Howdy,
Last night a good friend of mine towed his '95 Blazer to me asking for help. In general, around January, he was driving the car when engine shut down. Since that time, he left his car to some local guy who ... made things even worse. To give You a better picture - imagine a varmint on amphetamine under Your hood closed for a week or two. As for example - today I've taken out the battery for charging - 3.3V, already expanded. Normally I'd send a person right away, but I am going to take my chances.

Kindly asking of a wiring diagrams, especially an ignition section. '95 has a different wiring arrangements and accessories than my '00. I have to distinguish a standard wiring from LPG installation and that "varmint activity", manifesting itself by some disconnected, damaged relays thrown over the engine block, and a trunk full of parts from engine bay (guy made me a **** lego bricks).

P.S. What is the exact engine type here? It has an aluminum casted plenum on top, not the plastic one. I'll try my chances to find a service manual.

Cheers,
Mike

 

Mike have you ever seen the factory service info on AlldataDIY.com. It's subscription based factory info, including wiring diagrams.

I would never tell anyone to download the GM Techline eSi DVD that covers 1996-2005 from the Internet or buy it from ebay. That would be copyright infringement.

 

Ok, I swapped a battery and tried to crank. A dashboard indicators dimmed a bit but nothing else. I guess I gotta check the power lines to a starter and the control logic. For now, I put that on a poor conductivity of a starter power wires.
Meanwhile, I found a damaged positive wire, at the battery shelf with a plug (3 pins wide, one in use). What is that circuit? That may lead me to the source of a problem.


Next, I have found several strange boxes altering the installation. That one concerns me most. I haven't dig much into the FOB devices yet. It seems to be a proxy for some ECU signals:

 

Matrix must have put me on some hard questing tasks
So far, I cannot make the starter crank on a borrowed battery Tapped on to the starter power pins:

• 12V on idle
• 10V on ignition

..still no movement. Time to lift the engine block to take out the starter. Meanwhile I gave a call to my friend asking if he recently had a problem with starter. Confirmed. My friend said it was replaced around December for a replacement one. They seem to last for 3-4 months, and if You wonder why, here's the picture:

That worn off pin was meant to deliver the pos. battery power line to the starter motor. The negative one is passed via engine block. Now here is my question - what kind of seal should be used in between the mount and a starter? A varmint-on-drugs left a thick piece of rubber (that unfortunately does not pass the current, but probably passes the water way better).


I wonder if there should be some conductive seal or RTV and the bolts are good enough?

 

Revealing the mystery. That box is hooked to ECM:

• GND
• IGNITION FEED
• VSS

A dashboard has speedometer in km/h, so I assume this could be some sort of a signal converter (in sense of a pulse multiplier to convert miles/h to kms/h) to . Looks crappy and as far as I remember, my friend was complaining, that his speedo was all dead.

 

IMHO The starter has no gasket. Eventually a shim but should be conductive because routing the immense currents that go with cranking. No wonder the thingy has marks as from welding.

It looks odd thou. Should be a washer type connector for the cables...

Which type of dash do you have?

 

Sorry for a bit late update, yesterday my own chevy got grounded so I had to reschedule jobs. My house is surrounded with a dead blazers atm

Thanks for clarifying starter gasket issue.

Today I got a parcel from a friend with a genuine starter that was initially busted, so tomorrow I'll drop it together with a chineese one in a local workshop crossing my fingers they will bring one of them back into operation. As a relaxing job of today's evening I took the ignition coil and ICM out of the car (to remind You - the car was delivered as intermittent cranking, no starting).

The ignition coil has a connector for 2 plugs/2 wires each. Tried to create a spark by supplying a several tiny 12V pulses to a primary winding, but failed. I also have another, good coil, but with a 1 plug/3 wires - so I can compare two different coils for same engine :P A comparison looks as follow:

Suspected one Good one
primary [Ohms] 0.6 0.4
second. [kOhms] 7.2 8.2
primary [mH] 0.95 2.6
secondary [H] 6.7 32.8

Transformer ratio for a good working one is around 15600, while for a suspected one 7052. Cannot clearly say whether the suspected coil is OK or not :S There is a trick to check the transformer windings for short circuit, but I have no vital forces today to work on a sine wave generator