Rough start, battery good, glow plugs good - Page 2 - PeachParts Mercedes-Benz Forum

vwnate1 · #16 02-21-2010, 11:05 PM

Should be on the label somewhere , it's 49 .

To service the starter requires removal and disassembly , thorough cleaning before greasing .

As your ground cable is iffy , let me give you a good tip most folks ignore : the starter draws a lot of current and it's attached to the body , not the engine like it should be ~ off the shelf cables are not going to cut it ~ you need to order up a # 1 gauge (I use # 0 gauge) cable .

I made up a custom negative cable that has two mounting leads to it , one goes to the engine (intake manifold) and the other goes to the usual body bolt that I polished and greased for better conductivity , what a difference this makes in cranking speed and cold weather starting ~ I grew up in Rural New England with 6 volt junk so I learned early on the simple , easy way to ensure January starting .

I use welding cable as it has finer strands - as the more strands in any cable , the more current it will carry . most welding shops will make you custom battery cables cheaper than the correct Mercedes ones cost .

This easy ground cable mod. also allows brighter headlights and faster battery charging from the weeny 55a alternator .

900 series SAABS use a better alternator that's a bolt up fittment .

Or , buy a rebuilt AL129X BOSCH brand one .

Or , simply use the original BOSCH voltage regulator / brush holder from an 1989 W-126 , the P/N is : 1 197 311 023 and just fitting this to your crappo 55a alternator , will instantly increase the charging voltage to 13 + VDC except @ idle , you'll love the brighter lights and so on , it goes in in 5 minuetes , no need to dismount the alternator , not even on turbo models .

I hope this helps .

DrewGerhan · #17 02-21-2010, 11:34 PM

i bought a brand new 120 amp alternator from autozone. had to shell out about $150, but its the last one ill buy. lifetime warranty!

Codifex Maximus · #18 02-22-2010, 10:19 AM

Quote:

Originally Posted by Mattbob

woo---eee well that solved it. New battery, cranked like she should. I did notice on putting the new one in that about 8 of the wires that make up the negative cable are split. I'll be getting a new one of those too. Would that have an effect on it as well?

I live in Chicago, and am renting a garage for $60 so it would stay warm enough. It worked, but I didn't think about using that money to wire a second battery instead.

Now this is a man who cares for his car! Not enough places here in Texas to hide from the sun in the summer.

Mattbob · #19 02-23-2010, 10:11 PM

Awesome awesome. I didn't know the gauge of the ground cable would have an effect on the cranking. I saw a replacement cable with two leads (2 gauge) and I was wondering how that would work. How is the 2nd lead attached to the intake?

For the custom connection I need one two lead 0 gauge terminal, o guage cable (approx3 ft?) 3 ft insulation, a connection to ground on the body and some type of connection to ground on the intake?

Yeah I thought I would give the car some garage love this winter. It has treated me well. Well enough to want to give her a shiny new black paint job in spring... although its yellow now so it wouldn't ahve to treat me -that- well.

vwnate1 · #20 02-23-2010, 10:33 PM

Yes , as the starter draws up to 800 amperes , it needs all the help it can get and attaching the ground cable to the body was a serious engineering gaffe .

As far as to where to attach it to the engine , remove the aircleaner can and look for an 8 MM bolt , do not use the exhaust manifold .

I'd imagine a # 1 gauge cable would work , the main thing is to have the ends soldered on ~ any one , in any vehicle who has one of those
' repair ' add on battery clamps , is setting themself up for starting and other electrical problems .

In time I need to make up a similar positive cable that has a 2 MM lead going directly to the alternator , this will improve charging quite a bit too .

I had a JPEG of the negative cable I made , if you keep after me I'll hunt it up and post it here .

vwnate1 · #21 02-23-2010, 10:47 PM

Be careful about doing a color change ~ they rarely look good unless the entire vehicle is taken apart as the door jambs and trunk , underhood area etc. will all look nasty with a different color .

Some of the various yellows Mercedes used are very pretty once they're polished up .

Mattbob · #22 02-23-2010, 11:36 PM

I work at Mcmaster Carr so I was hunting around teh catalog.

http://www.mcmaster.com/#69735k43/=5y91b5

part # 69735K43

I'm 'assuming' 1 AWG is the size we are talking about. I was thinking go that cable to the air cleaner bolt, then a lug to lug to the body. I'm probably going to put another battery in anyways, so the extra long cable wouldn't hurt.

vwnate1 · #23 02-24-2010, 12:00 AM

My , aren't you the lucky one !

Remember : I was talking about using Welding cable as 1 AWG is rated for more current than 1 AWG battery cable is .

If you solder it up , you can end both cables into the negative clamp .

Then yes , one cable goes to the original ground connection (with a new, greased bolt and star washer of course) and the other one goes to the engine.

Mattbob · #24 02-24-2010, 12:21 AM

Not having the car in front of me... would it be a good idea to do the same thing for the postive cable?

7940A26 1/0 welding cable 10 ft length if anyone was wondering.

We surprisingly don't have a terminal connector with dual leads. Maybe a suggestion to the boss.

vwnate1 · #25 02-24-2010, 08:34 AM

yes indded ! .

Both the reduction in current loss and the application of a proper drivetrain ground will vastly improve starting (cranking speed) cold or hot , especially in cold weather country .

The bean counters always force the use of marginal battery cables .

Back in the days of 6 volts , only VW's with thier tiny low compression engines , used 4 ga. cables and the ground strap was always connected directly to the drivetrain , not the frame nor body .

Adding a drivetrain to body grounding cable brightens up the lights of most any older vehicle .