Just recently my lights dim (all of them- cluster, dome, headlights...) especially at idle... First I thought it was the alternator. I brought the core in and had it tested. They said it was shot, but could they be pulling my leg??? I replaced it with a reman. It still does the same thing now but not as bad it seems.... Could it be the battery too?? Please help! This vehicle is sucking money out of me; I just replaced the fuel pump last week too!!! $400!!!!! :banghead:
Thanks,
-Mike

sounds like your battery is undercharged. Put a charger on it overnight or get thebattery charged. Also running it like this too long if infact your battery is undercharged, will again damage your alternator

they can/do go hand in hand, an underchared battery puts to high of a load on the alternater killing it, running on the battery, then the alt gets changed and the high draw once again kills the alt

Reman alternators are not always good out of the box.

Run an Ultima and a larger (new, bigger amp) alternator and problem solved, unless you have some type of draw somewhere.

just a thought but, I have a post going on the electric seat and door locks not working. I pulled the circuit breaker in the fuse panel it was so hot it burned my finger on contact , used needle nose to get it out!! still ;havent dug into it to find the trouble. drawing over 20 amps!!! since i pulled the breaker I have noticed the the volt meter is rock steady. I bought this blazer used 3 years ago it has always had the volt meter pulsate periodically and i have notice the lights to dim on occasion. No more since I pulled the breaker. you might want to pull the breaker and see if your problem goes away. at this point I supect a wiring problem short under the drivers seat My brother in law had a blazer a few years back that the wiring harness rubbed throught on a sharp piece of steel under the drivers seat under the carpet.

Same problem, new batt and remanufactered altenator, lights running dim. You might want to check to see if your A/C compressor kicks on and off, mine was doing that and I had NO call for A/C what-so-ever (ambiant here is 6 Deg F) so that may drain your system.

if the defroster is on the a/c compressor should operate and cycle on an off as the a/c removes moisture from the air before it is heated to blow against the windshield. therefore it clears the glass faster.

How is it cranking ? sounds like short somewhere in that seat circuit . Do you have heated seats? Rob