[hawkhopper]

Hello, first post! :chili:
I have a generic problem that I suspect is the voltage regulator but figured since I was here to ask it anyhow... problem:
While driving at night, the dash lights, the interior lights and driving lights all get brighter and dimmer as the engine idles. It get lets noticable while RPMs get higher but the volt meter doesnt work right and I just cant offord a new after market one right now. Could this be anything OTHER than the voltage regulator? maybe alternator trouble? How do I test to narrow the culprit down?
Thanks in advance!

 

[TheUnforgiven]

1.) go introduce yourself in appropriate forum. :thumbup

2.) Fill in your bronco info in your garage. or in your signature, like I do.

<---------garage, signature is at end of your post.

3.) the voltage regulator regulates how much voltage the alternator puts into the battery, to prevent the alternator from frying the batt. it does not regulate the voltage into the rest of the truck.

4.) Do you like sheep??

5.) Welcome to FSB. :beer

 

[hawkhopper]

I will introduce myself And I did update my profile... Guess I have some more work to do. However, any ideas as to why my lights would be dimming and getting brighter about 4 times a second?>

 

[TheUnforgiven]

sorry man, can't help ya there. Brian knows little about electrical :toothless

 

[FireFighterMike]

I have an 86 bronco..and mine does the same thing...the Tach. goes wild while i idle with my headlights on, and if i hit the defroster it pins itself all the way over, and i was kinda wondering what it was too.

And if you dont mind i have one question for you.... Why would you take one of the best looking years EVER for a Ford truck and put that front clip on it???? One of the biggest reasons I bought my Bronco was because of that awesome front end.

 

[hawkhopper]

It was like that when I got it. However, I dont all together hate it. I mean I have a 1983 Donor Bronco XLT I could take the clip off of but, I dont know... I mean its gonna be hidden anyhow once I put all of my bumper gaurds and lights on it. (Shrugs)

 

[95_G&W_XLT]

Bad diodes in the Alternator can cause the dimming and flickering, especially if you notice it more at high RPMs.. Get your alternator tested...and get your regulator tested.

 

[hawkhopper]

4.) Do you like sheep??

Why would you ask if I liked sheep? :wacko

 

[Seabronc]

1.) 3.) the voltage regulator regulates how much voltage the alternator puts into the battery, to prevent the alternator from frying the batt. it does not regulate the voltage into the rest of the truck.

The voltage regulator sets the output voltage level of the alternator no matter who is using the current it is supplying. Once an engine is running the alternator recharges the battery and supplies the total vehicle demand providing it is functioning properly.

It could be either the VR or Alternator. You can test to see if the alternator is putting out properly by removing the battery Negative lead once it is started. If the alternator is working properly it will keep the truck running as well as supply normal running load like lights. If it can't do that then change the VR first, It is the cheapest. The battery does nothing after the engine is running unless the alternator can't keep up with the current demand.

Note. I suggest the Negative lead is safer to remove since it doesn't present a shorting hazard that could wipe out other stuff. With the Negative lead off the battery can not supply current.