Lately, I've had issues with my accord when it rains out. If I'm on the brakes too long at a stop, the tach drops to 0, the lights in the dash and the headlights dim if they're on and my subwoofer cuts off. As soon as I accelerate again, everything "charges back up" and is working fine again. I've ruled out the sub/amp being the issue because I disconnected everything and the problem still exists. What could be causing this?

 

Sounds like you need to clean the outer iacv mesh filter.

 

I think you misunderstood, the actual idle of the car isn't changing, just the tach gauge turns off and drops to 0

 

Is the charging light coming on ? It could be a bad alternator. You can try testing the alternator with a multimeter. When the car is fully warmed up and the headlights on, it should be putting out atleast 14 volts at idle.

Still clean out the iacv filter.

 

only light that comes on is the ABS light. Alternator is fairly new but I'm not ruling it out, will probably test it soon. Thanks for the advice.

 

I'm with "holmes" - something in the charging system is not to spec. Check and clean all ends of both battery cables, be sure they are clean and tight. Have the alt tested just to be sure. Also inspect the "power" cable from the alt back to the battery/fuse box

There are some "cheap" voltage gauges you can buy and install in the car - one just plugs right into the cig/power outlet and read the voltage of the car as it is running.

Just so you know, low voltage will trip the ABS light

 

thanks for the tip just bought one.

Car Vehicle Voltmeter Voltage Gauge Volt Meter Cigarette Plug Monitor 12V 24V LN | eBay