Original alternator and or VR was changed under warranty. Voltage flickered around a little bit of variation and the other day convenience features shut off. Only red battery light. No messages. Voltage at 11.4 car on. Tried the new VR and it only went up to 11.7 volts. So, I guess new Alternator is in order.


Haven't found any detailed DIY, some out there but not really complete or kinda vague.

Questions:

Is there any fuses I should check that could be blown? Is there a fuse for alternator or something related to battery or charging system?

Is it possible to remove the alternator on an E55 without draining the coolant from the radiator and removing those PITA MB hose clamps for the intercooler lines? How?

If I need to drain coolant, how do I bleed the cooling system? Same way you bleed the intercooler I'm assuming? Just want to be sure.

Alternator arrives in a few days, $165 bucks with core exchange from auto zone. I guess I'll swap my new Bosch VR onto the new remanufactured alternator. Sometimes tells me it won't have a Bosch VR on it.

Anyone have any tips for removal and installation of new alternator?


What I know already:

Disconnect both batteries, remove fan shroud, remove both serpentine belts.


Pictures would help, Thanks in advance.

 

I removed the double idler pulley, both belts, both intercooler hoses (with pliers), fan shroud, belly pans, drain the coolant in the right bottom corner of the radiator





Some fried electronics and a noisy bearing





New piece going the reverse way





Bleeding the intercooler lines is just connecting a clear hose to the lines and putting it in the expansion tank and connecting 12V (car battery or equivelant) to the pins on the pump and making it run. Just make sure to pinch the hose below the bleed nipple to about 80-90%. Use OEM coolant.

 

That's perfect! Removal of the double idler pulley is something I didn't know. Those are the kinds of things I need to know.

I am thinking about removing the screws for the intercooler hoses and see if that gives me enough play to wiggle out the alternator. If that doesn't go. I'll try to pinch the lines and remove the 2 intercooler hoses for minimum fluid loss.

Thank you papieye!!

 

My mechanic did it from the bottom, went much faster, but you nee a lift for that

 

I was wondering if that would work too, Thanks

How many volts does your car show off and on with the new alternator?

 

after removing the fan, I only pinched and disconnected that 1 hose right in front of the alternator. with that hose disconnected, you can wriggle the alternator out of there and install it with no problem. just take your time and at first looks impossible, but turn it this way and that way and you will see that is slides in there with no problem. didn't even have to refill with any coolant after I got done due to minimal loss of fluid from there! trust me, it can be done!!! those hoses are very flexible, just that one is the one in the way! after removal, you should have anywhere from 13.6 to 14.2 volts while idle and with car off should read above 12.4. make sure your battery is fully charged and/or get a new one if it fails the load test. good luck man!

 

Ok but, the dual idler pulley needs to come off right?

 

sorry about that, definitely will need to remove the idler pulleys, you need that room to remove it. take this time to look at the serpentine belt and will be a good time to replace if you haven't done it over last 50k miles??? I replaced both belts during this install. but yes, idler pulleys will be in the way, need to remove to r&r alternator. sorry about that!

 

Putting an autozone alternator in your car is just asking for trouble. The quality control behind their products is garbage. You will most likely be replacing it again or dealing with other issues caused by voltage spikes from a sub par alternator.

 

Think so? It said Bosch replacement and I planned on installing my new Bosch Voltage regulator onto the new alternator.

It will have to do. Because I already ordered and should be here tomorrow. We shall see. I will report back with results. Thanks

 

Well if it's bosch you have good chances. I thought you got the house brand. Bosch is pretty solid though

 

OK mission success. Installed the new alternator and swapped for the new Bosch Voltage Regulator. Volts a steady 13.8 volts. Thinking if I should remove the batteries and have them charged up again. (had to drive on battery power to my buddies shop a 15 minutes away.

Battery light still on the dash. Anyone know how to get rid of it?

Another strange thing, the AC won't blast all the way it only goes up to low power on the fan. Im thinking the battery light may something to do with it.

 

Thanks again for the pics and directions. Everything worked great, Other then the fact that I am old so it took me the better part of 3 hours haha.

I was able to remove the alternator without draining the coolant. So that was a plus.

 

The fan should be full power
Is it still saying convenience features etc or just red battery?

 

Just red battery. The AC fan is not full power. I crank it up but it just I am thinking the batteries need more charge. Because after I got them both charged. I had to drive to my buddies shop on battery power. It was 11.5 volts driving there. I think I am going to give it another day of driving, THen I will recharge the batteries once again.

13.9 volts today and everything else works, car rips.

 

The AC fan blows full power for a few seconds then it drops down to low power after red battery light. How do I get ride of that red battery light? No messages. DO you know what that means?

 

Weird
It's almost as if convieneice features are off
Does radio work?

 

Yes radio works. I think a fresh charge on the aux battery should do it. I killed the fresh charge by driving with it straight batt power.

 

Maybe you have a drain on the system somewhere that killed your first alternator. How are your fuel pumps? 13.9 seems a couple points low. I remember seeing 14.something.

 

there is something still not "right" with the electrical system?? it could be the battery needing to be fully charged and/or a new battery in order. as the above post stated, you may have a parasitic draw on the battery, the seat module still "awake" while car is off, the audio gateway control module not going to "sleep" etc etc.... so you have some work to do to figure this thing out..... ??? you can start with a load test on your rear battery now and see if it passes that test. if the battery passes load test, then charge the battery up fully and leave overnight and the volts in the morning should be around 12.5 and higher... anything lower than 12.5 on a fully charged battery the night before may (i say "may") signal a parasitic draw. finding those "draws" are a pita!!!! start with seat modules (both) and the agw are known culprits. youtube how to find parasitic draws, you will need a voltmeter. good luck man! btw: your ac will not go to "MAX COOL" until the system recognizes that the battery is fully charged. you still have "convenience functions disabled" right now due to possibly weak battery.

 

red battery warning will get rid of itself once the battery control module/ ecu recognizes that the battery is a fully functioning/charged battery. you got 1 thing fixed by replacing the alternator. if you drove long enough whereby the alternator charges the battery, then that message will go out on its own. so the electrical system is still sensing a "weak battery" and thats why its trying to conserve all its remaining battery power for the essentials. and the reason why your ac is not "working" properly.

 

Yup
Mr. Green is right
Do a full charge of both batteries and then reinstall and check voltage prior to starting.

Also to starvingartist when motor is on voltage can go from 13.5-14.2 depending on what functions you are using.

If you are at idle and put on rear defroster, ac fan full blast and seat heaters voltage might even goto 12.9

 

Right makes sense. Both batteries load tested and checked out fine after the charge. But, keep in mind I drove on straight battery to my buddies shop as I've said a few times.. I believe that drained some battery life. So, now the alternator is doing its best to charge up. But, I think the AUX battery doesn't get full use of the alternator it gets a little help but not like the rear battery. Someone correct me if I'm wrong.

The voltage on multimeter at initial start up was showing about the same volts on gauge cluster for front and rear battery. 13.8 volts. After 1 day I'm seeing 13.9 volts.

OK both batteries will get another charge. IS that ok to do? Even though I Just did it before driving on it?

 

The front battery only gets charged when the relay opens up for it, only when needed. For your ac fan to not work at full force is weird so something electrical is to right, maybe some voltage some where, if you can eliminate all codes via star and see if it clears it up

 

Ill charge up the aux battery, maybe the rear too after a load test. I'll report back to it can help some others who may have same issue.

I don't have star. So thats gotta wait till I go back to complete service on my car. Hopefully next week. Thanks for the help!

Battery voltage is 13.9-14 volts today. Its going up as I keep driving it. The car rips, so that's good.