Just installed the 143 Amp on 1989 300CE
 

Thanks for the mod information. I just installed a 143A alternator on my 1989 300CE and it works great. I can run my heater blower, defrost, headlights, stereo at idle no problem. I ended up two strands of 4ga wire 60" long with one strand 16ga as recommended. Using the stock distribution block was easy; I placed one 4ga wire on each of the two posts. The pulleys were easily switched using an impact wrench as previously mentioned.

Great mod, purchased the alternator on ebay for 115. Wire and terminals cost me $40 at a local stereo store. Took approx 3 hours of work to prepare then install, and I changed the serpentine belt as well.

Thanks again for the information!

This upgrade would sure be great on my w210. The defroster drops voltage. I think my stock alt is rated for 70 or so amps. WEEAAKK!

Hardcharger, glad to hear your upgrade went smoothly! :)

michakaveli, the same upgrade should work on your W210 also...

:balloon2:

followup
 

An old, old thread. Just wanted to give an update. I had my mechanic perform the 143a alternator "upgrade" to my '89 300CE about six or seven years ago now. Can't remember exactly because it has been working flawlessly since being done. No issues at all...absolutely none! Can't remember if the cable was replaced or not. I'd have to check the mechanic work order.

Same here. I've had the 150A upgrade on my cars for years now, with zero problems.

:scholar:

Will this work
 

I think I've found a 123 drop in upgrade.
Here's the background. Somehow, the bottom mounting bolt in my 83 300D-T broke but did not fall out. In changing belts, I found the problem but it had grown into a bigger issue. The broken bolt had vibrated around enough to make the alternator and the engine mounted bracket out of round and therefore hard to hold in alignment. It's still holding but I went to PNP for the 1/2 Labor Day sale.

I found an 84 300D-T with a good bracket and an alternator that didn't turn as freely as I thought it should (but I could use the parts to fix mine). I kept searching and found a recently rebuilt Bosch alternator in a 1984 500SEL. 137 amp with the same dual V belt pulley as mine and the donor 84. I bought it all (bracket and two alternators for $42.49 (including all fees and taxes). I've not installed it but I did do a test fit into the mounting bracket I pulled - exact fit. It measures 3/8" deeper so I may have to rotate the back to make it clear the AC hose, etc. Looks like the same pully but I'll take some better measurements before installation. Got to wait on some more free time to do the work. I did find that Eagle offers rebuilt alternators up to 150 amp for the 123's.

Any reasons not to proceed as long as I increase the wire sizes?
Any other recommendations?

I have been running a 150amp alternator in my 300TE thanks to Dave for about 3 months now.


Cranks out 13.4 volts with everything on, and stereo blaring.

Thanks!

I have a Saab 115amp alternator in my 83 CD with 4 large amps @330 watts RMS each and I have no trouble burning up my passengers hearing.

Will this alternator fit on a 190D?? Thanks

Yes. You may need to re-clock the alternator (depending on what donor you use), and you will need to swap pulleys (use the one on your original alternator). And of course upgade the wiring, etc. All of the serpentine-belt alternators will interchange through about 2001 model year... after that, they switched to a different 2-wire voltage regulator.

:chinese2:

"YES" :eek: I will be going for the upgrade Thanks gsxr

FWIW, I did the 150A swap on my 603 Diesel a while back, works fine. Also installed it on my 300SEL.

I am talking years ago.

I have had a 143 on my 87 300DT 5-speed since I built it three years ago. I upgraded the cable and am powering an amp and two veggie oil heaters and an electric fuel pump without any trouble. I am planning to upgrade the headlights at some point too.

Finally upgrades to 143 amp alternator. Ran a #2 ground to alternator bolt and 2 #6 to alternator output. and a # 10 to the for the small wire. All terminal ends are soldered on.

I can idle with headlights on high , fog lights on after-market driving lights on and my Fluke meter reads 13.98 volts. What an amazing upgrade.

So in upgrading my 88 300ce alternator there are three wires on the back of my stock alt and the new 110-120 amp e420 alt has a b+ and a D+. Where do the two larger of my stock wires go and where does the little wire go? Thanks.