Starter not grounded properly? - Page 2 - PeachParts Mercedes-Benz Forum

ah-kay · #16 01-29-2013, 05:46 PM

Quote:

Originally Posted by Stugist

Apparently, the starters can ship with residual charge in them.

I really do not want to confuse you with any more info than what is posted here already. Most of the info here is wrong or mis-leading. You need to sort out the wiring, starter circuit is extremely simple. I do not have the same car so I cannot tell you the exact configuration but it is similar in ALL old cars.

There is NO residual charge in a starter. Anyone tell you that is BS. There is no CAPACITOR in a starter. Even if there is, it is so small that it would have discharged very quickly thru the winding. Recheck your wiring. what have been posted does not make sense. No need to remove it, just check the wiring for now.

whunter · #17 01-29-2013, 06:44 PM

Quote:

Originally Posted by Stugist

The car in question: my girlfriend's '79 240D automatic.

It's been having issues starting since we've gotten it. I determined it was a number of issues, including air getting into the fuel system via a bad IP seal to injector hardline #4 (still have to fix that) and a starter/solenoid combo going bad. It's the latter that's giving me real issues.

I got a rebuilt Bosch turbo starter from -insertobvoiscompanyhereinBellinghamWA- and spent a good 5, 6 hours finagling the old one out and getting this bad boy in. Near the end, I was having difficulty wiring-up the new starter, mostly not remembering which wires go where. Saw this by arching and bad sparking when touching the battery terminals with the connectors, meaning there was obvious load on the system. Called my friend over who also is a dieselhead to help me, and we finally got it hooked up and started with no issue (other than the air leak making the turnover difficult).

It went all south last night. I drove her car to college to stretch its legs. Started up fine at the house. Didn't even engage when I tried to start it after class a few hours later. Turn the key, wait for the glow light, turn to fire the starter... -click-. Hit the starter and solenoid a few times, kept trying. Nothing. Called AAA and they sent out a local tow truck. Told him my issue, so we both started messing with it. Here's what gets me confused: He took out a metal rod and when he touched the positive terminal of the starter and the support bar for the air cleaner housing, it started right up. Now, I now you can normally bypass the switch by jumping the connection between the positive starter terminal and the small terminal for the ignition switch. But he just grounded the system. I thought the starter grounded itself to the block...?

So, tl;dr version: Is the starter not grounded properly?

The bold text tells the story.
If the battery was not getting a boost ?

My diagnosis would in order be:
#1. A bad starter/engine ground connection.
#2. A failing neutral safety switch.
#3. A failing ignition switch.

.

Diesel911 · #18 01-29-2013, 07:55 PM

Quote:

Originally Posted by Stugist

So, just to be clear, the main wire from the battery comes into the top terminal, and the wire to the alternator also connects to that top terminal. There are two small wires; a purple one which I assume is the direct line to the starter, and a bypass line for the glow relay. Nothing connects to the bottom (ground) large terminal.

Right...?

The Nut and Strap that are between the Starter Housing and the Solenoid is another Posative connection. When the Solenoid Moves it connects the large + Termnial with that lower Large Termainl and that is what causes the Starter to rotate.

I don't remember if this is a Pic of a Delco Starter or a Mercedes Starter but they both have similar parts and work the same.
The Red arrow point to the 2 High Amperage Contacts that the Solenoid connects to each other when the Sonlenoid is activated.

Diesel911 · #19 01-29-2013, 07:58 PM

If nothing is happening at all when the Key is turned it could be the Neutral Safety Switch or the Ignigion Switch.

When you Turn the Key to the Start Position one of those Purple (Violet) wires that attaches to the small Terminal on the Starter Solenoid should get Voltage.

layback40 · #20 01-29-2013, 08:02 PM

Quote:

Originally Posted by Diesel911

The Nut and Strap that are between the Starter Housing and the Solenoid is another Posative connection. When the Solenoid Moves it connects the large + Termnial with that lower Large Termainl and that is what causes the Starter to rotate.

I don't remember if this is a Pic of a Delco Starter or a Mercedes Starter but they both have similar parts and work the same.
The Red arrow point to the 2 High Amperage Contacts that the Solenoid connects to each other when the Sonlenoid is activated.

That looks like a w123 starter!

layback40 · #21 01-29-2013, 08:07 PM

Quote:

Originally Posted by Stugist

The car in question: my girlfriend's '79 240D automatic.

It's been having issues starting since we've gotten it. I determined it was a number of issues, including air getting into the fuel system via a bad IP seal to injector hardline #4 (still have to fix that) and a starter/solenoid combo going bad. It's the latter that's giving me real issues.

I got a rebuilt Bosch turbo starter from -insertobvoiscompanyhereinBellinghamWA- and spent a good 5, 6 hours finagling the old one out and getting this bad boy in. Near the end, I was having difficulty wiring-up the new starter, mostly not remembering which wires go where. Saw this by arching and bad sparking when touching the battery terminals with the connectors, meaning there was obvious load on the system. Called my friend over who also is a dieselhead to help me, and we finally got it hooked up and started with no issue (other than the air leak making the turnover difficult).

It went all south last night. I drove her car to college to stretch its legs. Started up fine at the house. Didn't even engage when I tried to start it after class a few hours later. Turn the key, wait for the glow light, turn to fire the starter... -click-. Hit the starter and solenoid a few times, kept trying. Nothing. Called AAA and they sent out a local tow truck. Told him my issue, so we both started messing with it. Here's what gets me confused: He took out a metal rod and when he touched the positive terminal of the starter and the support bar for the air cleaner housing, it started right up. Now, I now you can normally bypass the switch by jumping the connection between the positive starter terminal and the small terminal for the ignition switch. But he just grounded the system. I thought the starter grounded itself to the block...?

So, tl;dr version: Is the starter not grounded properly?

He probably bumped the air cleaner housing unintentionally. What he was doing was shorting across the starter between the 2 main terminals on the solenoid. You have an issue with the solenoid or the control wire.

layback40 · #22 01-29-2013, 08:10 PM

Quote:

Originally Posted by ah-kay

I really do not want to confuse you with any more info than what is posted here already. Most of the info here is wrong or mis-leading. You need to sort out the wiring, starter circuit is extremely simple. I do not have the same car so I cannot tell you the exact configuration but it is similar in ALL old cars.

There is NO residual charge in a starter. Anyone tell you that is BS. There is no CAPACITOR in a starter. Even if there is, it is so small that it would have discharged very quickly thru the winding. Recheck your wiring. what have been posted does not make sense. No need to remove it, just check the wiring for now.

X2
ah, this is absolutely correct.

vstech · #23 01-29-2013, 08:36 PM

so... what does the car do now?
ZERO chance bumping the air cleaner housing had ANYTHING to do with starting the car. however, if he connected the rod from the negative cable on the battery and touched to the air cleaner mount, THAT might have given the starter a solid ground, and allowed the start.
my bet is the shifter bushings are off... what confuses me is the click...
NSS would not have allowed the click. a dead battery will cause the starter to click...
most likely, the starter is internally worn, and needs replacement if it clicks with a good battery, if the battery is good.
a weak ground strap will cause the starter to merely click, and not start.
the pic above of the ground strap is similar to what the 79 would have, but it's shorter.
the cable will be on the driver's side.

Stugist · #24 01-30-2013, 01:41 AM

Just got home. Girlfriend informed me that she drove my brother's fiancee home earlier while I was out. Told me the car started no problem. I'm not doing anything after work tomorrow, so I'll pop the hood and start checking the system over, starting with the battery. I'll post pics, too. From what I've read, I'm mainly looking out for bad grounds. I'm pretty sure it is wired up correctly, but I'll take a pic or two of it. Now here's a question; As I've mentioned, she has the pencil GP upgrade. There's a wire running from the GP relay to the battery AND to the starter, where it connects to the same terminal as the ignition wire. I'm not entirely sure how that system works. Is it to compensate for the fact that the parallel-style GP system needs more juice than the factory relay can produce?

I know it's slightly unrelated, but I want to be sure that it's wired properly.

vstech · #25 01-30-2013, 09:07 AM

if the pencil upgrade included a MB pencil relay, the wire going to the starter is to let the relay know you've started the car so it can shut off.

Diesel911 · #26 01-30-2013, 08:25 PM

Quote:

Originally Posted by vstech

if the pencil upgrade included a MB pencil relay, the wire going to the starter is to let the relay know you've started the car so it can shut off.

The Wire (on mine Violet) connected from the Glow Plug Relay to the Starter Solenoid keeps the Glow Plug on during cranking. Releasing the Key from cranking turns the relay off.

On My Car the Steering Colum Lock is out of the car and the Ignition Switch came with it and I needed to start and move My Car. I used that Prurple (Violet) Wire applied to + Voltage today to preglow and then took the wire that goes to the Solenoid and appled to the + to crank and start.
I just did that about 1 hour ago.

dubadxx · #27 01-30-2013, 10:16 PM

What is happening when the starter whines when you turn the key? usually a couple attempts later it will turn over and the starter will engage and start the car.

whunter · #28 01-30-2013, 10:53 PM

Quote:

Originally Posted by dubadxx

What is happening when the starter whines when you turn the key? usually a couple attempts later it will turn over and the starter will engage and start the car.

* The starter solenoid is (damaged) failing to engage.
* The solenoid lever "pivot pin" has (loosened) backed out.
* The starter solenoid mounting screws have (loosened) backed out.

Remove the starter for inspection, and testing.

.

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