95 No Start Issue

[mangus580]

Ok... my 1995 Suburban decided to give me a strange issue today.

I have been having problems with the backup lights blowing the fuse. I havent had time to track down the issue, so I tossed a circuit breaker in its place, so at least the signals would stay working once it reset.

This morning, my wife hops in to leave, puts it in reverse, and the engine quits.

Now there are no gauges, and it wont run. Cranks over fine. Radio works, key buzzer works, etc.

I havent tested yet, but I am assuming the turn signals do not.

What i am thinking, is there is a blown 'master' fuse someplace, or a bad fusible link. I am not sure what one though, and I am hoping for some direction.

Looking at a schematic provided by Autozone, it appears the ECM Ign, Turn Signals, and Gauges may be supplied by the same source? (see attached) This would go along with what I am seeing. Sadly the schematic doesnt really show what supplies the 3 in the fusebox.

Please help!!

Mike

 

[mangus580]

Updated info:

I used a test light to confirm which circuits are non-functional:

Fuse # - Name
4 - Gauges
10 - Air Bag
14 - Illum
16 - Turn B/U


Intersting to point out, that schematic shows a 10a fuse for ECM (as does the owners manual) but the tag on the fuse door does not.

 

[mangus580]

Missing schematic

 

[mangus580]

So.... for future reference - its fixed....

I traced it out to be the ignition switch. Went and got a new one, and half way through installing it, I discovered that on the main pink wire coming from the switch, someone had put a side tap in. Presumably for a remote start at some point in its life? Anyway, that side tap had completely cut through the wire!!

I have had this thing for 6 years, and have put well over 50k miles on it. That is something that happened long before i got it!

Must be when the wife put it in reverse, it was just enough a jolt (vibration) in the column to break it the rest of the way apart this morning.

Insert 1 butt splice - and it works like a champ now!

this site - http://www.pswired.com/misc/pacaudio/syswire.pdf - was a huge help in identifying the path of the circuits to and from the ignition switch, and is what really narrowed it down for me.

 

[Will L.]

Glad you got it figured out. My head was spinning on reverse light tie in. I was going to send you down a road chasing grounds, but didnt want to spit out a wild guess. Shooting from the hip is just about the worst way to find it, so I said nothing. Going to guess I wasnt the only one not wanting to lead you astray.

 

[deejaaa]

just saw the thread but was thinking the same thing.
funny how something from so far back can come back to haunt you later in life.

 

[mangus580]

Honestly, I think the reverse light issue is what finally did it in. I am guessing gradually strand by strand broke... getting down to the last couple, which the overload from the reverse light problem finally burned it the rest of the way off.

I still need to figure out where my short is... really frustrating. Need to check the trailer plug and wiring. Wondering if its in there.

 

[Will L.]

Some tools are just cool to hang on a wall like decoration and dont really help at all.

Others help a little, but you can go without it.

This kit will help SOOO MUCH!
https://www.amazon.com/dp/B003QHDLEQ/?tag=jhdiesel-20

Once you work with it a few times, you will not remember how you ever did any electric troubleshooting without it.