Car shut off at 40 MPH... Need electrical help.

[6o4turbo]

So basically, car was running normal (BPU 89' Turbo) I had been driving for about 10 minutes, the car was warm. I'm in 3rd, going about 40 MPH, when out of nowhere, the car loses all power. My tach and speedo drop to zero. All my electric Defi gauges freeze in place (EGT, Boost, FP, Oil pressure, all in good ranges), the car slowly dies as I turn off on a side street.

I popped the hood. Checked my fuses, couldn't find one that was blown. Checked battery connections, tight, look good. Batt voltage showed 12.5 V on the voltmeter, good.

No response whatsover ever when I turn the key, lights aren't working, ZERO POWER.

So where does this leave me? I towed the car home.

Did my ECU short out? Fusible link? Bad ground? Loose wire/bad connection somewhere else? Where is the best place to start tracking this down?

Thanks in advance,

- Kev

 

[CRE]

Did my ECU short out? Fusible link? Bad ground? Loose wire/bad connection somewhere else? Where is the best place to start tracking this down?

sorry, my keyboard died tonight... on screen sux. try the fusible link first

 

[6o4turbo]

Okay, so I started to trace my power wire back from the battery, and I got to some corroded/broken wiring, bingo.

I repair the wire.

I got to recconect my negative battery terminal, the second it touches it blows my 100A fuse in my fuse box?

I grab another 100A fuse, put it in, does the same thing.

What's happening here?

 

[6o4turbo]

No one?

 

[Poodles]

the wiring broke for a reason, find it...

 

[CRE]

Well, the 100A link is a start, now find the short.

 

[jetjock]

Either ohm the disconnected battery positive cable to ground then look for the short or replace the 100 amp fuse with a light bulb. And old headlight will do. The bulb will be full bright but and will dim or go out when the short is found. That way you won't be going through fuses. Since the fault seems to be in the primary power wiring also try disconnecting the alternator B+ lead.

 

[Poodles]

could an alternator failure cause this?

there was someone that had their alt catch on fire before...

 

[suprahero]

If your alternator failed, you wouldn't be reading 12.5 volts. I think it would have drained your battery.

 

[plaaya69]

My 87 N/A did the same thing at the same speed on the highway after I did a 360:naughty: lol, It turned out that it was a bad battery.

 

[starscream5000]

Never heard of light bulb trick before, that's neat, and would save you money in fuses too.

 

[6o4turbo]

Either ohm the disconnected battery positive cable to ground then look for the short or replace the 100 amp fuse with a light bulb. And old headlight will do. The bulb will be full bright but and will dim or go out when the short is found. That way you won't be going through fuses. Since the fault seems to be in the primary power wiring also try disconnecting the alternator B+ lead.

So I did the light trick, with an old fog light.

After wiring in the light to the 100A fuse, I reconected the neg. Batt. Terminal.

The light came on, cool.

I then tried disconnecting the plug from the back of my Alt. The light went out... Does this confirm the short is in my Alternator, or alternator wiring?

Thanks for all the help guys.

- Kev

 

[6o4turbo]

Is it possible something inside my alternator has shorted out, causing this?

Or should I be focusing my attention on the wiring to and from?

 

[6o4turbo]

Found/fixed the problem.

A small part of the alternator wiring loom had melted, and shorted out the circuit.

Thanks all who helped.