Re.: Electrical systems dead

George you are right for sure.where were you , not showing up at Dublin.. I was hoping to meet you.regards, Art

Ken read all you want--if a PO left factory spec. then you will not find it--one of the reasons I encourage folks to keep their cars stock.

Friends,

The problem was a battery cut-out switch in the trunk.

Apparently it was moved when the clerk loaded the groceries.

Four days and a tow for a simple switch.

Gotta read up more before I stumble into another foolish situation.

Thanks all,
Ken

George,

Looks like a factory disconnect switch is below the ignition switch.

Tried locking it in both directions without any change to the problem.
I'll trace it in the morning.

I've also fount something strange under the hood.
Over left wheel well are three about 1" cube electrical devices.

The rear one has no cover.
On its top-side are 4 solder joints.
One joint has a thin wire added, and ending in an alligator clip.
The clip is hanging loose..not connected to anything.

I don't recall seeing this loose clip when I replaced the spark plugs last week.

George,

Looks like a factory disconnect switch is below the ignition switch.

Tried locking it in both directions without any change to the problem.
I'll trace it in the morning.

I've also fount something strange under the hood.
Over left wheel well are three about 1" cube electrical devices.

The rear one has no cover.
On its top-side are 4 solder joints.
One joint has a thin wire added, and ending in an alligator clip.
The clip is hanging loose..not connected to anything.

I don't recall seeing this loose clip when I replaced the spark plugs last week.

There wasn't a "factory" disconnect switch....must be something that was added on. Definitely worth tracing.

The cube thingies are relays...I'll have to look up what each for for. The one that is opened up will need to be addressed but the first thing is to determine why you don't have voltage on the two firewall junction posts. All power for the car is distributed from those posts.

Cheers
DD

George,

Looks like a factory disconnect switch is below the ignition switch.

Tried locking it in both directions without any change to the problem.
I'll trace it in the morning.

I've also fount something strange under the hood.
Over left wheel well are three about 1" cube electrical devices.

The rear one has no cover.
On its top-side are 4 solder joints.
One joint has a thin wire added, and ending in an alligator clip.
The clip is hanging loose..not connected to anything.

I don't recall seeing this loose clip when I replaced the spark plugs last week.

Ken forget door switches and fuses--You need to direct all of your attention to the heavy battery cables both positive and ground. Is there any chance the car has a battery disconnect on it? Total dead is a large cable failure or battery but you say it is good.

Jim,

"Electrical systems dead" as in nothing has power.

First time this has happened.

Pretty sure it has something to do with the driver's door inside lock switch.
First time I had tried using it.
Had turned the ignition switch off.
Moved the door switch back and forth a few times.
Tried starting the engine right after that, and all power was dead.

Doug,

The battery connections check OK.

The two posts on the firewall are dead.

My next move is to check all the stuff mounted on the right rear body support next to the battery.
Looks like the + connects to a metal box on the right-side of that body support.

I do have a fresh copy of the XJS repair operations manual.

Can you describe "dead" in more detail

1) Do the dash lamps illuminate when you insert and turn the key?
2) Does the engine crank?
3) Do the headlights work?

If the headlights are not working that could definitely be a bad battery lead.

If you're not getting any signs of life that points possibly at the ignition switch. I don't know the electrical layout in that car but with a wiring diagram you should be able to verify the various circuits are energized.

If you're getting lights on the dash and headlights but no action, that could indicate a dead starter solenoid. If you know how to do this, short the starter by taking the power lead and connecting it to the solenoid start terminal using an insulated tool to verify starter operation. Don't have the key in the car when you do this. You don't want it to start running while you're under it.

I don't know that car but had a problem with my own that could have been described like that. My car could die at an intersection. The status lights would illuminate and it would crank but it would not fire or run. Sometimes. That turned out to be the main power relay which functioned by had burned contacts. The easy way to locate this, as opposed to what I did, is to open the electrical panels and swap identical relays to other locations. There's only a few relay types so finding a place to swap it to is pretty easy. The problem should follow the bad relay.

Also, while you're at it check all your fuses. Shrug. It's unlikely but worth the effort.

That's a few easy things to try that may settle what's going on.

Begin with the easy things: check the cables at the battery for cleanliness and tighteness. Trace the ground cable and make sure the other end it tightly attached to the body.

The "+" voltage goes forward to two "+" junction posts on the firewall. Power is distributed from these posts. Make sure the conenctions are clean and tight. You'll have to look a bit to find them. Look on the firewall just aft and slightly below the rear of each intake manifold.

Cheers
DD