Ok, I pulled those from the most common VCM-A setup, but you have the PCM setup. 95 was truely a VERY screwed up year!

I'll grab the other ones tonight. Hopefully I can do it the same way I grabbed those with minimal rework, LOL. I got those from an AllData service DVD I have access to.

 

ummm I'm hoping you have vcm-a and pcm confused.. because all of the wiring diagrams that most fit my vehicle have been from vcm-a.... color codes and pin locations on vcm-a harnesses

heres a post I found on obdii.com





#14106 - 01/22/02 09:02 PM Re: 1995 Blazer

Finz Finz
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Registered: 01/21/02
Posts: 3






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Thanks for all the inputs. I received an E-mail of how to tell the difference between VCM and VCM-A. For those who are interested; VCM has (3) larger cable assemblies side by side, and a forth (assumed pwr cable) also in horizontal line. The VCM-A has (4) larger cable assemblies double stacked 2 & 2, one over each other, with what I'd call the pwr cable centered on top row, (5) total. The VCM-A also shows ribbed heat sink fins vs flat for the VCM. VCM-A has connections on Pins 2,4,16 on the schematic, while VCM shows pins 4,5,6,9 as being populated. Since VCM has no pin 2 connection this would not have a chance of working on an OBDII scanner. Only the VCM-A has a chance. Since I know someone else who has a 95 Blazer also can't read out codes with the Actron scanner, I'm not suspecting a computer problem just yet. At least at this point I can tell the scanner sales folks I've got a VCM-A. I'm getting closer!

 

yeah, sorry, my mistake. Going from memory and typing fast while at work.

 

ok kool.. and I found two issues.. one is the oil pressure sensor terminal C has 0Volts key on or off.... though terminal GR21 has 12 volts and fuel pump relay terminal 5 has 12 volts all orange wire from fuse #9 ..just as sooncut it and patch in a new feed from a clean spot by the vcm pin GR12...and the second issue I have is a little odd (like this whole darn thing isnt) well the ignition coil control/driver module terminal C had 7.5-9.0 ohms, 0.006 voltswith the key in the run position...even with a new ground paralleled to it... same results...with the key off.. it has 0.0 ohms...0.000 volts.... so where do I go from here??? it says on the schematic this is a ground... can I jsut cut this and abandon the black wire(wherever its shorted to ) andinstall a clean ground of my own???? these would both explian the stalling while running.. ops... and the no spark.. icm... no ground... or weak ground signal.... sound like a plan???.. otherwise I think I'm looking at ripping out a good chunk of the wiring harness and laying it on the ground.. and wire by wire going thru the damn thing... looking for nicks or abrasions or sharply bent wires that could have possibly broken in the insulation... so OTHER THAN THAT.. how do the other ideas sound????

 

I'm afraid that without being there, seeing what you are going through, it is very difficult for me to offer up an opinion of what is the proper way of going through this stuff. Wiring problems are one of the MOST challenging problems that anyone can come up against in a modern vehicle. I am not fully sure that I could even research the problem enough with the references I have access to inorder to be able to help you more with the limitations that are present (over the internet vs. in person).

Attached below you will find the connector views for the VCM-A setup:

 

awesome thanx for the info.. and yeah I'm assuming as much wihtout being present its hard to diagnose.. and like I said before << licensed electrician... the small question I have I didnt SEE any splices for the ignition coil ground.. so that should be a clean singular ground coorect.. and if so... I can snip and patch on my own... but I have a gut feeling theres something pretty mangledin the harness.. cuz none of this answers the prime relay issue....
does this at least SOUND logical?? provided my back feels better tomorrow I'm going to implement these things and give it a ****in whirl.. the thing I'm not sure of is why when the key is on I get a resistance to ground on the coil connector.... very odd.... but alas I will post my findings.. maybe this was a morecommon issue with the 95s... since I've found at LEAST 4 with the same issue... but none of them posted results... this doesnt take into account how manyjsut burned the trucks for being such a pita...lol

 

This might help:

 

yeah I have that thats the diagram I'm refering to with terminal C of the icm... but would it be safe to say????.. key on or off that shouldn't affect resistance????... that should jsut be a solid clean ground????
....( the resistance indicates to me that wire is shorted in the harness somewhere to another wire... or few)

 

Yes, that would be a proper assessment. I would be worried that it might be shorting with some other wires in the harness... Maybe find where that ground is in particular and what wire at that ground location is the one that runs to the ICM and cut it there as well as at the ICM. If it is shorting out inside the harness, you really should find out where...

 

yeah I'm gunna work on that tomorrow provided I can move I dunno what I did today but I did somethign to my back.. drugs, alcohol and a heating pad later... I'm still in a lil bit of pain.. so this may be waiting a bit longer... but Ithelps to be able to bounce ideas off others.. and it helps knowing I have a lead and a direction to head on.... thanx for the help.. I'll be posting every step...:-P