Dimming lights

[jaimico]

Hello guys, I´m having a dimming problem with my head ligths and fogs when the car is running in idle, I have notice that it comes and goes.

When I step on the gas, just a little, they will go back to normal, I have already check al connectors and wiring, the alternator is charging normal, and no issues so far.

But it´s funny that it comes and goes, any ideas? :iono:

[CTScott]

That is somewhat normal.

The headlights and fogs together draw about 18 Amps, which is a significant load on a 70 Amp alternator. The alternator reaches its 70A output capacity at about 3500 RPM, so at idle it is on the lower end of its curve. The battery acts as a reserve during times when the alternator is not keeping up with the system demand. If the dimming is significant, the next thing to check would be the condition of your battery. If it is reaching the end of its useful life, its capacity will be reduced.

[Klink10]

Mine does the same thing. CT would probably have a better explanation. I attribute it to the little alternator not keeping up with demand during certain moments. I know that if I put the car on the charger overnite to keep the battery up to speed, it doesn't occur as much.

Edit: He beat me to it.

[Bluevitz-rs]

Hello guys, I´m having a dimming problem with my head ligths and fogs when the car is running in idle, I have notice that it comes and goes.

When I step on the gas, just a little, they will go back to normal, I have already check al connectors and wiring, the alternator is charging normal, and no issues so far.

But it´s funny that it comes and goes, any ideas? :iono:

Mine used to do this very badly for almost 2 years.... until the car wouldn't start one day after diving it for more than an hour prior to trying. After I replaced the battery from my other car in storage (even though the battery is almost 9 years old, it rarely was used and was always fully charged) the problem has gone away.

[jaimico]

Well my batery is about a year old, so is not the batery, I guess the best option is to get a higer amp alternator, so it will not be that much of a problem.
Would a voltage stabilizer help in this situation?

[CTScott]

Well my batery is about a year old, so is not the batery, I guess the best option is to get a higer amp alternator, so it will not be that much of a problem.
Would a voltage stabilizer help in this situation?

The battery being not all that old doesn't necessarily mean that it is not the problem. Upgrading the alt would definitely help, but a voltage stabilizer would not.

[jaimico]

It´s funny, that one of the seling point for voltage stabilizer is "no more dimming ligths", that´s more marketing than real deal.

[CTScott]

It´s funny, that one of the seling point for voltage stabilizer is "no more dimming ligths", that´s more marketing than real deal.

A voltage stabilizer is really just a capacitor, and that is actually what your battery is as well, so it would flatten the sags a bit and might make the dimming less apparent.

[Klink10]

Simple things like ensuring connections are tight, free of corrosion etc. go a long way also.

[1.5]

I was going to recommend a stabilizer as well. Or how about a bigger battery? Switch to HIDs too they draw less power.

[Bluevitz-rs]

^plus LED tails brakes running light, front runnin lights, LED fogs if you have em. I would have to say the lights draw the most power next to the blower fan.

[jaimico]

Yeah, HID, LEDs, and a capacitor for the sound system as well should help to.
I´m going to have check the batery, and re-check all connectors, and grounds too.
Good inputs.