The great throbbing brain of GRM is needed!
1995 Legacy. 2.2l manual. 158k miles. Abs light comes on, then speedo and tach go to zero but car keeps running. Turn off the headlights and blower and the speedo and tach come back on and car runs fine. With headlights and blower turned on the engine is super sluggish. Turn 'em off, and it revs to red line no problem. Starter turns over slow but it does start.
I bought the car almost six years ago and haven't touched the battery or alt since. Could one of those be the culprit? Oh, great throbbing brain of GRM, steer me to the right answer!
jstand
New Reader
5/10/11 8:12 p.m.
Not knowing how long this has been going on, my initial reaction is the alternator. Although a cleaning and inspection of the battery cables wouldn't be a bad idea before buying any parts.
It sounds like the alternator is not able to keep up with the draw of charging the battery, powering the ignition, and any lights or accessories.
Anytime you put too much draw on it the voltage drops messing up the instrument panel and causing weak spark leading to the sluggish performance.
To be sure bring the old alternator and you battery to the part store when you go to buy the new alternator. They should be able to test both and confirm the diagnosis.
The only time i've had a battery cause problems like you describe is when I had a broken plate shorting out inside the battery.
I've had a vaguely similar problem in 2 different cars that I owned, a '79 Mercury Zepher and a '82 Pontiac J2000. In both cases, taking the car to a "repair" shop was all but pointless, as no one could duplicate the problem....or so they said. But when the Pontiac's alternator was disassembled at the dealership they discovered it was "toast". I'd say alternator, but I've never seen a battery last 6 years in any car, you may need both, eventually.
get access to a load tester. see if it happens with the load applied and the battery disconnected.
at 6 yrs old, I'd replace the battery as a matter of preventative maintenance. though FWIW, I don't recall ever replacing our subaru's battery from new.
Sound's like my Legacy when the alt is on it's way out.
