Derek Likos

Hey guys, never posted on here but looking forward to your opinion, hopefully i can give you enough info on my situation. I have a 2006 clk 350 with 114k miles. Car randomly started going into limp mode, headlights turned off and car wouldnt go faster than 30mph. EIS and SRS light along with ABS light came on. Pulled over jump started it and ran great while still connected to other vehicle. Once off it broke down. Took my battery to autozone and was completely dead, charged it, put it back in and the car starts right up with no codes but now my check engine light is on. After charging it, I put my car into dyno mode, ignition in position 2 the Voltage was at 12.4. After starting, it idled at about 11.7, but i didn't drive it. Is that voltage correct for my car or is the altenator the problem?

Side note: car was in the shop before this for a month, i had to get a new ECU, Body Control Module and Coding done to re program my keys. Luckily I have a good mechanic who doesn't screw people over, otherwise i would have sold my car because Mercedes told me everything would be $3,800! $1400 later... the car ran great for 3 days until the story above happened. Anyone think they're related?

Racin_fool

Sounds like you have a faulty voltage regulator or a bad alternator.. Should be idling around 13.8-14.3 volts..

Derek Likos

Okay thats the conclusion I came too as well, just wanted a second opinion, my regular mechanic isn't in town so im taking it elsewhere and didn't want to get screwed over.

DangermouseCLK

or, after the other electrical work, it perhaps wasn't connected up properly again?

Yidney

It could still be the battery. 12.4 at rest is a bit too low, and 11.7 while running is way too low. What is it while actually cranking? It's hard to get a read in the second or two while it cranks - which is why they make voltage meters that record the high and low while the test is done, but if you watch close you can get a pretty good idea even with a cheapie meter that only gives an instantaneous read. But I agree you also need to get the alternator tested.

Rudeney

11.7v at idle is an indication that the alternator is not putting out. Often, it;s the voltage regulator module on the alternator that is bad. It can be replaced separately.

Derek Likos

Thanks, nice clk! How many miles? And have you had a lot of major issues? Thanks again.

Derek Likos

thanks! I'm getting it checked out next week, usually a DIY kinda guy but i just want to make sure that this is my only problem.

Derek Likos

Turns out it was only my altenator, deciding not to go cheap and just get a new bosch altenator. $500 later... so im hoping it's smooth sailing for me. Atleast for a little while.

Yidney

Just saw this. Thanks. 71k miles and zero issues of note. I just posted it for sale.