93' RS Drained a new battery and dies suddenly at stops.

Hello all.

My 93' RS all of a sudden started dyeing on me at random stops. Replaced the battery thinking this would fix but she just drained the battery after the initial ride. I can push start but the battery doesn't seem to charge and still dies at stops.
Alternator maybe?

Thanks,
Kerbse

I think your first guess is bang on. Just remember if you test it, you may have voltage but not amperage. If one phase of the rectifier goes bad, an alternator can still create voltage but your amperage is about 25% of normal, usually just enough to keep the engine working and the lights but not enough to charge the battery.

How long has it been since the alternator belt was replaced? Recommended interval is 36,000 miles, and they can deteriorate and/or slip before that.
And if it's time to R&R the belt, it's worthwhile to upgrade the pulleys there to accept the "newer style" of belt.

Possibly there is actually some other new drain sucking down your battery. Put an ammeter in series with either battery terminal and start pulling fuses one at a time (engine off, key on) - if there is a significant drop in current, you may have found a potential issue. The clock only draws a few milliamps; I don't know what the computer, injection, or ignition draw in a static condition, but I'm sure others can contribute here.

What "newer" style of belt? The stock original spec belt on my 94 RS works fine. My RS had the recall to replace the aluminum pulley with the stronger steel one, back in 95. Since then I have replaced the belt once in 172,000 miles. Alternator works fine, always has. I still carry an extra Dayco belt that matches the stock belt incase I need to replace some where on the road.

ANDYVH said:

What "newer" style of belt?

Click to expand...

ELAST, see Anton's discussion here.

Thank you for the link!

dbrick said:

ELAST, see Anton's discussion here.

Click to expand...

Thank you for the link!