headlights and inside lights flickering at idle

[slackrtroy1014]

hey there first post on the forums, therangerstation.com has saved me several times before, thanks to all the knowledgeable people posting in the forums

found a super clean 88 bronco ii off craigslist, for once turned out being one of those great deals that actually is great, whole thing was almost rebuilt besides a few smaller things, my problem is is that lately when im at stop idling or not giving it gas the headlights and inside dash lights flicker, when i give it gas it seems to be fine
im gonna start with a new battery this weekend as this one looks somewhat old,
any other tips?



on another note it likes to idle at about 1000 rpm wich seems a little high to me, im also used to my older bone stock 2.3 ranger that didnt have a tach, radio or power steering

 

[strvger]

first, Welcome to TRS!

double check all the alternator, battery, and starter hot wires and grounds to make sure they are all tight. double check the alternator output before you replace the battery. take it your local auto store as most test them for free. and they'll test your battery at the same time.
when all that is done, you should know pretty well where the problem is and be able to get it fixed.
good luck with your new b2 !!!!!!

edit: my '83 2.8l is supposed to idle at about 900, so you are close. in the cold winters we get here, i prefer a little higher idle.

 

[slackrtroy1014]

thanks, whenever i finally get time off work (hopefully this weekend) im gonna stop up at autozone and get all that tested, just moved out to colorado from ohio, so tryin to get this thing ready for summer mountain trips

 

[slackrtroy1014]

ended up getting off early for once tonight, got the battery and alternator tested they were fine, but when i went to drive away the headlights were fine
so the problem seems to almost happen at random or when the motors still somewhat cold...
any other suggestions?

 

[Spott]

If you have a loose battery terminal clamp, the lights will flicker with vibration. If you have a weak battery (low water, old battery, sulfation, etc) the lights (and heater fan) will dim/slow when at low RPM and return to normal at medium to high RPM. The same can also be caused by a bad voltage regulator at the alternator.

You can check with a multitester, at the cigarette lighter plug: With the engine off, your battery should (ideally) supply 12.6 volts...anything over 11.8 is probably good (A low voltage at this point indicates a weak battery). With the engine idling, you should get approx 13.8v, and at high RPM you should also get 13.8v. If the voltage is low at idle, or quite high at high RPM, the problem is probably the regulator.

Let me know what you find,
Spott

 

[slackrtroy1014]

further investigation showed that the battery terminal wiggles a little bit and is slightly cracked around the terminal, going to replace that this weekend, hopefully thats all


thanks for the suggestions, that will be my next option if the new battery doesnt fix it

 

[strvger]

hope a new battery fixes it for you. i'd suggest one of those marine/staring batteries putting out close to 800 cca. it gives you those nice accessory posts with the wing nuts for when you start adding lights and stuff. that's what i have and it does very well for me. 5 years old and still starts without hesitation at -20! it's also a gel cell type.
good luck with it and let us know how it works out for you.

 

[slackrtroy1014]

well finally figured out that problem after driving up to denver, stopped at the skatepark for an hour came back, battery was toasted. rode my bike 2 miles to napa got a battery came back to put that in, realized the terminal clamp was the main cause for the flickering, for the negative there was a marine type teriminal clamp and it wasnt making full contact to the lower part, after wiggling it and seeing the reaction, replaced the clamp and now everythings great, besides the strange idle and lack of power when accelerating, replaced the iac, o2 sensor, inspected and cleaned the injectors, air intake needs cleaned a bit but that question is for a differant section so may post that tomorrow after i take a better look into it