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So what's the problem ..that is Exactly my point. Go re-read the post, or better yet , do a search on "X27 "
The test point takes any component out of the fault equation DOWNSTREAM from the X27 test point..so, if the starter cranks when we jump 12 v power to the x27 test point, we then know all is well from that point On..that includes starter, solinoid , cables ,starter ground, etc...and we now know the problem is UPSTREAM from the test point...just like I said ..K38 relay, ign sw. and NSS switch are then suspect, as that is the series circuit feed chain for starter soinoid circuit on that chassis.
The resaon we use that x27 connector is b/c it is the midpoint between the cabin feed [ ign sw/nss/and starter lock-out relay,K38] and the actual starter/soinoid circuit.
The point being, we are not concerned with a high amp jumpering when we jumper 12v to this test connection...it is simply a jumper of the cabin ignition sw and NSS/K38 lockout...very effectve and convienient test for a diyer , without being told to watch out for the high amp arching that a jumper to a starter would entail.
Ask around here how many have used the x27 connector test I post in order to remedy their No crank condition....... it is the first test one does for this condition and it is not a Dangerous Test..that is where I disagreed with the posters Warnings.
A Dalton
BenzTechs

Ah, you are correct, after re-reading I see what you are saying.. I stand corrected on questioning your post. Just so you know solenoid isn't spelled solinoid. Hope I got that right.. grin.

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Bill

Backyard Shadetree Mechanic, 30 years running.

1987 300TD
1988 300E (sold, sniff)
1999 S320
1981 Volkswagen Rabbit Truck (Diesel)
2001 Ford Expedition
1988 Suzuki Samurai
On my list to buy: R129, for me, and a R107 for my wife.

No problem..you probably missed some of my post cuz you were too busy rolling your eyes about...

..anyway , I can see that you have the test procedure down too...

My function here is to do diagnostics using a sequenced format of test steps for the diyer , and in doing so, it is difficult to get the results from such a varied audience. My preference is those who know what a DMM is and can give me back some readings so we can go to the next test step. I usually have their schematic up on another screen to aid us in the logic chain, but there are some who just are better off driving it down to their local guy b/c these electrical problems can be frustrating to those who do not have a general electrical background, and even worse to those who have a fear of electricity ...
As you know , our meters and scopes and HHT scanners , etc. make the job easy, but I also know that in many cases I can guide an owner with basic skills and no testing tools through his problem/condition with the aid of a 12v test lamp and a couple of jumper wires...so that is why I go for the x27 quicky test in my diyer first test step.. this is the most important test to get them in the right direction. [ et al .....this is also a good piece of info in the event that one gets stranded with a no crank condition from a bad Ign. sw or NSS ...saves the Tow Truck fee]
We have gotten many a diyer back on the road with very minimal $$$ spent by having them do a few simple jumper, test lamp verifications at certain test points in the system by simply giving them the test points that we would take ourselves if we where on location..
....and that is what the Forum is all about.

I agree, good troubleshooting skills and methodology are a must.

__________________
Bill

Backyard Shadetree Mechanic, 30 years running.

1987 300TD
1988 300E (sold, sniff)
1999 S320
1981 Volkswagen Rabbit Truck (Diesel)
2001 Ford Expedition
1988 Suzuki Samurai
On my list to buy: R129, for me, and a R107 for my wife.

Yeah....and when we have no meters/tools , we resort to using the
" Macgyver Methodology " ........

I told you why in my original post. It sounded like you were talking about jumping power to the starter. Obviously, I'm not a technician, but since you don't know, I am a competent diy'er. No need to be defensive about it. Just a little more explanation, and I'm on board. I do know the difference between the solenoid amp draw and the starter motor amp draw. Really.

I believe it's not a good idea to give too little information in posts particularly for the benefit of inexperienced practitioners who for the most part don't know what they are doing. With your further explanation, it is now quite clear exactly what the test is accomplishing and what it is not accomplishing and also that there is no high current danger. I appreciate you making that clear.

Any insight on a fast idle on an M120 after removing and cleaning the throttle bodies? Where would you start?

Brett

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1997 S600 sedan