I have a 1990 240 with about 180k on it, I'm the 3rd owner. Car is in great shape inside and out. Parked it like 6 months ago, and bought a '98 V70 to use as my daily driver (I drive about 90miles a day), and drive the 240 around occasionally. I've been driving the 240 less and less lately though.

Here's my issue: after the car has been sitting unused for about 24hrs, it won't crank or anything, but power locks/radio/lights work fine. Car will start right back up if the battery has just been charged, or if it has just been driven. There was this one time I drove it around, parked it, and when I went to start it about 6hrs later it turned over really slowly and then picked up speed and fired up. But if about 24hrs have elapsed, no crank, but accessory power is fine. Battery is new (5 months old). If I put a charger on it for 15 minutes or so, it will start fine, like the battery isn't low or anything.

Thoughts? Any tests I can/should do?

 

first, verify the charging circuit is working... fully charge the battery, disconnect the charger and wait an hour or two, use a volt meter to read the voltage of the battery, shoudl be like 12.6V or so, then start the car, and read it agian running, and it should be like 13.8-14.2V. if not, its time to dig into the alternator, the D+ circuit, etc.

if the alternator is working, but the battery is discharging overnight, then you've got a parasitic loss somewhere, something is staying on. put your multimeter in 10 amp mode (this usually requires moving the red wire to a different input AND selecting the amps mode on the selector dial), and with the car switched off, for every fuse { remove the fuse, put the amp meter across the fuse contacts, see if there's any more than a tiny current drain, replace the fuse } ... note that when you first hook up the ampmeter, you might get a momentary spike of current, thats not a problem, wait a few seconds for it to settle down... anything more than like 0.05 amps is a potential problem, but if its dying overnight, your drain is likely 1.0 amps or more.

IF you find a fused circuit with a heavy drain, then figure out what is on that fuse and track all those things down... things like trunk lights not switching off are the usual suspects.

 

Drive it to an auto parts store and let them tell you what the charging voltage is.

Or consider using something called a multimeter.

 

Oh no worries, I understand what a science fiction multimeter device is. I posted a menial drain issue here because it's not happening like they usually do.

Ps.What is electricity tho

 

Awesome thanks for the heads up. I was hoping someone would bring up a common culprit. Seems like so many issues are common ones (thankfully)! Put the battery on a slow cycle charge for the day. I'll let you know how it goes once I dig into it.

Thanks!

 

i have had batteries less than a week old fail internally so, it may not be the case that a relatively new battery is holding a charge (assuming the alternator is good).
as others have said check the charging circuit and battery by doing a load test on it. i think you need at least 9.5 volts under the starter load.
if it passes then look for the parasitic drain

 

I just want to thank you for the good post!

At the junkyard, they force you to wear goggles or a face shield, and hand you a battery tester on your way into the "Battery Shack". Hilarious.

 

they don't want you coming back looking like...

 

Haha! Ugh, 1 guy flips a battery up-side down, puts it on another battery, and ruins the battery shack for the rest of us.

 

Fixed! Battery was holding a charge when I removed it from the car. Load tests all looked good. So I turned my head towards a drain issue. Tested all the fuse points, no drainage there. So I figured it was a grounding issue under the hood somewhere.

Removed essentially all the grounds near/around the battery and starter. Spent like an hour cleaning contacts (sanding, spraying with contact cleaner) and reattaching. Car fired up fine when I put the battery back in, and it's been working great for the past couple days! Starts up, no hesitation. And for some reason my speedo works again.

Thanks all for the input! Wow, no more existing issues to look at on this 240. Odd. Time for a road trip i guess.

 

good news that it's fixed. i know that some guys with jettas have to install about nine MORE grounds than were put in by the factory to solve electrical gremlins so makes sense.