Intermittant complete elecrical outage

Hey guys, I'm not an electrical whiz so help me out with this one.

From time to time, say every couple days or so, I'll be driving along and for a split second my entire electrical system shuts down. The engine stutters, the radio goes dead, the "!" Actung sign comes on, etc. All of this just for a second, and then everything is back to normal as though it never happened.

Sometimes/mostly it happens when I go through a slight dip in the pavement and the car is pressed down a little for a second or so on the shocks.

A loose connection? What connection would make the whole electrical system blink?

Any ideas?

Andy

Check the battery terminals, maybe a clamp is loose. The constant power from the + terminal going to the fuse box may be something else to look at.

I would start with battery cables, in particular the main chassis ground.

Thanks guys, the clamp to the negative terminal did seem a little loose, so I tightened it. Pretty basic, I hope that was the problem.

Andy

Some thoughts!!

A car can run with its battery's positive or negative terminals disconnected, that's how I test alternators, remove one battery terminal and if the motor still runs, the alternator is OK.

Since the motor and alternator grounds are independent of the battery's ground, an interruption in the battery's ground should not affect the motor unless you were ruining AC, lights, E.T.C. and the alternator could not power the car without the battery.

Bad battery terminal connections normally prevent good starting but don't prevent the motor from running.

The alternator, battery and starter all share the same positive circuit that then goes to the fuse box. Check continuity from battery to alternator, battery to fuse box, you should wiggle those wires while testing.  A bad connection from battery to fuse box could cause total failure.

Also, if your positive wires meet at the battery as shown in the diagram, make sure that are well connected because that is the distribution point shown in the diagram.

Here is the wiring diagram for a 1984 944, I am not sure if its different for an 86+. Take a look at the junction where all positive wires meet, you could be the problem where your main feed goes into the fuse box.

Thanks pormgb!

Andy