1990 Suburban ECM-1 fuse blows, again & again :-(

[MrMarty51]

Don't forget, I'm from So Cali. Guess not redneck enough to understand wonky.

Backwards woodz montananz unnerstands that.

 

[RetroC10Sport]

Don't forget, I'm from So Cali. Guess not redneck enough to understand wonky.

When you come down here, remind me to kick you in the nuts. We'll Rochambeau for squarebody parts.

 

[CWGRL]

So then we just need to figure out what both your Burbs have in common to figure it out that most other squares don't have. How about Power Mirrors?

BINGO! You're right!

 

[Jims86]

The purple wire to the brake switch is also running off of the ecm fuse. It is junctioned into the pnk/blk. check around the brake pedal, and make sure something that moves didnt chafe the wire.

 

[CWGRL]

Ok.... I've been up, over, under every wire... nothing frayed, burnt, exposed, etc.

Girl question of the day:

Since the main power to the harness is supplied at the starter could the starter solenoid overload that fuse? yes, the starter cranks...

Just a shot in the dark....

 

[89Suburban]

How about the vehicle speed sensor? I see a diagram that shows that a wire from that fuse going to the speed sensor. Is that disconnected?

As far as your last question if there was a short in the feed wire going to that fuse I would imagine a fusible link in the engine compartment would go bad.

Do you know what the RPO code for your engine is?

 

[HotRodPC]

Ok.... I've been up, over, under every wire... nothing frayed, burnt, exposed, etc.

Girl question of the day:

Since the main power to the harness is supplied at the starter could the starter solenoid overload that fuse? yes, the starter cranks...

Just a shot in the dark....

Keep in mind, a wire doesn't necessarily need to be burnt or exposed. All 2 wires have to do is get warm enough to melt the coating and then they become one. It only takes 1 wire getting warm or hot enough and it'll melt the coating to the wire or wires next to it. This can happen in a ribbon of wires or a bundle of wires.

 

[Jims86]

Proper way to do it, with everything unplugged, is to do a continuity check between the pink/blk wire, and chassis ground. If you dont get a short there, thankfully, its one of the components.

 

[CWGRL]

Thank you Everyone

First, I want to say "Thank You" to all that helped with this post.

It's greatly appreciated!

Finally, I found the short!

The wire harness that sits behind the check valve was shorting out on the check valve tube...

What a flippin adventure & learning process!

Thanks again, Everyone!

 

[RetroC10Sport]

Yay!!!

 

[89Suburban]

Give that lady some reps!!!!

Thanks for reporting back! I was reading this thread today wondering what was going on on the other side of the line.

You must be registered for see images attach

 

[Jims86]

First, I want to say "Thank You" to all that helped with this post.

It's greatly appreciated!

Finally, I found the short!

The wire harness that sits behind the check valve was shorting out on the check valve tube...

What a flippin adventure & learning process!

Thanks again, Everyone!

Cool!
Like in post #35? when you say check valve, where is it located?

 

[MrMarty51]

Cool!
Like in post #35? when you say check valve, where is it located?

 

[HotRodPC]

That's Great. Whooda Thunk it??? That's the thing with a short. You just never know.

I had a problem on my 93 Ford Box Van. I was losing my OD Cancel Light Button Feature in the end of the gear shift lever, the back up lights, and the turn signals. Finally found the fuse. Replaced it. Blew again about 10 miles later. Replaced it. 5 miles later Blew Again. Lucky for me when I decided to trace it down, I had a bit of a clue the that issue went to the rear and under the truck. I found a wiring harness had come loose, had been sagging and rubbing in the driveshaft to the point it wore the rubber coating off a wire and everytime that wire swung into the driveshaft every so slightly, Poof !!! I blew the fuse. Taped it up but the 6 wire loom in some of that flexible plastic tubing and zip tied it to the bottom of the box of the truck.

 

[dhamp]

First, I want to say "Thank You" to all that helped with this post.

It's greatly appreciated!

Finally, I found the short!

The wire harness that sits behind the check valve was shorting out on the check valve tube...

What a flippin adventure & learning process!

Thanks again, Everyone!

Glad you finally found the gremlin! Got a pic of the location?