Roadmaster Wagon battery/alternator issue - please help

[RogerSterling]

Hello,

I have a '94 Roadmaster Wagon with 131k miles on it. For the most part, everything on the car runs great, but I've been having an issue I was looking for some help on.

Sometimes at stop lights or right after starting the car, the headlights will dim...then come back to normal...then dim...then come back to normal...all for a few minutes. This is accompanied by alternating high/low revs while the car's in park. Worse, once while at a stop light, the stalled completely and I had to restart it. Right before it shut down, the "VOLTS" and "OIL" lamps turned on. I was able to restart the car and it drove fine for the rest of that trip.

Is this an alternator issue? Just a bad battery? Or something else? The car starts up fine even after sitting for several days, and I've never had to jump it.

One last thing - a few weeks ago I had taken it into a mechanic where he repaired a vacuum hose and replaced the map sensor. I don't think this would be related to the current issue, but just FYI.

Thanks in advance for your tips!

 

[MelsRegal]

You need a voltmeter to test the charging system and battery.
How old is the battery?
Have you checked the battery connections for lack of corrosion and if the connection is tight?

 

[Bigpower]

I know this post was from a month ago and the OP may have fixed the problem already, but here's what I've done recently to my 94 with dimming issues. Check the ground wire from the negative terminal to the fender. The previous owner decided it wasn't necessary....yea right. I ended up making 2 short leads out of 10awg, crimped rings on and shrink tubed. Next sanded the area where it bolts to the fender and wallah, no more dimming lights, turn signals don't slow down under heavy electrical load. I also went thru and made a couple more wires for another engine to body, engine to frame grounds. Anytime there is a dimming problem, the grounds are the first place to look on a 25 yr old car