[dougan]

I have an 88 CRX Si and the other night I was driving home on the highway and all the lights suddenly got really bright then back to normal. They continued to do this several times until I turned on the Rear Window defogger. They stayed at normal intensity until I turned off the RWD then they flashed brighter several times again.

At the point I left the RWD on and they were fine. Any ideas?

Thanks

 

[bobski]

Failing voltage regulator?

 

[Krix]

Is the battery light on the dash coming on?

the dimming and brightening could be the alternator putting out inconsistent voltage. Or you could have a bad connection somwhere.

As the voltage drops, your running straight off the battery, hence the dimmer lights. Voltage comes up, lights get brighter.

The only reason I could think of that would cause it to act normal when you put the defogger on is when you turn on loads like that the alternator bumps up voltage. So when you put enough load its putting out proper voltage.

A few things to check before replacing the alternator though are your grounds. Make sure your battery terminals are clean and not corroded up.
You have a plug and a wire with an eyelet that goes to the alternator. Check those for tightens and corrosion.