Flickering Lights

[BremertonMSP]

I've noticed since I've had my MSP that at night the headlights will flicker regularly.

Does this car have such a piss poor alternator that when the radiator fan comes on it draws so much initial current that it causes the lights to dim a bit? And I swear if it happens while I'm accellerating, it causes the engine to stumble slightly

Anyone else notice this:confused:

[Familia323]

I put Silvania Silverstar bulbs in my car, and I've noticed that they flicker occasionally too. I wasn't too worried about it though.

[1sty]

turn off the radio :D

[SOSPEED]

Yes the same thing happens to my car as well. What would happen if it was a cold rainny and foggy night. You got your head lights, fog lights, wipers, heater fan, radio, and gauges, if you got them, on. I think the car would just die..... lol

[MP5Raycer]

my head lights and also interior lights do as well i hate that shit

[1sty]

I can almost turn off my lights with the radio if I really want to :D

[macklum]

when I first got my O1 LX ,I noticed this as well .Turned out I had a faulty altenator ,I had it replaced under warrenty .

[BremertonMSP]

So it seems that the alternators in our cars are a bit marginal. I remember reading that they are 80amp units, wonder if there are any 130amp units out there that would fit in our cars.

Guess I have some homework to do, or hey psifactor, you work at a mazda dealership, if you have a couple of minutes, could you check in the parts department and see if they can cross reference a larger amp'd alternator for the protege'?

thanks

[Familia323]

yeah I wouldnt mind upgrading the alternator, if it means no more blinking headlights.. :D

[1sty]

They still will.
Put a 1 farad cap on each head lamp, no more blinking!
:D

[chuyler1]

Originally posted by 1st MP3 in NH
They still will.
Put a 1 farad cap on each head lamp, no more blinking!
:D
(lol)

[1sty]

Well the idea of stopping lights dimming by putting a cap on the amp is dumb. It will balance the voltage over the amp not the rest of the system. Hook a big ass cap to the head lamps I they will never dim, they might explode though!:D

[mazdadan]

Another thing that causes the flickering is the A/C compressor. If you have the selector on one of the two defrost modes, the A/C compressor will cycle on and off, causing the lights to flicker. I have also noticed that if I start my car at night and flip on the headlights, when I rev the engine they get brighter. Every Mazda I have owned has always had a weak alternator.

[scapamouche]

Not JUST the AC compressor. I almost NEVEr use my AC, but I also have the flicker.... it's the FANS!!! The radiator/intercooler fan assembly is VERY BIG AND VERY POWER HUNGRY. The starting surge when the fans turn on is the source of the flicker.

Quick electricity lesson: most electric motors have very low internal resisitance when first started, therefore they draw HUGE amounts of current (Ohm's law: Current (I)=Voltage(V)/Resistance(R) ) AS the motor comes up to speed, the internal resistance of the motor goes up (as counterelectromotive force is generated by the windings in the motor) and the current draw of the motor goes DOWN. In most big electric motors, a set of resistors are connected to the motor to reduce the cirrent draw during that startup period, then they are removed from the circuit.

On the MSP, those fans have NO starting resistors, so they draw LATS of current when starting. So much current, that added to the existing current load on the alternator, the capacity of the alt is exceeded, and the battery is drawn on as well. Since the battery supplies current in inverse proportion to the output voltage (in english: As current draw ^, voltage v ) therefore the voltage of the entire electrical system v therefore the lights get dimmer. As the fans get up to speed, that excess current draw goes away, and the alternator can keep up, and voltage returns to normal.

Was that detailed enuff? ;) This sort of thing is my job, so i can pontificate ad nauseum....

[SOSPEED]

hey scapamouche can we put resistors in ourself then???

[ARunto]

mine flickers too...buy some HID's and they won't flicker ;)

[BremertonMSP]

Originally posted by SOSPEED
hey scapamouche can we put resistors in ourself then???

No, the point scapamouche was making about the resistors where that they are only in the circuit at startup, to limit initial current draw. Unless you build a circuit that automatically removes the resistors after the initial current draw, they will limit the current to the fans all the time. More of a hassle then it's worth to me.

As far as the A/C goes, that's more of a mechanical load on the engine when the compressor engages. Sure the electric clutch draws a load when engauging the clutch, but the main annoyance is the electric fans. For some reason, this problem just annoys me to no end. I had a 94 Probe (a re-skinned Mazda) with a 2.0L motor and never had with problem with flickering lights. Maybe I’ll have to see what kind of alt they used in that car.

I’ll keep looking, I’m going to get to the root of this problem and get it fixed, or go nuts trying.

[scapamouche]

ARunto: I doubt HIDs will help. In fact, I'd wouldn't be surprised if guys who put HIDs on MSPs (Yup, I'm in the Navy.... love those acronyms ;) ) end up with SHORTER bulb lives than they should get because of the voltage spiking. HIDs DON'T like having their voltage changed...

[Gbourdon]

I just searched and found this have there been any simple fixes to this problem. The powerwindow will make the lights dim the headlights flicker whenever the fan comes on but what the hell. It doesn't really bother me that much. I just don't want to loose my headlights because of a lousy ground or a poor connection.

[ARunto]

GB...it all comes down to the alternator.

[MSPDAVE125]

Mine flickered too. I leave my vent selection on the dash board.

The flickering has ceased. The a/c AUTOMATICALLY turns on when in the windshield defrost position or the feet position and the blower is on.

There is a thread somewhere here that describes how to re-wire the A/C controls so you can control the a/c with the button Mazda provided. I plan on re-wiring mine over the winter.

Try leaving your vent settings on the dash (all the way to the right on the dial) OR don't turn the blower passed "0".

All new cars have these Variable Cycle Compressors. I was wondering why my gas mileage sucked until I discovered this a/c thing. My hesitation also calmed down when I stopped using the defrost setting.

Find the thread....Re-wire it. And once again solve an MSP mystery.

[servoeyes]

The alternator is fine, just upgrade the wiring from battery to alternator. The dimming lights are well explained by scapamouche...beyond that it's the stereo's draw on the system, which, when stock, is minimal. My concern is the dimming of the interior lights...I'm not sure how to remedy this. I think a CAP on my system would help in that regard, but other than that, I'm not sure what would...

[MSPDAVE125]

Originally posted by BremertonMSP
No, the point scapamouche was making about the resistors where that they are only in the circuit at startup, to limit initial current draw. Unless you build a circuit that automatically removes the resistors after the initial current draw, they will limit the current to the fans all the time. More of a hassle then it's worth to me.

As far as the A/C goes, that's more of a mechanical load on the engine when the compressor engages. Sure the electric clutch draws a load when engauging the clutch, but the main annoyance is the electric fans. For some reason, this problem just annoys me to no end. I had a 94 Probe (a re-skinned Mazda) with a 2.0L motor and never had with problem with flickering lights. Maybe I’ll have to see what kind of alt they used in that car.

I’ll keep looking, I’m going to get to the root of this problem and get it fixed, or go nuts trying.

Your right. The fans are what draw the amps away from the lights.

My concern is that the a/c fan kicks in when the compressor does.

Test it out. Use the dash vents and press the a/c button. Both compressor and fan engage automatically. (At least on my car they do.)

That is why I'm going to re -wire it.

[ARunto]

what's the guage on the OEM wiring of teh alternator?

[servoeyes]

two either 8 or 10 gauge, I believe. I was told to replace then with 4 (easiest) or 0/1 (which even 1st had trouble routing...)

[CarlM2]

Originally posted by MSPDAVE125
Your right. The fans are what draw the amps away from the lights.

My concern is that the a/c fan kicks in when the compressor does.

Test it out. Use the dash vents and press the a/c button. Both compressor and fan engage automatically. (At least on my car they do.)

That is why I'm going to re -wire it.

Mine dim on the highway going 60+m.p.h. in cool weather. It's worse when the A/C compressor is cycling but, why would fans be coming on at any speed above 20 or so? Seems like they'd prohibit flow more than help it.

BTW, I asked the dealer to check it out when I was at the dealer and they said it checked out OK, good amperage, etc. But, that when the A/C is on, there is a signifigant draw and the dimming is a side effect... but, it's operating as intended.

[BremertonMSP]

Originally posted by CarlM2
Mine dim on the highway going 60+m.p.h. in cool weather. It's worse when the A/C compressor is cycling but, why would fans be coming on at any speed above 20 or so? Seems like they'd prohibit flow more than help it.

That's the big question, why are the fans coming on when you're cruising down the h/w at 75 mph? This is the first car I've ever owned that did this. My 94 Probe didn't do this, my 03 PR5 did, as well as my MSP.

I wonder if the non-a/c'd protege's do this. I'm also curious if they have two fans. I'm half tempted to put a kill switch on the fan power lines so they don't come on while driving at speed.

I've also noticed that while accelerating, if the fans kick on, you can feel it in the delivery of power. Just one more thing to add to the list of things that rob power.

[Familia323]

I think someone talked about the fan thing before and the fan only comes on when you have either your A/C on, the defroster on, or the settings where air is sent to the lower vents of the car.... so basically if you dont want them to come on use the vent option that blows straight out at you....

[Tex]

My car would even do a "shudder" that could be felt throughout the car if I was sitting at a light and the fans came on. Feels like the motor dies for a split second, then comes back to life. I had a dealer check it out, and they said the fans were drawing proper amperage when they cycled on. My lights flicker at night too when the fans cycle on. If this is the intended operation, it's a piss poor design.