like an antenna and cause noise in sensitive systems. The 12V system in the average car is so noisy as to make no difference.
only 1 path taken they are all on seperate cables just grounded in the same location ..i.e. 1 bolt 3 wires off of it
only 1 path taken they are all on seperate cables just grounded in the same location ..i.e. 1 bolt 3 wires off of it
the only other thing im not 100% comfortable with is the the cap wanted me to use a distrubition block for the ground and power wires (4ga in x1 and 4 ga out x2) in the past ive had a seperate ground for the cap and ran the cap in line on the amp's power wire... but i figured id follow the instructions.. to me this is really not allowing for as good of a ground than if i ran a seperate ground wire for the cap alone and amp alone but lie i said i followed their directions and used their install kit ect...
Originally Posted by Jpr5690
the only other thing im not 100% comfortable with is the the cap wanted me to use a distrubition block for the ground and power wires (4ga in x1 and 4 ga out x2) in the past ive had a seperate ground for the cap and ran the cap in line on the amp's power wire... but i figured id follow the instructions.. to me this is really not allowing for as good of a ground than if i ran a seperate ground wire for the cap alone and amp alone but lie i said i followed their directions and used their install kit ect...
Why don't you wire the highs amp to the cap too. It must be helping if the sub amp isn't cutting off. Keep in mind if you didn't ground the battery with a 4ga wire or bigger you will have a huge voltage drop. It would be like flowing water through an 8' pipe with a 1 foot opening on the other end.
Try this for T.S. Let your system get to the point where the Voltage drop is the heaviest.
Turn it down. Bring the RPM's up to about 1500-2000. Try 1500 for now. Bring the Volumn up and see what it is doing. IF it works fine, then your Car doesn't like the Underdrive pulley much at all.
Also, a capacitor can act like a resistor when it is trying to re-charge. if the disharge time exceeds the Re-charge time, the Capacitor becomes a resistor as it brings it's Re down and increases system resistance. It will want to fill 1st.
This is why most SPL systems do not use Capacitors. They use another product like BatCap's or other similar item.
ALso check you wiring to see if it is getting hot. That would indicate whether or not 1 4ga line is enough. 1500 RMS watts and up, require alot of juice. I used 1/0 for 2500 Watts. You are close to 60%-70% of what I ran. 4 ga sounds a little small.
A check for this is to get a reading off the ALt post and them measure again at the battery, and the cap, and then the Amps. See what is happening with your power. Seems like it's a combo of Alt. Underdrive pulley, and a Charging/power system that may be taxed.
Turn it down. Bring the RPM's up to about 1500-2000. Try 1500 for now. Bring the Volumn up and see what it is doing. IF it works fine, then your Car doesn't like the Underdrive pulley much at all.
Also, a capacitor can act like a resistor when it is trying to re-charge. if the disharge time exceeds the Re-charge time, the Capacitor becomes a resistor as it brings it's Re down and increases system resistance. It will want to fill 1st.
This is why most SPL systems do not use Capacitors. They use another product like BatCap's or other similar item.
ALso check you wiring to see if it is getting hot. That would indicate whether or not 1 4ga line is enough. 1500 RMS watts and up, require alot of juice. I used 1/0 for 2500 Watts. You are close to 60%-70% of what I ran. 4 ga sounds a little small.
A check for this is to get a reading off the ALt post and them measure again at the battery, and the cap, and then the Amps. See what is happening with your power. Seems like it's a combo of Alt. Underdrive pulley, and a Charging/power system that may be taxed.
ok, earlier when i had the system all the way up, the highs were cutting out i reved it and it helped alot with the cutting out (cutouts became much less frequent) but still it happened a little bit what i need is to get someone else to rev it while i check the voltage meter with the system up also what really compells me th say this is just a taxed voltage system is: everything was fine (even at full volume) until the high speed fans turned on while the system is up. hell from what i saw they droped my system voltage by a whole volt ... hopefully tommrow my pulley will be here if i can get the system to be at 14.6 then it might only drop into the 11's while its hitting which to me would much more acceptable than starting out in the 12's and dropping to 9's
glen, for the hell of it im going to double up on my batt ground and see what happens as of not its the stock wire but im pretty sure thats a 4 ga wire (havent really looked closly though)
glen, for the hell of it im going to double up on my batt ground and see what happens as of not its the stock wire but im pretty sure thats a 4 ga wire (havent really looked closly though)
one last weird fact is the amp is on a 100 amp circuit breaker for te last 3 years now , its never tripped once but from what ive read the amp should pull up to 180 amps???
--why is always my system that has problems? ive built over 100+ systems for others with minimal problems but every time i work on my one ****, something gotta go wrong!--
--why is always my system that has problems? ive built over 100+ systems for others with minimal problems but every time i work on my one ****, something gotta go wrong!--
just to update i added a 8ga wire(all i had) to the battery ground and im not sure if it did anything but what i can tell you is with the car off (ie. no fans) the lowest it goes is 10.8v so at this point it seems that im just pulling too much at once with the fans, and having a slowed alternator....
YEP! seccond i turn the fans on (with the car off) highs amp cuts out (10.1v) ..... hopefully i can run fans\some ac\ amps when i get he new overdrive pulley .....
****! the brakes are gonna kill me....!!!!! mabye ill have to get a bigger alternator?
****! the brakes are gonna kill me....!!!!! mabye ill have to get a bigger alternator?
Ok, it seems to me that you are over taxing your electrical system, because you are running the pulley. Since the alternator spins slower now it is going to be over taxed much easier. Also I would think that with that power, any power cord over 4ft or so should be 0/1gauge. I would think you would run one 0/1 gauge from the battery to the cap, then a 0/1 gauge from cap to the input of a distrobution block, then one 4gauge out from distro block to amp and one 4 gauge from the distro to the other amp.