87 300 SDL Warning lights - PeachParts Mercedes-Benz Forum

ncmark · #1 01-09-2008, 06:05 PM

The battery light stays lit along with the low fuel light. Brake light is dim red and everything up to including low washer fluid are amber. Went to go home today and had to get a jump. Since I have been home, I have gone out and tried to start it and it started ith no problem. Also the fuel guage and speedometer work when they want to. Any ideas on whats going on?

daw_two · #2 01-09-2008, 07:42 PM

May I suggest you charge the battery up and then have it load tested.

bustedbenz · #3 01-09-2008, 08:21 PM

When mine did something kind of like that, the alternator was shot.

ncmark · #4 01-09-2008, 09:44 PM

Quote:

Originally Posted by daw_two

May I suggest you charge the battery up and then have it load tested.

The battery is only 4/5 months old.

Hatterasguy · #5 01-09-2008, 10:27 PM

Its probably the alternator not charging.

ncmark · #6 01-13-2008, 08:38 AM

I charged the battery and now the damn car wants to idle rough. What the hell is going on now?

Hatterasguy · #7 01-13-2008, 10:05 AM

Whats the output on the alternator?

markg612 · #8 01-13-2008, 10:32 AM

Quote:

Originally Posted by ncmark

The battery light stays lit along with the low fuel light. Brake light is dim red and everything up to including low washer fluid are amber. Went to go home today and had to get a jump. Since I have been home, I have gone out and tried to start it and it started ith no problem. Also the fuel guage and speedometer work when they want to. Any ideas on whats going on?

Buy one of these put it in, be happy. The brushes and regulator are together as one unit and two small screws hold it in place on the back of the alternator.

Order it on line, $29 bucks, be there by Wednesday, takes 2 minutes and a screw driver to install.

http://www.importeccatalog.com/

PN# F401039368 its a BOSCH oem part.

ncmark · #9 01-13-2008, 04:16 PM

will this help the rough idle?

markg612 · #10 01-13-2008, 04:28 PM

Ya know, if the rectifier diodes in the alternator are breached, i.e., they're failed closed, you'll get all sorts of weird stuff--If you can disconnect the output lead from the alternator and pull the regulator connector off, charge the battery and all works fine, the diodes are shot and not the voltage regulator. (new alternator) Reattach the output line and if nothing changes, then new regulator.

The electrical side of the car likes 14.2 volts, strange behavior would result from an under-voltage or reverse polarity situation with a bad rectifier diode far as the ruff idle, there is the electric idle module on the back of the injection pump. The mechanical idle stop is below the electronic idle in any case and your engine might not like a 450 rpm's, hence the rough idle. I'd surely attack the charging system issue first and then the other system malfunctions second, considering they may all be resultant from the your system voltage below the desired 14.2 VDC

ncmark · #11 01-13-2008, 09:14 PM

Quote:

Originally Posted by markg612

Ya know, if the rectifier diodes in the alternator are breached, i.e., they're failed closed, you'll get all sorts of weird stuff--If you can disconnect the output lead from the alternator and pull the regulator connector off, charge the battery and all works fine, the diodes are shot and not the voltage regulator. (new alternator) Reattach the output line and if nothing changes, then new regulator.

The electrical side of the car likes 14.2 volts, strange behavior would result from an under-voltage or reverse polarity situation with a bad rectifier diode far as the ruff idle, there is the electric idle module on the back of the injection pump. The mechanical idle stop is below the electronic idle in any case and your engine might not like a 450 rpm's, hence the rough idle. I'd surely attack the charging system issue first and then the other system malfunctions second, considering they may all be resultant from the your system voltage below the desired 14.2 VDC

Not very mechanically inclined, so I dont understand what you said here.

Hatterasguy · #12 01-13-2008, 09:17 PM

Your engine's idle is controlled by the SLS system, which will act funny if you remove the battery, or if the charging system is messed up. A rough or in general crummy idle would result.

I still think your alternator is dieing.

ncmark · #13 01-14-2008, 11:12 AM

Quote:

Originally Posted by Hatterasguy

Your engine's idle is controlled by the SLS system, which will act funny if you remove the battery, or if the charging system is messed up. A rough or in general crummy idle would result.

I still think your alternator is dieing.

So should I just replace the alternator or VR? Autozone has the BOSCH ALT. $200 plus core.

markg612 · #14 01-14-2008, 12:05 PM

Carquest is now owns worldpac, they are very competitive with every vender but importec

I'd still give the VR a shot, at $26 bucks, you'll have a spare.

PART NUMBER SEARCH RESULTS WITH PRICES

Vehicle 1986 Mercedes Benz 300SDL
Part: Alternator

Note: AL 65 X : 70 Amp.
Some early versions now use this later model alternator. Installation of old pulley on new unit may require the removal of spacer on front shaft. No woodruff key is used. A 22mm wrench and a 8mm Allen wrench is used to torque nut to 70 + or - 5 Nm.

Product Brand Availability Retail Our Price

F4000-10137 Alternator 70amp - Remanufactured Bosch IN STOCK $182.05

Vehicle 1986 Mercedes Benz 300SDL
Part: Voltage Regulator

Product Brand Availability Retail Our Price

F4010-39368 Voltage Regulator Bosch IN STOCK $29.40

F4010-108169 Voltage Regulator Germany IN STOCK $26.38

Hatterasguy · #15 01-14-2008, 12:32 PM

Quote:

Originally Posted by ncmark

So should I just replace the alternator or VR? Autozone has the BOSCH ALT. $200 plus core.

When I ordered an Autozone rebuild it had the wrong shaft so the pully would not fit. The shaft was from an M116 which uses V belts. The 603 and M116 share a few parts.

I ended up buying mine from Fastlane. Check the alternator first, see what its charging, or have Autozone bench test it.