On my 1980 300D my alternator fell off (beleive it!) while I was driving and I made it about 3 more miles. Finaly the battery ran out and there it rested.

After I put a new alternator in, I had somebody give me a jump start, but nothing happened. Except I must have had a short somewhere because the jumper cables started to melt! (Nothing happened to the car giving me a jump.)

I double checked the wiring and noticed a black wire comming off the solenoid should be attached to the positive battery terminal. So I attached it.

I attached jumper cables to it, it immediately attempted to start on its own! It only made a clicking sound, because the battery was not juiced up quite enough when it attempted to start, and the glow plugs were not warmed up, but it kept trying to start on its own, over and over, (click click click) untill I removed the jumper cables. What is going on?

Your car will run without a battery or alternator, all it needs is fuel to keep going.

John

greasemonkey,

I do not understand why your car stopped running after the battery ran out. As John pointed out, it should still run without battery. Something wrong with the engine?

The jumper cable started to melt. It was possibly because the starter cable came off the starter and it shorted to the body. But, how could this happen at the same time your alternate fell off. The cable should be attached to the solenoid with a nut tightly.

I assume that you found a new nut and put the starter cable back to the right place. Then, the starter was making clicking sound. The clicking sound was easy to explain because your battery was very low pulling down the voltage when a jumper cable was attached. You want to be sure the jumper cable has a good contact at the battery terminals and let the donor car charge your car's battery for 10 to 30 minutes before turning the key to start the engine.

Reading your post again, it seemed to me that your starter attempted to start the car by itself without you turning the key. If this was true, your starter had a problem, either the solenoid stuck engaged or the black cable to the starter somehow touching the small ignition terminal nearby causing the engagement. Check the starter cable again, make sure it is attached to the starter's big terminal only, not touching anything else.


David

So it turns out, I didn't need a new starter. The black wire I mentioned was not even supposed to be on my car, I guess the previous owner put it there, who knows?

So I took it off and it was causing the short from the battery to my starter, it worked fine after that!

This one has me mystified. When your alternator fell off, didn't your car overheat? It would seem to me your water pump would stop working as the fan belt that drives the water pump also runs the alternator. If the alternator fell off what kept the fan belt in place?

Also, how and when did the black wire appear? While the problem seems to be related to the alternator incident as you have relayed the sequence of events, I do not see the connection. If it was there from the previous owner, how did it not short out earlier?

If the engine overheated you may have been lucky to get it running again at all. I had a 1967 250SE for a while (actually my wife's car before we got married) and her brother took it to Florida in the early '80s. Along the way the water pump died, and he drove it back by running until the temperature got real high, then stopping and filling it with water (nice guy - could have put a water pump in but elected to run back this way because water was free). By the time he got it back to me the temp guage was fried, and the head gasket was shot. I rebuilt the head and got the car running good again, when he borrowed the car again. This time a hose broke in the winter, and all the radiator fluid came out, the car overheated and the engine stopped. He called and told me he thought it was siezed as he could not get it to turn over. I went to pick the car up, and tow it home, but tried starting it first. Well, after sitting for a few days, with the battery from my 1974 240D hooked up to it, it cranked over and started. I drove it home and it did not seem worse for the experience. My wife traded it in on a Honda Accord shortly thereafter as it was a little on the large side for her taste.

Anyway, it is not clear to me what your original problem was, as the car should run with the battery unhooked once it is running. So there is no "electrical" explanation for what you experienced. And no reason why the black wire was ok before the alternator fell out, and not ok afterwards. Good luck, Jim

__________________
Own:
1986 Euro 190E 2.3-16 (291,000 miles),
1998 E300D TurboDiesel, 231,000 miles -purchased with 45,000,
1988 300E 5-speed 252,000 miles,
1983 240D 4-speed, purchased w/136,000, now with 222,000 miles.
2009 ML320CDI Bluetec, 89,000 miles

Owned:
1971 220D (250,000 miles plus, sold to father-in-law),
1975 240D (245,000 miles - died of body rot),
1991 350SD (176,560 miles, weakest Benz I have owned),
1999 C230 Sport (45,400 miles),
1982 240D (321,000 miles, put to sleep)

Your'e right, it did start to overheat. I could also hear the belt (zzzzzzzzzzzz) rubbing against probably the other belt. When the alternator fell off, it yanked the attached wires pretty good and they were severed. I had to locate a replacement plug-thing that attaches the wires onto the new alternator. I also had to find a replacement alternator pulley, they dont come with new alternators, your supposed to get the pulley off the core, and mine was on the side of the freeway somewhere!

Anyhow, the severed wire on my car (except for the thinner, blue wire) were both red, and the respective wires attached to the replacement plug-thing were both white (except for the thinner blue wire, which I attached to the blue wire on my car, of course)! So I figured I had a 50/50 chance of connecting the correct wires. I may not have because while troubleshooting the wires were switched a couple of times, and jump starts were attempted several times, perhaps with the incorrect wires attached. This may have cause a short, I'm not sure, but whatever the case, there was a short somehwere at some time because what happended was, when the wires got too hot, it melted the rubber off of the black wire that I eventually removed, and when it was exposed, it started to melt the rubber to the wires attached to the starter. So then those wires were exposed and now all the wires were touching eachother.

Frustrated, I followed every sigle wire comming from the alternator, and the starter, and the battery. Because the voltage reader of course detected a charge, because there were no breaks in the curcut. When I found the exposed, shorted wires, I removed the black one, and re-insulated the rest of the wires, and gave it a jump, Ta DA! My 300D started and ran like normal.

I lost the pulley on my '83 300D on the highway awhile back. No charging/main water pump. Engine kept running of course. Only water circulation was from aux. water pump for heater. Car ran real hot with a bit of boiling. Now the fun part: I drove the car for over 50 miles that way on the expressway-65+ mph. Car seemed ok on highway, but ran hotter in town. Drove to a rental place and finally shut down motor. Towed car home next day on tandem trailer. Replaced pulley and belts (they had just hung loose on crank pulley). Car started and ran fine. That was almost two years ago and car still runs fine. Only thing to go was aux. water pump. Motor is open. This car is incredible. Will become my 16 year old daughters car in a few weeks.
BobK.

Currently:
'83 300D
'86 190E
'87 560SEL
'93 K2500 Suburban

I lost an alternator belt on the Interstate about ten miles from Hope, Arkansas about five years ago. I drove on into Hope, got a belt, took it apart on the auto supply parking lot, put on the belt, made the obligatory Bill Clinton/Hope Arkansas jokes and ended up only ten minutes late to my meeting in Little Rock. Not long after that I gave IT to my oldest on his 16th. birthday.

On the road it works out okay because the fan "windmills" to circulate enough coolant.

BTW Both of my kids ended up with a 123 diesel on their 16th. birthdays. They are a great first car for a teenager.

Have a great day,