20 Most Recent JBL GTO75.4 Car Audio Amplifier Questions & Answers


Something is fried.

JBL GTO75.4 Car... | Answered on Sep 22, 2014


check the cord from deck to amp when you trun on the deck it should go from red to green some of amps you do need to run a blue wire from deck to amp. that the remot wire.. so you don,t need it going bysingle from the rca cable... I hope this help you out ty

JBL GTO75.4 Car... | Answered on Jul 08, 2013


Check your speakers with an ohm meter. They should have some resistance but not totally shorted. Its prob the amp that got fried. Connect the amp to the battery with no speakers attached to it if the protection light still comes on then the amp is blown.

If the amp is blown you can send it to people on ebay and get it fixed pretty cheap. Good luck!

JBL GTO75.4 Car... | Answered on Jul 06, 2012


It sounds like you have dirt stuck on the lazer head. Best way to clean it to get a good "wet head cleaner CD".You may have to run the cleaner several times to get all of the dirt off. P.S. make sure to buy a good cleaner disc, not the dollar store brand.

JBL GTO75.4 Car... | Answered on Mar 21, 2012


YEAH IF U CAN GET AHOLD OF JBL THEY CAN PROB.SEND YOU ANOTHER JUST LOOK UP THEIR NUMBER ON THE NET..COM

JBL GTO75.4 Car... | Answered on Feb 28, 2010


check your spker wire to see for a short.

JBL GTO75.4 Car... | Answered on Dec 07, 2009


replace head unit the cost to fix the problem you could but two deck ,use a wiring harness and get the aftermarket mountain kit

JBL GTO75.4 Car... | Answered on Jun 26, 2009


Hi

It's rare that 2 channels will fail simultaneously, are you sending 4 signals to the amp or just 2?

If you are sending just 2, perhaps the problem lies before the amp in the cabling to it, or the output from the headunit. If you are sending 4 signals then there may be a fuse in the amp that drives 2 channels out of the 4. Of course this may be the case should you just be sending 2 signals.

JBL GTO75.4 Car... | Answered on Mar 28, 2009


you may have to send it in or back to the company... being that its one side it could be a blown amp or perhaps a bad speaker on that side ..

hooking up two 6x9s and a sub in bridge mode you could have a wiring problem when i bridge an amp i go from positive of one side and negitive on the other to the same positive and negitive on the sub or box



+--------------------\
` bridge =========== > SUB
- --------------------/

hope this helps

JBL GTO75.4 Car... | Answered on Dec 26, 2008


i suggest using a 4 gauge or smaller i had the same problem. i switched from 8 to 4 and no problems!

JBL GTO75.4 Car... | Answered on Sep 29, 2008


It's likely that the amp has blown output transistors. To eliminate other possible problems, read through the following page:

Amp Going into Protection Mode

Let me know if you have any other questions.

JBL GTO75.4 Car... | Answered on Sep 17, 2008



With your multimeter set to DC volts, the black meter lead on the ground terminal of the amp (not on the point where the ground wire connected to the vehicle) and the head unit on (so the amp will have remote voltage applied), touch the red lead alternately to the B+ and remote terminals of the amp. If the voltage is below ~11 volts, you need to check the wiring feeding whichever line is too low.

JBL GTO75.4 Car... | Answered on Aug 20, 2008


If the amp is in protect mode, it probably has shorted output transistors. To eliminate other possible problems, do the following. I'll assume that you've checked the amplifier's on-board fuses.

With your multimeter set to DC volts, the black meter lead on the ground terminal of the amp (not on the point where the ground wire connected to the vehicle) and the head unit on (so the amp will have remote voltage applied), touch the red lead alternately to the B+ and remote terminals of the amp. If the voltage is below ~11 volts, you need to check the wiring feeding whichever line is too low.

If the voltage remains near or above 12v, disconnect all speaker wires from the speaker terminals of the amp and disconnect signal cables from the amp. If it powers up, the wiring needs to be checked. If it still shuts down, the amp almost certainly has shorted output transistors and will need to be repaired.

JBL GTO75.4 Car... | Answered on May 17, 2008


If the amp has identified a problem within itself, it could be 1 of a million things. Its best to go get it tested. It shouldnt be too hard if the amp has picked it up.

JBL GTO75.4 Car... | Answered on Feb 14, 2008


If the voltage is dropping to 8v, it sounds like there is a problem with either the B+ line or the ground connection. You should also check the voltage across the battery terminals to see if the voltage is dropping at the source.

The amp may be going into protect mode. Disconnect all speaker wires from the amplifier's terminals. Also disconnect the RCA cables from the amp. Does it still go into protect?

Insert a 20 amp fuse in the B+ line and try to power it up. If the fuse blows with no speakers connected to it, the amp probably has a blown channel.

JBL GTO75.4 Car... | Answered on Dec 05, 2007

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