HI98GS

I currently have a problem with my Nak system. I have the stock head unit and notice that the unit shuts down intermittently. I don't think this is the battery as the car starts up easily. The lights are not dim when I turn them on. I am not playing the radio loudly. I was wondering if anyone could shed some light on this problem. It seems that it shuts down when the radiator fan comes on. It shuts down for about 2 seconds then restarts. All the preset stations remain. The radio does not reset completely.

thanks for any suggestions

2jz_whoa

Most likely loss of power somewhere or you need a bigger battery. My system in my rx7 used to do that but i never really got it fixed just didn't turn it up real loud.

engin_ear

iTrader: (1)

I have the Nak system in my 99 GS (same system). When I was gutting all of the components except the headunit during my install, I experienced the exact same peculiar problem - the headunit would shut down a few seconds after I turned it on, and sometimes would run for a while and then decide to shut itself down. Nothing else in the car would be affected. But this was only with the engine off, if I remember correctly.
Reason: Battery was somewhat discharged. Charging the battery completely (overnight) fully eliminated the problem.
In your case, your battery may be going south, or you're not allowing it a chance to charge itself back to full charge. You can try a couple of things: 1) put a voltmeter across the battery to check its voltage the next time the headunit shuts down, or at any time; 2) fully charge the battery with an appropriate external charger; 3) replace the battery (Optima Yellow Top recommended - more money, but worth it).
The other thing, if this happens with the engine on, is that your alternator may not be working properly. Check the voltage across the battery with the engine running, should be 13-14 volts. If your alternator is dying, it will actually become a load on the battery (instead of charging it) and keep it in a state of partial discharge. Ugly.
The Nak headunit apparently cannot handle a low battery condition - either the voltage drops below its allowable threshold (likely), or the battery is not producing enough current to keep something active (less likely). I don't have an internal schematic for the headunit, but either its power-on circuit becomes disturbed and unhappy, or its voltage-monitoring circuit decides to shut down the unit by design because it can no longer support the operation of one or more internal components at the lower battery voltage, while everything else in the car is perfectly OK with it. I noticed after many, many trials that the Nak headunit is absolutely the first thing to go down as the battery voltage drops.