Good running 1992 wagon, B230, auto tranny with 225 miles. Check engine light came on today so when I got home I turned the car off and left the ignition on to check the OBD codes. It was running a little rich because I had the wrong MAF in for the day. THAT ain't my problem now, however. In my haste I forgot to shut off the ignition and went about other things.

Walking past the car this evening, I noticed all the warning lights were still on. Time elapsed - perhaps 6 hours. So I started her up and heard the squeal of the alternator belt(s). This had not been a problem before so I went for a short drive... and the squealing stopped after a few minutes. All the warning lights came back on though. Of course the belts had snapped. I quickly headed for home and shut her down before the temperature gauge hit the half way mark.

The water pump and alternator pulleys still turn with ease and without any noise, but I'm guessing that at start up the alternator wasn't turning.

Any idea what damage I may have caused by leaving the ignition on all that time?

I agree totally with Smitty.. added draw from the nearly dead battery, and previously worn out belts... If the alternator spins freely by hand, you should be fine with new belts.

Check belt alignment as said...

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-Matt I ♥ my ♂

I can't imagine any damage from leaving your ignition on - the only thing different from driving the same length of time is that if the engine was running, the battery would be continuously charged by the alternator.

What did happen, I suspect, is that you had more current drain then normal, with relays and your ECU energized, probably more. The belt squeal you heard was due to the added draw on the battery after startup; the alternator had a heavier load and your belt was probably pretty worn. The fact that it broke seems coincidental to me.

Since you have to replace the alternator belt, before you do, check to see if the alternator is loose in its mount bushings. If so, that will create a misalignment with the crank pulley which leads to premature belt wear, and squealing. If the the alternator is firm in its bushings, then lay a straightedge across the alternator pulley and the crank pulley to see if they are not just parallel, but in the same plane with each other. If not, then you need to dig into the alternator mounts to see what's causing the misalignment.

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In God We Trust. Everyone else, keep your hands where I can see them.

You guys nailed it and I'm back on the road with no other apparent damage. Thanks for the quick and accurate info. I hadn't considered that the weakened battery could be the culprit. In fact, I didn't even think of it as weakened. The starter kicked right in nice and strong after 6 hours of drain.



Thanks! / Jim

a weakened battery condition, which is to say discharged.. not a weakened battery. A typical car battery is probably in the range of 80 amp hour capacity. Lets say you leaving the ignition on, there was perhaps a 5 amp draw, and for 6 hours. Total 30 amp hours. So, your battery was probably at about 60%, which should still start the car fine.. as you discovered.

Now with the car running, it's probably drawing about 20 amps.. and you maybe have a 50amp alternator... that leaves 30amp to recharge the battery.. so, you have to run the car for an hour, the alternator working at peak, to fully recharge the battery. That's a lot of strain on weak belts. Especially if they were loose, slipping, and getting very, very hot.

My numbers may not be accurate, but it gives you an idea as to the simple math involved. It's actually a sign that your battery is probably in good shape.. that it holds it's charge well, and takes a charge well.

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-Matt I ♥ my ♂

One of the things I was going to do this winter while the wagon would be mostly parked was to replace all the belts. Got there a little sooner than I had expected as it turns out. Now they're all spanking new. One less project to consider. Next up: a new sound system. I yanked all the good stuff out of my '89 and it's just sitting there waiting.

On a side note - the local junkyard unloaded most of its steel recently and when I went there the other day it was so sad not to see a single 240 in the whole place. It may be weird to say this, but that got me a little emotional.

"On a side note - the local junkyard unloaded most of its steel recently and when I went there the other day it was so sad not to see a single 240 in the whole place. It may be weird to say this, but that got me a little emotional."

I don't think it is weird at all. My Brother in-law and I watched a 240 get crushed in a Portland OR. P-N-P. We both just stood there and watched in disbelief. It was very sad to witness that carnage.

Trevin
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89 244 and a project 87 245