1990 240DL with a dead battery and possibly more?

bsig · Post by **bsig** » 13 Feb 2012, 15:01

Hi,

I've done some searches on this site, read a few articles, but was wondering if there was anyone out there that could help set me on the right 'path'. My '90 240DL worked great for the last 10 years, but about a month ago i go to start it after being away for the weekend and I had a dead battery. I jumped it properly (first time in 10+ plus years i can remember doing this, let it sit to charge for 30 minutes, turned it off, and it started the next morning and for the rest of the week. I have a short commute of around 10 minutes so basically it started, took it to work, took it back after, rinse and repeat all week. The weekend comes up and I again dont drive it for a day, so go to start it on Monday for work and the battery is dead again.

So I jump it, it runs, but the next day it is dead again. I jump it, it runs, i drive it to work, but this time right before im about to hop on the freeway the engine dies and i have to coast into a gas station that was on my immediate right. I had read about some fuel pump issues so now im starting to get worried, but i turn the car off, turn it back on. It starts up fine, and i continue cautiously to work. The car then runs all week again only to die again over the weekend.

Now, since then I decided that it was time to buy a new car (Ive driven this for the last 12 years since highschool and my wife and i are now starting to think about starting a family so she dissapproved of the old beater i was driving). We bought a 2010 v50 but thats a story for another day. I have thrown my 240 on Craigslist and have arranged to sell it to a mother for her 17 yr old kid as a surf wagon. Im excited that someone will get to enjoy the car for another 100k miles.

Now, I want to try to narrow down these issues because im not some skeezy craigslist seller and because i just want to try to narrow it down. I took the battery connectors off, and took steel wool to the battery terminals to spiff them up, and then connected a battery charger for a day. I used my father in laws voltimeter and checked the battery as soon as we disconnected and it read 13.3V. We left the connectors off and let the battery sit over the weekend and checked it again sunday and it now read 12.5V.

I want to check for a parasite draw because i do have issues with the glove box staying shut and the issue of the car dying mid-drive twice (although always at lower rpms) makes me think it might be something other than an old battery. I think this is the same battery i bought for it 1o years ago so that makes for an easy explanation. But is there anything else here I am missing? My first thought was something to do with the alternator but im not sure what the exact steps are for checking that plus checking for a parasite draw. any help is much appreciated, but im really just looking for a checklist of what to do next. The car is basically already sold, i just want to cover my bases and not sell someone a lemon. THanks

Post by **regent** » 13 Feb 2012, 19:14

With the engine running and no load you should read 14.2V or more, if less then your Gen is not doing its job.
On these cars it is the brushes in the voltage regulator that wear out and it may work with reduced performance or start failing intermittently. In addition, with those short trips the battery does not get fully charged.
You can check for parasyte draw with a clamp-on meter, there should be no more than a couple hundred milliamps with everything off. If more, I would start by taking fuses out to find the culprit.
If I read correctly, you battery is a teenager, no? If so, I would change it before it leaves me stranded on the hwy
Hope this helps

bsig · Post by **bsig** » 13 Feb 2012, 21:26

Many thanks. I'll crank it in the morning and and see what the reading is but my gut is telling me it will be weak. And yes, it sounds like the old battery is the first thing to fix here and work from there. I'm no car pro but I like to get my hands dirty. Is the generator and voltage regulator you are referring to separate parts or parts of the alternator? Is this something I can inspect visually or is the assumption they need to be replaced and to verify with a shop. Thanks again

dmg4 · Post by **dmg4** » 13 Feb 2012, 21:37

Geeeze, if the battery is more than 10 years old, you're lucky the car starts at all. It would certainly be a pain in the bumm to an even greater degree in a cold climate.

You have an alternator, (a type of generator, but mechanically distinct from those found in 1950s cars); and the voltage regulator is a distinct part with a different function.

Replace the battery first. It's due, and the least expensive option. If the problem persists, you're ruled out the battery without having really wasted any money. If it goes away, consider whether you want to keep the car or the wife. You can fix things that are wrong with the car.

Post by **regent** » 14 Feb 2012, 10:30

The V-Regulator is part of the Alternator; it includes the brush holder. You can replace the V-Reg if your Alt is in good shape altogether (consider that bearings and collector rings wear out, pulley condition, electrical insulation , and in that line).

At this age you may be better of with a rebuilt Alt.