W124 500E won't even crank
 

Our 1993 W124 500E won't even crank-over.

When I turn the ignition switch, everything has power, lights works, gauges
work, fuel-pumps start whirring, but nothing at the starter.

No sound of a solenoid clicking. Battery fully-charged, lights don't even dim
when attempting to crank. I measure 13.3 VDC at the B+ distribution block. I moved the tranny lever to Neutral and up & down to see if its is the neutral safety switch, but I'm not sure how to "jumper"/bypass this switch.

What's the test procedure and points/areas to check for voltage to the starter ?

I found a 3-pole connector near the CAN/LH electronics, which supposedly goes between the ignition switch and starter solenoid, but I don't know how or what leads to test for voltage.

The factory CD-ROM is poor here.

BTW: 3-months ago, I replaced the ignition tumbler, switch, and locking assembly with NEW MB OE parts.

TIA,
:-( neil

The 1993 -95 cars have a starter lock-out relay(anti-theft).

The alarm module sends ground signal to that relay(K38).
The relay gets power from fuse "B".

Yes, I tested that starter-lockout relay behind the instrument cluster, and it's working.

Since I can't get a test lead onto the starter, I believe there is a connector that I can "tap" into and test, that is between the solenoid/starter and the harness.

Is this the connector with 3-poles and is under the ABS wheel-sensor connector that is located on the back of the LH/ABS/ASR electronics box (passenger side in USA) ?

If so, I see three wires, Violet/White, and Brown/Black, and Brown/can't remember.

How/which ones do I test and what am I looking for ?

TIA,

:-) neil

http://www.peachparts.com/shopforum/tech-help/119245-94-e320-wont-start-weird-problem.html

From the thread above. On the 500e the starter motor test will be a bit more difficult since the battery is in the trunk. There is a 3 prong connector near the brake booster/reservoir...

I have verified that the 3-prong connector on the 500E is NOT located near the brake booster, but mounted on the back of the LH/CAN electronics box, and under the ABS wheel sensor.

Otherwise, that link provides me the diagnostics needed.

Thanks,
:-) neil

That cut/paste diagnostics test was written by me and it was a posting for a 124.032 , E320 chassis specific.
Be very careful when jumping 12V battery power on any electronics as you can very easily cost yourself some shorted expensive parts.
When I post a test procedure for a specific model, I would prefer people don't cut/paste that info for diagnostics on a different model, as the assumption they are the same is a cause for concern.

As you have the CD , go to starter circuit schematic and you will see the starter lock-out series chain..
If you do not find it , I will look it up for your specific chassis.

Is it in the ETM section ?

Thanks,
:-) neil

PS: I'm in JAX, FL, how about you ?

Ocala area .. down from New England

Yes , ETM, then go to wire diagrams, then starter/battery /119/LH

Don't use 104 ..it is different.
The schematic # for your chassis is 15-2.00

Go to K38 relay section and you will see the series chain , from Ign sw thru the ATA and NSS circuits .. any open in this series will result in a No starter feed.
Also note the Canada section that has a jumper for K38 relay.. that is b/c they do not use that system [ that is also how you can jumper the K38 for TA testing]

Let me know ...

:huh:

Sorry for posting the wrong information. I exemplified the "definition" of ass-u-me.

Thanks Arthur for setting the record straight.

Thought I put this all together for posterity sake:

Symptom:

Engine will NOT turn-over. That is, the starter will not operate.

Here's a basic description:

Ignition Switch (S2/1) via PIN 50 (VI) connects to Starter Lock-out Relay Module.

Starter Lock-out Relay Module (K38) on is connected to S2/1 on pin #1 of Relay.
K38 is located behind instrument cluster.
Short pin#1 and pin#3 to by-pass K38.

Neutral Safety Switch (S16/3) is connected to K38/pin#3 via connector X49/2 on pin#7.
S16/3 is located on the transmission.
Short pin#7 (VI) and pin#8 (VI/WHT) to bypass S16/3.

Starter Solenoid (M1) is connected to S16/3 via connector X27, on pin#1 (VI/WHT).


In short:

Ignition Switch --> Starter Lock-out --> Neutral Safety Switch (NSS) --> Starter Solenoid

After verifying all fuses esp. Fuse B and Fuse C (which control relay K38), strong battery & ground, and 12VDC at Alternator B+ distribution block (behind LH box), it is easier to start diagnosis at the END of the chain (e.g., starter solenoid).

Disconnect connector X27, and while in PARK or Neutral, jumper the CENTER pin (male, pin#1. VI/WHT) to the B+ distribution block.

The solenoid should audibly engage and the starter should turn-over the car.

That is, if the engine turns over, then you work your way backwards measuring voltage (or using a diagnostic light) and jumpering to find the faulty part, wiring harness, and/or connector.

You can also hookup a voltmeter or test-light to the center female connector X27 to verify that turning the ignition switch is also providing 12VDC.

:-) neil

PS: in my scenario, the solenoid is receiving power, but not engaging, so I'm going to replace the starter/solenoid assembly and the harness while I'm in there.

N,
Very good .. you would make a good diagnostic tech , vs a parts changer.
You can easily now see why I recommend starting at the 12v feed spot in the circuit... this is the perfect mid-point for diagnosis as it is where the switching controls and the actual starter circuit meet.. it is also where the cabin and engine compartment wiring seperate..
Backwards is always the simple route.. for guys who don't understand electric circuits , I often tell them to think 'Plumbing". where the wires are just pipes, with shut off valves and water feeds .. makes the basic concept look much less confusing..
... If there is one good thing about the CDs, [ probably the only one] . it is the schematics...with those, a test lamp and a jumper wire , you can trace most simple series circuits/systems out pretty well... another trick is to print the schematic out and use a High-Liner pen for tracing that particular circuit,,don't get your wires crossed that way, as there are a ton of them...

Thanks for the kind words. I guess putting together those HeathKits and dabbling in ham radio pays off. . .

BTW, while I did the diagnostics, changing out a M119 starter without a lift is a PITA. I'll have my tech do it next week!

:-) neil

Yeah... "Experience keeps a Dear School that fools will learn in no other " B.Franklin..
Guess we went down the same road .. I got my Ham Ticket when I was 14
[ KN1DMS] and built both Heathkit Rx/Tx .. An AR-3 and an AT-1 ... big rig, Huh??? .. ).. WAS with it , though..
I see them now on Ebay as Classics and they bring twice what I paid for them way back then [ Early/Mid 50's]
_._. _ _._ _,_

You have my sympathy, but if you can't get it running,,, I'll take it.

Replaced starter in about 2.5-hrs, and all is well.

Tips here:

http://www.peachparts.com/shopforum/tech-help/136260-w124-m119-400e-500e-starter-replacement-tips.html

:-) neil