"Well there is your problem right there" 240 ALT grey market

[rjz5400]

so as the name implies i have a problem with the alternator on my euro 240d.
it doesnt charge, i have a battery that is very new and appropriately sized so i cleaned the terminals, clamps, removed the strap and sanded the fender and then greased it all up and reassembled.
would start this morning.

so i charge it for a half hour it fires up and i drive it to the auto store to double check my assumptions. Sure enough he says charging problem.

so here it is, i take of the two service items on the back just to see if it is a no brainer (sometimes a broken or corroded connector) and i find this

full of sand it looks like, mixed with sugar or some binding agent oil? grease? who knows.
possible explanations.
1. ants
2. blown in through the alt during normal operation
3. odd french electrical protection crystals
4. god doesn't want me to drive this car across mexico in a few weeks and has filled it with "Manna" or some other bibley substance

i looked for my alt for parts and can only find bosh parts but mine says mottorolla and made in france on it.

anyone know either what this stuff is or where to find a new VR?

i am planning on scraping and cleaning it out but with what? starting fluid? degreaser? i dont have any dielectric cleaner but starting fluid is mostly ether so........


any suggestions ?

[rjz5400]

i definitely detected the smell of antifreeze in there when removing this material.

i had/have a small leak so could this explain it getting in there and gumming up some kind of desiccant?

[Diesel911]

NAPA used to sell Motorola Parts. At least they did back in 1989.

You never mentioned if your Charging Light was glowing red or not.

Is there any sort of part number on the Regulator?

[Diesel911]

This won't help much but I will post anyway:Motorola Alternator for Mercedes Benz
Motorola Alternator for Mercedes Benz

Where I have seen Motorola Alternators is on industrial Vehicles like Fork Lifts and Loaders. The last place I worked as a Mechanic was a place that serviced Carrier Refrigeration stuff; including the Diesel Gensets that powered the Refers Units on Trucks or Containers.
The 3 Cylinder Air Cooled ones had Motorola Alternators but they had the ones with the External Regulators.
When we needed a new Regulator we most often bought them from NAPA.

[rjz5400]

yea, the charging light never came on, just the dead battery or the slow turning over that i thought was a bad ground but apparently not.

i put a decent multimeter on it and it was jumpy and low. it read 12.4 12.9 12.3 13.21 13.1 12.5 13.22 13.35 12.7 ect.

i think it was weakly and intermittently charging.

yea there is a motor rebuild shop over by the river where the trucks and equipment roll through. i bought parts from them to rebuild my leese nevile 120 or 160 amp alternator for my bus so for sure they have or could get a reg for this alt.


i am hoping someone had seen this material before but thanks for the links. i cleaned it out pretty well and i am going to put it back on and see what kind of output i get.

there is a part number i will copy that and carry it over to napa or the industrial electronics rebuilder tomorrow if a simple cleaning doesn't do it

[rjz5400]

ok so i hooked it all back up and started it, kinda same thing accept consistent 13.5 at idle and it goes DOWN to 12.7 at like 2000 rpm.
is it possible that because the battery was not fully charged, it is reading low and will return once the battery has gotten back to a normal level of charge?
should i hook it up to the battery charger and then test again?

[79Mercy]

Still sounds like a bad regulator on that rare alt, voltage should increase with RPMs. If i were you i would just install a 65amp Bosch alt and be done with it, its a plug and play operation.

[Diesel911]

The Battery needs to be fully charged to get a decent test.

With all of the grit inside what did the Brushes and the Slip Ring look like?

[patbob]

Originally Posted by rjz5400

ok so i hooked it all back up and started it, kinda same thing accept consistent 13.5 at idle and it goes DOWN to 12.7 at like 2000 rpm.

Charge it up and retest. The voltage should not go down when you rev the engine. If it still does, then there's still something wrong, the most important result of which being that the battery won't be charging at speed :O

Like others have said, it seems like an awful lot of trouble to go through to avoid replacing that oddball alternator with a US-available part. Hit a junkyard if need be.

[rjz5400]

well. it sort of goes against my general philosopy to throw something away because it doesnt work. especially if it is a simple swap of a VR or sautering in new brushes.

also i am broke as heck. and bosch reman is 140 at the place i can pick one up tomorrow (advance)

lastly my fiance just baught an identical euro 240 and as soon as i get back from mexico i am parking it for parts. so putting in a "new" remanufactured alternator is always the last result for many reasons.
i have plenty of time on my hands
i dont really have money
i dont need the "peace of mind" many people get from bolting in something that is shiny because i know it looked just like mine before the new regulator, brushes, a cleaning and possibly some milling or buffing of contacts.



OK i will charge it up tonight and check it again running in the morning. i will also pull out the brushes and check those out (on this one they are separate not like the bosch regulator, and i didnt pull them earlier)
if that doesnt shed some light i will probably take the whole alt off and roll it down to the alt shop and let them hook it up and spin it to rule some things out.


thanks for all the tips and that link to the other thread with a motorola Alt.

ill update with the results

[rjz5400]

i got 11.97 with no load so the battery was dead to start out with.
i have it on 10 amps charging for two hours, once it cools ill recheck the voltage no load, running, at cruise RPM, and at idle with full load (stereo high beams, fog, defroster)

[rjz5400]

charged her up and got 13.87 or so at idle, went down at revs. and with a full load went to 12.4 or so.
it could have been my imagination but i thought i detected a burning smell also. looks like i am making a visit to the alt shop in my pickup, and then i have to put it back together and get the tires swapped before i head on a road trip.

ahhhhh what timing i have. hopefully the shop or napa have the service parts and that fixes it.

[rjz5400]

Well i hate to admit it and even though the deflection on the belt seemed acceptable, it was the belt.
i know day one stuff. look at the rookie here. Man why when i hear hoofbeats do i think zebra?

anyway the alt guy said "works at idle and goes down? check the belt by pushing the fan with two fingers, if you can move it, it is the belt. "

sure enough i tightened it and got 13.5 at idle no load up to 14.2 at RPM and 12.6 or so at idle with full load up to 13.7 at RPM

[MS Fowler]

Don't feel too bad. At times we all jump ahead in our troubleshooting.

[rjz5400]

Thanks, bump for all the Zebra Listeners.

That car is now passed on to a buddy of mine who drives it hundreds of miles a week.......