alternator at 18 Volts???
 

brought my car in for a fluctuating idle , my tech says that the alternator is cranking out 18volts and he needs to change it just to start (also thinks that may be the cause). alternator + overvoltage relay + labor = $500. first of all, 18 volts IS out of whack right??? i do trust my guy but thought i'd check with old reliable techs here...

Check your battery ground cable make sure its tight and clean.....

if not you need a new regulator...

THe alternator can and will deliver 18v if the regulator is bad.....thats from personal experience. And 18v will do a lot of very bad things to the electronics in the car.

That is correct, the price is about right for a shop to do the work, get it fixed ASAP

does it mean the alternator needs changing too though?

Lot cheaper to change the regulator and lot less labor, as you do not even have to take the alt off.. If the alt is capable of 18v output , it is a decent alt, but the output is just not being regulated.
As far as OVP goes , the high V may have just blown the fuse on top of it..might want to check that before changing that part too.

.. not saying they are wromg, just advising you look at these first...

Arthur is exactly right on this. A voltage regulator can be had for less than $20 and is all you need in this case. It can be changed in 10 minutes.

Good luck,

thanks all, specially resident gurus. i guess it's the price i have to pay for having an all consuming job that pays the bills but keeps me from tinkering with my car... :o

I hear you, brother! I'm back to living out of a suitcase Monday-Friday until September. It pays the bills, but sometimes I have to be reminded where home is...

My SDL is a rolling collection of "gonna do's" since it's hard to do DIY work in a Red Roof parking lot, and when I get home I'd rather spend time with the family than the car. I have done some minor work in the parking lot, but the toolbox is a loooog ways away... :D

Best Regards,
Jim

You may not be able to swap out the reg on your alternator...I had to get a reman (about $250 back then) when mine went out.

I too measured 17.5V. In my case, the battery was venting, and I could smell (and feel in my eyes) the acid in the air as I drove.

The next step would have been the battery exploding! Fortunately, I stopped driving it that day until I could swap out the alternator...

<<You may not be able to swap out the reg on your alternator...I had to get a reman (about $250 back then) when mine went out.
>>

That may be correct.. I noticed Fastlane has Reg for previous year and subsquent year, but no 1993 listed .. might want to call a Benz Parts dept.. might be a typo, or they just did not have a sep. reg. that one year..
??????????????

Thats why I held off saying to just get a regulator...not being familiar with his year and model to know if they are like the early ones or not.

If its doable its an easy fix...if not he needs ot swap the whole thing...but the root of the problem is the regulator.

I have yet to see a 124 or 123 alt that does not have a replacable regulator. It could be that in some cases a rebuilder rivets the regulator in place. In which case you should be able to replace it using screws.

Good luck,

I agree... I think Fastlane just does not have a full listing as that chassis was only made for 1 year.
Benz has them @ $29.30 for that chassis
Bosch part BSH058726
So, change it out and save yourself some big $$$$$$$$'s