Rpm drop when turning on rear defroster and ac

[5speed00]

as the title says I've been having probs with rpm drop whenever I turn on the rear defroster or the ac(which I know happens) but I was wondering what I can do to fix this.

Was wondering if putting a higher output alternator would work ?

 

[R3dline]

nope, welcome to the world of honda

 

[RonJ]

Sounds like a failing alternator. Measure voltage across the two battery posts when there is no electrical load versus when there is high electrical load. Post the voltage readings.

 

[Ian123]

they should drop a little for a/c but i wouldnt think so for the defroster. Probably your alternator

 

[5speed00]

they should drop a little for a/c but i wouldnt think so for the defroster. Probably your alternator

Yea I figured it's the alt

Do u think it could be a bad ground?

And if it is the alt should I use oem or higher out put?

I'll test my alt and see I know it should be putting out about 14.0

 

[98 coupe]

upon heavy electrical load the alt will cause the engine to drop in rpm but only a couple hundred rpm not to much.
also normal alt output without load should be between 13.5 and 14.5 doesnt always have to be 14 on the dot, but the alt also puts out amps low amps without load, but upon load the voltage will drop to 12ish voltage and the amps will rise not sure off the top of my head what the exceptable range for a honda is but i would say between 60-100 amps.

how low do the rpms drop?

 

[RonJ]

upon heavy electrical load the alt will cause the engine to drop in rpm but only a couple hundred rpm not to much.

Under normal conditions, the truth is actually the opposite. When the ECU senses a high electrical load, it will compensate for the extra load by increasing the idle speed.

upon load the voltage will drop to 12ish voltage...

This is again incorrect. System voltage should NEVER drop below battery voltage, which is generally around 12.5V. If it does, the alternator is not working properly.