Welcome to FTE.

Seeing as how the problem cleared after you closed the hood, I'd maybe put the radiator support, battery to body ground points on your suspect list. There is usually a smaller diameter/gauge ground wire coming from the battery B- cable, over to the vehicles radiator support & the front lights, horn, ect, ground point/s are usually at, or close by. So check those battery to body ground connections. They are most exposed to water, winter salt & other putrid things that don't help their electrical connections, so they need to be clean, bright & tight to make a good electrical connection.

Same for both battery post & cable connections, if they weren't removed & cleaned for recharging when the battery was run down.

Other thoughts crossed my mind, so I'll post them also.
Seeing as how you ran the battery down by leaving the lights on, it was probably nearly completely discharged, so right after the jump start did you have the battery recharged slowly, at say a 4-6 amp rate, so as not to over heat the plates & boil the electrolite, or did you just drive it to let the alternator recharge the battery at its high current charge rate????

If you just drove it, to let the alternator recharge the battery, that wasn't a good idea, as our alternator isn't designed to be a battery charger, its designed to quickly put back/top off, over a Short period of time, the high current charge taken out of a battery on a start, or to run lights, fans wiper motor, trailer lights ect & keep the battery charged while we're driving.

So if its trying to recharge a deeply, or flat/completely discherged battery at a high rate of charge, over a Long period of time, both can overheat from the high current over a long period, which neither is designed for & that'll over stress, weaken & shorten the life of both.

I know you said you haven't had any problems since, just giving a heads up for the coming cold weather high current stress starts from the battery & recharge load expected from the alternator, when the alternator will be expected to be able to quickly top off the battery & is when either may lay down on you if they've been over stressed & weakened. If the battery is 4 or more years old or older & your in cold country, even more reason to have the system checked out.

So when you get the headlight problem fixed, consider taking the time to run this puppy by your favorite autoparts store for a no cost, under load, electrical system check up, with all electrical system components in the vehicle, via their portable electrical system tester.

Expertly used (so ask for their test guru), it can likely spot any weak components in the alternator, battery, battery cables, or their connections. If all checks out ok, consider yourself lucky, but at least taking the time to do this, will likely see you through upcomming cold weather, when over stressed weakened things like to give up the ghost at the worst time!!!

A bunch of thoughts for consideration. Let us know what you find.

 

You may want to also check the headlight switch to see if it looks like it has been heating up, this could also cause this type of an issue.

Tony

 

When I bought my 08' Ranger 4*2 in August 07', the warranty was 5 years/60,000 miles. I am assuming that you are out of warranty because you state that you are worried about cost. I had an alternator go bad on an 04' Ranger 4*4. The charging light on the dash came on, and my lights would dim briefly. All I can say is definitely have your charging system checked and go from there.

 

Thanks for all the suggestions. I decided to just take it in and be safe, don't want to risk getting stuck going to or from work. It was in fact the headlight switch. I'll be getting the truck back tomorrow so I'll now more about what they checked and didn't check. The part is costing $99 which is alright I guess, though it seems a little high.

 

1ATony called it right!!!!

Good feedback on your problem & to hear its fixed. Thanks for closing out your thread.

Did the faulty switch seem to have been overheating, or had you been having intermittent problems over time, like something smelling hot, or the lights flickering or seeming to be dim????

 

$99 really doesn't seem to be all that bad for a dealer part. I had forgotten that Rangers had headlight switch problems dating back to 02', I believe. Some later models were affected because of different suppliers making the same part. Either way, glad that the problem was taken care of.