My car is a 99 Accord Sedan, stock F23 motor with 138,xxx miles. Whenever the car gets up to temperature and I am in traffic, when the fan cuts on, the car starts to shake very violently and it is very loud. This occurs regardless of whether or not the A/C is on. Are my fans bad? A thought that has been kicked around at 6ga.com is that my battery is insufficient or my altnerator is bad... as in, the extra load of the fan is putting a strain on the altnernator, and I know I need my belts changed. This plausable?

Would doing the "Big 3" grounding mod potentially help?

Thanks in advance.

 

Sounds like your idle speed is too low and the alternator is having a hard time keeping up because of it. The low idle speed could be related to a failing IAC valve as well.
A grounding kit will not fix this. Just be sure the grounds you already have are clean and tight.

 

Do a google search for Votage Drop Testing, as mentioned and as you are thinking, the fan ground must be good and your alt recharge wire must be in good condition.

You may also have an ELD issue, it senses electrical loads and ups the idle accordingly. Does the idle go up when you turn the AC on, if it does then I would trust the IAC.

 

The idle doesn't change when the A/C is on or off, but I never noticed it ever changing? It doesn't really run rough per se. I did notice it sounds funny with the A/C on... I'm really starting to suspect its the serpentine belt. I'm pinching my pennies to get those belts changed.

 

TTT

Any more ideas from anybody?