What is wrong here? *Dimming headlights*

[rich52490 10+ year member]

Hey all, I have a problem. I have a 1994 Ford Explorer and am running about 1200W RMS on my stock electrical (95amp alternator, Exide Select Starting Battery). Now I don't have major voltage drop, (~15V idle) maybe .6V at the most. (~14.4 under load). However I still have a very noticeable headlight dim. I was wondering what you all would suggest to help fix the problem? Big 3 is a given that will be done over Christmas Break. But as far as a new battery or a larger alternator I am stumped? What would you suggest? Thanks

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[bikinpunk 10+ year member]

So, at the point of dimming, your battery shows 14.4v ?

 

[rich52490 10+ year member]

So, at the point of dimming, your battery shows 14.4v ?

Correct

 

[bikinpunk 10+ year member]

Correct

hmmmm. OEM lights, I'm assuming, correct? Nothing special about them?

I'm not a big electrical guy, but my first guess is that you're simply starving the alt... but I would imagine that battery would drop voltage, and surely your headlights don't need more than 14v to operate correctly.

I mean, we are talking about a short, but large, hit....

I'm kind of stumped. I'd like to know myself.

 

[Etac 10+ year member]

doesnt sound right.. even your voltage on idle seems a little high... with an 85 alt IMO - if you wanna try something quick.. ground your battery to the chasias with a 4-1 gauge wire

but im not that good with this part so i might be wrong

and 1200 watts defently seems like it should drop your voltage a little with that alt..

 

[kegan 10+ year member]

hmm that is wierd if your still at 14.4, check the wires? Maybe something is jiggling loose. but Id say the big 3 would take care of it.

 

[Johnny Drama 5,000+ posts]

14.4 you should have no dimming. Fords run at 13.8v IIRC. Sounds like your mesurements are off.

Last...Your 95 amp alternator is your choke down. If you have the big three done, either upgrade the alt or add more batteries.

 

[rich52490 10+ year member]

hmmmm. OEM lights, I'm assuming, correct? Nothing special about them?

Yes OEM stock, nothing really special other than they are high output.

14.4 you should have no dimming. Fords run at 13.8v IIRC. Sounds like your mesurements are off.

I think the voltage regulator could be going bad on the alt. I'm not sure if that has anything to do with it. 15V does sound high for a alternator though

 

[rich52490 10+ year member]

if you wanna try something quick.. ground your battery to the chasias with a 4-1 gauge wire

I thought the same, I used a piece of 2AWG to make a new battery to chassis ground, however it didn't help.

Edit: Thats why I had asked about the alternator and battery, I don't think the Big 3 alone will fix my problem //content.invisioncic.com/y282845/emoticons/frown.gif.a3531fa0534503350665a1e957861287.gif

 

[lostdaytomorrow 10+ year member]

Idling at 15v? Are you using a DMM, and where are you measuring voltage during the bass note?

 

[cjacks519]

This may sound crazy (and I'm not sure if it's been mentioned) ...but have you tried a capacitor?

 

[canadapettit 10+ year member]

This may sound crazy (and I'm not sure if it's been mentioned) ...but have you tried a capacitor?

You my friend have just said a bad word on here. People on here don't like to use caps as they are a band-aid on a bigger problem.

 

[Racerx250 10+ year member]

This may sound crazy (and I'm not sure if it's been mentioned) ...but have you tried a capacitor?

I see that is your first post. Ehh... prepare to meet the rest of the forum.

 

[Racerx250 10+ year member]

Im suprised that word isn't x-ed out like the word dam.

 

[budahbuddy803 10+ year member]

where and with what instruments are these voltage reading coming from?