I have no sound from my 2001 Jeep GG Infinity Sound system. The HU lights up, shows channels, works the CD changer, accepts the CD,etc. only no sound. Is there a way to tell if the problem is in the HU or the amplifier. Also, do I have any options for aftermarket replacement. This is the third HU in this vehicle and I paid the dealer $400 for this reconditioned gem about 2 years ago. I may be interested in something other than the reconditioned original equipment and having someone other that the dealer do the work. Thanks in advance for any advice.
Replies (7)
kirchatndftbl on 04/10/2007 23:05:04
a wire could have came loose from the back of the HU did u check the wires at all?
swez on 04/11/2007 06:25:35
Check all fuses before doing any major surgery here. There may be more than one fuse in this system. One for the HU and another for the factory amps.
Also, do you know where the factory amp is located in this vehicle? If yes, you may have to probe it for voltage and make sure it is turning on.
At $400 a pop for a reconditioned HU from the dealer, you could get a very nice Aftermarket HU and either tap into the factory amp system with some help or just bypass the factory system altogether and go full aftermarket.
Swez
pensfan71 on 04/11/2007 15:00:35
Thanks for the help. I have not removed the HU and will do so to look around. I have the wiring diagram and it looks like the amp and HU are both powered by a single 25 amp fuse - I checked the fuse and it is OK. The amp is under the back seat and easy to get to. To check the amp do I probe (with a meter) the output going to the speakers, for example the (+, -) going to a door speaker? Also, it looks like there should be an enable signal from the HU to the amp to turn it on. I'm a little worried about frying something - can I probe the enable wire contact in the cable connector and use the ground contact in the connector or do I need a separate chassis ground to check that circuit? Thanks again.
swez on 04/11/2007 17:20:37
Yes, a meter is the right tool here. You will need to probe the wire harness going into this amp to see if there is DC voltage present on the input side of the amp.
Ground to main power lead = ~12.5 volts DC
Ground to REMote turn on = 12.0 volts DC when HU is switched on
If you find no/very low voltage readings at this juncture, it's back up to the HU and find out why.
If you have voltage on these tests and they are in range, then we look for audio signals in and out of the amp with AC voltage testing. The input side to this amp will be very low AC voltages. (1/2 - 2.0 volts would be usable. If that is not found to be working, again it's back to the HU for more diagnostics. (Probably a bench test needed at that level.)
If the HU proofs out as the culprit, might as well bite the bullet and replace this one with a reliable Aftermarket HU. You may need some harness adapters to use the OEM amp with an Aftermarket HU. One of our Pro installers can help you on that part. My background in OEM/Aftermarket integration is limited.
Swez
UKinstaller on 04/12/2007 09:52:17
just out of curiosity, do you have aftermarket speakers in the car?? could be a speaker grounding out.
-UK
ttocs on 04/12/2007 11:14:38
have we checked all the fuses, under the dash as well as under the hood? sounds like the amp is not turning on.
pensfan71 on 04/13/2007 19:30:37
First - Thanks for the troubleshooting help - Some answers to earlier posts - I have the factory speakers in the car. All of the fuses look OK.
I checked the HU output and I have 12.4 V main power to ground and when I turn on the HU I have about 12.3 V on the enable signal. I also have about 0.4 V ac from the HU going to the speaker inputs on the amp. Using the wiring diagram I probed the amp output contacts for each speaker and do not get any voltage. When I accidently touched the amp case while probing a speaker contact I get ~ .2 V ac.
Am I looking at a short in the amp? If so, it looks like I can buy one on ebay ($125) - probably re-conditioned. Can I also connect a new amp and are there adapters so that I would not have to cut any wires? Any opinions on the best approach.
Thanks for walking me through this.
Replies (7)
kirchatndftbl on 04/10/2007 23:05:04
a wire could have came loose from the back of the HU did u check the wires at all?
swez on 04/11/2007 06:25:35
Check all fuses before doing any major surgery here. There may be more than one fuse in this system. One for the HU and another for the factory amps.
Also, do you know where the factory amp is located in this vehicle? If yes, you may have to probe it for voltage and make sure it is turning on.
At $400 a pop for a reconditioned HU from the dealer, you could get a very nice Aftermarket HU and either tap into the factory amp system with some help or just bypass the factory system altogether and go full aftermarket.
Swez
pensfan71 on 04/11/2007 15:00:35
Thanks for the help. I have not removed the HU and will do so to look around. I have the wiring diagram and it looks like the amp and HU are both powered by a single 25 amp fuse - I checked the fuse and it is OK. The amp is under the back seat and easy to get to. To check the amp do I probe (with a meter) the output going to the speakers, for example the (+, -) going to a door speaker? Also, it looks like there should be an enable signal from the HU to the amp to turn it on. I'm a little worried about frying something - can I probe the enable wire contact in the cable connector and use the ground contact in the connector or do I need a separate chassis ground to check that circuit? Thanks again.
swez on 04/11/2007 17:20:37
Yes, a meter is the right tool here. You will need to probe the wire harness going into this amp to see if there is DC voltage present on the input side of the amp.
Ground to main power lead = ~12.5 volts DC
Ground to REMote turn on = 12.0 volts DC when HU is switched on
If you find no/very low voltage readings at this juncture, it's back up to the HU and find out why.
If you have voltage on these tests and they are in range, then we look for audio signals in and out of the amp with AC voltage testing. The input side to this amp will be very low AC voltages. (1/2 - 2.0 volts would be usable. If that is not found to be working, again it's back to the HU for more diagnostics. (Probably a bench test needed at that level.)
If the HU proofs out as the culprit, might as well bite the bullet and replace this one with a reliable Aftermarket HU. You may need some harness adapters to use the OEM amp with an Aftermarket HU. One of our Pro installers can help you on that part. My background in OEM/Aftermarket integration is limited.
Swez
UKinstaller on 04/12/2007 09:52:17
just out of curiosity, do you have aftermarket speakers in the car?? could be a speaker grounding out.
-UK
ttocs on 04/12/2007 11:14:38
have we checked all the fuses, under the dash as well as under the hood? sounds like the amp is not turning on.
pensfan71 on 04/13/2007 19:30:37
First - Thanks for the troubleshooting help - Some answers to earlier posts - I have the factory speakers in the car. All of the fuses look OK.
I checked the HU output and I have 12.4 V main power to ground and when I turn on the HU I have about 12.3 V on the enable signal. I also have about 0.4 V ac from the HU going to the speaker inputs on the amp. Using the wiring diagram I probed the amp output contacts for each speaker and do not get any voltage. When I accidently touched the amp case while probing a speaker contact I get ~ .2 V ac.
Am I looking at a short in the amp? If so, it looks like I can buy one on ebay ($125) - probably re-conditioned. Can I also connect a new amp and are there adapters so that I would not have to cut any wires? Any opinions on the best approach.
Thanks for walking me through this.
Copyright ClubKnowledge 2009 * All Rights Reserved
