So I bought my S2000 a few weeks ago (yes I still need to introduce myself in the forum) but I'm having an odd issue with my the aftermarket JVC deck that was in the car when I bought it.

At odd times (can't pinpoint circumstances) it will just cut out and look like it lost power completely, sometimes it'll come back on and other times it"ll be off for the rest of the drive. Now I figured it was a loose connection but the odd part is that I can press the 'clock' button on the deck and the clock will show up, I can even press eject and it will eject the CD, but the deck itself will not turn on. Then randomly when it does turn back on it goes through its whole startup sequence which means that it did in fact cut out.

If it was the power wire wouldn't the clock and eject functions also not work? Or are they somehow powered off a different cable?

I will check the connections on the weekend just haven't had time but wanted to get some insight from some of you pros.

 

There are two power connections - one switched with the ignition, and the other on constantly
for memory. If the switched connection failed, either through bad wiring or a bad fuse, the
clock and eject functions would likely still work, if that's how JVC designed it (one might
want to check the time or eject a CD after shutting off the car). The dual connections are
the reason that there are actually two fuses for the headunit, #9 & #22.

 

Thanks a lot oth! I'll look into it tonight actually and see if its simply a loose wire.

 

So I tried fixing the wires, nothing was loose. This is really strange, could the honda harness itself be damaged? Nothing looked corroded or anything and i tested each wire out. the only thing that would make a difference was if yellow was connected the clock and eject would work. I even tried a different deck, same issue. I'm lost :s

 

So I checked the wiring and everything is fine. Now what happens is when you turn the car on the deck goes on and off like 5 or 6 times in the span of 2 minutes then comes on fully and works for the rest of the drive. It does this every time but always ends up working now. I checked the ground and its properly connected but I'm thinking the factory ground is corroded perhaps? Should I try using a different grounding point? If so, where?

Thanks.

 

I doubt the ground is bad, as it also supplies power to the clock and eject functions, which you say work when the HU quits.

Suggestion - Plug some low-power accessory into the accessory power socket that will be easy to monitor to see if it has power, such as a cell phone charger that has an LED on it. The accessory power socket is on the same switched circuit as the radio power, so the next time the radio goes out check your cell phone charger to see if it has power. If it does, then the problem is closer to the radio, either a bad connection on a connector, fuse holder, or (doubtful) the ground wire.

If both the HU and cell phone charger go in and out together then I would look at the accessory power socket relay, I have heard of some cases where they go bad. It's up under the dash to the right of the steering column along with another relay, both of which disconnect power to various circuits when the engine is cranked. The reason power is disconnected is for 2 reasons: 1 - to prevent voltage spikes created by the starter motor from possibly damaging the electronics in the HU or whatever accessory you have plugged into the socket, and 2 - to make sure power-hungry equipment like the AC and fans are turned off, allowing full power for starting the engine.

The positions of the relays vary by model year but the one you want has a yel/red wire and a wht/red wire; the other relay has yel and blk/red wires and controls the power mirrors, DRLs, HVAC and rear defogger. The relays are the same and they can be swapped for troubleshooting. If you're desperate you can temporarily connect the yel/red to the wht/red, bypassing the relay. This means the power to the HU will NOT be interrupted when you crank the engine, possibly creating some voltage spikes that could damage it. So if you do the temporary bypass make sure the HU is turned off when starting the car.

 

Thanks modifry I will try this out and report back!

 

So the accessory power socket does seem to be working (although the led slightly flickers). Any suggestions at this point? Should I bother with trying another grounding point for the HU or is that pointless? Should the relay still be looked at?

 

Here's an update: It appears to be a voltage issue of some sort. If I plug in an accessory the HU will not work, as soon as the accessory the HU turns on again. If I play radio on it its fine and doesn't cut out, but when I plug in a USB or run bluetooth, it will intermittently cut out (more power draw I guess). Could this be linked to a faulty relay?

Mind you everything else in the car works 100% as it should, no flickering of lights, gauges, or anything like that.