Hey I have a 91 rx-7 na and for a while now the dash lights, headlights, taillights and pretty much anything that is lit, pulses and flickers. I tested the battery and replaced it and then checked the alternator and it put out about 73 amps if I remember correctly. After about 5 minutes of driving it does this. Also when electrical loads and added (headlights+braking) brings the rpm down and even keeps it down at times. Even my radar detector which is connected to my cig lighter for 12V gives an alert of "high voltage" Could this be the voltage regulator? I am thinking so. I have checked vac leaks and all that stuff so any help would be appreciated! I will probably try a buddies out and see if it makes a difference

 

welcome to the board.

seems like it could be the voltage regulator. you mentioned checking the alternator current, but have you checked voltage just to confirm?

 

my car does this as well when at very low idle speeds. yours sounds like voltage regulator. my idle is set to low to charge properly I think.

 

I didn't check the voltage but the only verification I do have is the voltage that the gauge displays. I have tried to raise the idle slightly but at this point my adjuster doesn't make a difference. I feel like this voltage regulator has to do with the idle quality and even when I am cruising at night at say 2800 rpms it will pulse hard the same way. I will try a different alternator and see if it makes a difference! Thanks!

 

yes. that should do it.

 

Also is it safe to say that when the alternator is acting up (overcharging+undercharging) it can make sensors and idle quality poor? I would think so but just want a second opinion

 

Yes it can conceivably happen as you suspect. Ignition coils get power from the Main Relay, so they see whatever voltage the alternator puts out. Lower voltage generally means a weaker spark, but your battery should have enough reserve capacity to keep it in the happy zone for long enough. I'd still toss that alternator in the trash and give it a Taurus Alt tho. 130 amps from a common junkyard part and only needing minor bracket fabrication and a MazdaTrix pulley is hard to argue with

 

Thank you for the insight my friend!!!