Curious about the amp relay I read about in the NSX manual

[Larry Bastanza]

Something very strange is afoot under my hood Relay box A is not populated in the way that you and the service manual detail. Where the power amplifier relay is supposed to be located, not only is the that spot in the relay box empty, there are no contacts present to receive one. Does anyone know if there was an alternate location for the relay in a '02 model or an alternate relay box layout? The car has never been wrecked so no rewiring would have been done by an ignorant body shop electrician.

Additionally, I checked all of the relays in that relay box per the procedure outlined in the service manual and all are good. I'm so confused

OK, I have a copy of the 97-05 ETM manual which is specifically for electrical troubleshooting. According to that book up to 01 the relay is in the back. However for the 02 car the relay is in the front, so the amp relay is the one in front on the passenger side with the three in a row in your pic.

HTH,
LarryB

 

[Old Guy]

OK, I have a copy of the 97-05 ETM manual which is specifically for electrical troubleshooting. According to that book up to 01 the relay is in the back. However for the 02 car the relay is in the front, so the amp relay is the one in front on the passenger side with the three in a row in your pic.

HTH,
LarryB

I have the 1997 full manual and 2000 supplement for my 2000. Neither manual provides a relay layout that matches the layout in my relay box A. Where do you acquire this magical ETM manual?

 

[jwmelvin]

P/n 61SW001EL
PL 1000.2002.04.02
$40 on eBay

 

[clean_green]

Thanks Larry! You da' man

 

[Larry Bastanza]

View attachment 123136
P/n 61SW001EL
PL 1000.2002.04.02
$40 on eBay

I do stand corrected, it is actually the 97-02 ETM manual......... The real benefit of this book is as opposed to drawings found in the service manual, this manual has a full picture of every component, very helpful, and clarified the relay question immediately.

 

[clean_green]

Thanks Larry and Old Guy for all the help and info on the relay :smile: Unfortunately, that wasn't the problem so the search continues. I just bought one of the ETM manuals and will use it to continue my search for the elusive, audio stealing gremlin in my system. I will update this thread as needed.

 

[clean_green]

I am not sure that the problem is with the head unit. If you measured the voltage between the Y / R wire and the black wire (ground) at your sub woofer you should be getting +12v with the head unit switched on. The head unit has to be on because it controls the power amp relay. If the head unit is on and you are getting 0.5 v on the Y / R wire, it almost seems like the contact in the relay has failed or you have a very poor connection somewhere in the circuit.

As a thought, you may be able to find the location of the relay by having somebody listen to the relays in Box A while another person switches the head unit on and off. If its quiet enough they may be able to hear the click of the amp relay. That said, relays tend to be pretty dumb-ass simple devices and are not failure prone (notwithstanding the problems with solder joint failures in the main FI relay!).

One other thing to check. Does your power antenna go up and down? The power antenna gets its 'on' signal from the same pink / white wire that goes to the amp relay. If the antenna is going up and down then the control signal from the head unit is working and the amp relay should also be switching unless there is a broken wire some place. If your power antenna has stopped operating, then you could have a problem in the head unit itself or the pink/white control wire coming out of the head unit could be broken some where.

I am happy to say that I fixed the problem yesterday and I now have tunes again :smile: I must admit, I don't fully understand why it came back though.

After Larry accurately located the power amplifier relay for me, I tested it per the procedure in the service manual and determined that it was good. I was also getting 12V to the power amplifier 20A fuse in the forward fuse box. Nothing more to see there so I moved on. I then checked the voltage at the antenna connector in the trunk, as Old Guy suggested, and the constant 12V lead was powered (as expected) but the switched 12V lead was not. I had tapped the switched lead to power my Shark Attack II antenna and the transmitter for my wifi rear view camera so I began to suspect that one of those had gone bad and was causing a short, thus preventing the amps from energizing. I cut the power lead to the antenna and viola - the radio came back to life with a burst of static! When I reconnected the antenna, there was radio silence again. Next I removed the wifi transmitter power and again the radio came to life. This was getting weird! The antenna and wifi transmitter had peacefully coexisted for at least 6 months prior and now they weren't playing nicely? I reconnected the power to the antenna and looked for another place to get switched power for my transmitter. I located a four pin connector about a foot or 2 forward in the trunk that i believe was a left over from the OEM phone so I rang it out to find ground and switched power and connected the transmitter there. Now, everything is all good again :biggrin:

If anyone can explain why my original wiring scheme worked for so long and then suddenly stopped, I would like to know for future reference. Anyway, thanks to all who helped me find a solution. Prime is the greatest!