Complete Loss of Power - All Systems

[Lonnie-S]

On Thursday, August 11, 2022 after a run to the beach and hardware store, my 2002 Sport Trac was parked at home and turned off for a couple of hours.

Later on, I went to start the truck again. Upon turning the ignition key, some dashboard lights illuminated, but the starter did not engage. I tried turning the ignition switch off, making sure it was in park, my foot was on the brake, etc., and the tried the start position again a couple of times. Fewer instrument panel lights came on, and the eventually there was no response at all. No lights. No starter. No cabin lights. No headlights. No radio. Nada!

All systems seem to be without power. I did a few elementary checks on the battery and fuse box. The battery is about a year old and registers 12.54 Volts on my multi-meter. Power is getting the the main fuse box @ 12.54 Volts too measured on the (always hot) main circuit trace. I measured to several empty fuse location spades and there was 12.54 Volts on them as well.

Visual inspection of the fuses did not locate a blown one. The main fuse to the circuits powering all the relays (50A) looks good and intact. Power is getting to the fuse box and power fuses. I have no way to test relays unless someone can give me an at-home testing method.

The next test recommended in the troubleshooting guide is to measure from the + side of the battery to the engine block grounding plate, supposedly on the cylinder head. I can't locate that. Does anyone know where it is located?

Has anyone encountered a similar problem?

The car is parked on the street, pointing downhill. I have to way to jack it up and get under it.

Thanks,

Lonnie

 

[spetersen]

Do your headlights work? If not, test battery voltage with the switch on. The engine block ground can be checked anywhere on the solid metal of the block, or heads, there is usually a wire, sometimes braided, from the frame of the truck, to the engine block.

 

[Lonnie-S]

Thanks for the input. No, the lights don't come on. I haven't tested the battery voltage with the light switch in the on position. I will do that.

What would it tell me if the voltage is other than the 12.54 volts shown on the multimeter with the lights off? Would it mean there is a big short in the lighting system?

Cheers,

 

[Lonnie-S]

I went out and checked. First, the battery voltage with the light switch off is 12.48 volts today.

When I turned the headlight switch on, and checked the battery again, it was still 12.48 volts, so no change.

I was puzzled with the voltage drop from 12.54 volts yesterday. I did notice that the "Theft" light in the lower right hand side of the instrument cluster is blinking, as it normally does when parked with the doors closed with the key fob switch.

So, at least the anti-theft system seems to be getting power, and may be operational, or at least monitoring things. That's very interesting. Can the anti-theft system shut off power to other systems in the vehicle?

 

[spetersen]

Sometimes a battery can show 12 volts until you put a load on it, with a load it may have been much lower, and have been a bad battery.
I have to find a schematic before I can make more suggestions. Did you check at the posts, or cables? Do your terminals look clean?
I don't think the anti theft disrupts anything but the starter circuit, and possibly spark and fuel.
Edit:
I found a partial wiring diagram for the headlights, it says they are always powered, so with the headlights on, measure fuse 24 under the hood.
If there is no power there, the problem has to be from the battery to that fuse.

 

[Lonnie-S]

Sometimes a battery can show 12 volts until you put a load on it, with a load it may have been much lower, and have been a bad battery.
I have to find a schematic before I can make more suggestions. Did you check at the posts, or cables? Do your terminals look clean?
I don't think the anti theft disrupts anything but the starter circuit, and possibly spark and fuel.

I checked voltage at the battery posts. The battery is just a year old. That doesn't mean a cell (or more) couldn't go bad, but it's a high-end battery, and I think it's likely good.

I installed the battery myself. I did a complete scrub and clean (wire brush + baking soda solution) to the cable ends, then sealed them after installation. They' looking really good.

I actually have the wiring diagrams for the truck, but I'm not really an "electrical guy", and really struggle to decode the info in them. One thing I've wondered about is the ignition switch itself. I wiggled it because I know how fussy the Ford switches can get when they're old. It doesn't seem as sloppy as some of the Fords I've had, but if it's no good, I wondered if that could be the issue? It doesn't seem like a bad one should turn all systems off, though.

 

[spetersen]

When I looked at the headlight diagram, the headlights do not go through the ignition switch, that was why I tried the headlights first.

 

[Lonnie-S]

I found all the empty spades in empty fuze locations (under the hood) had battery voltage. It's one continuous metal buss, so power is getting to the fuses in the engine compartment (photo in first post).

However, this situation is a moving target. Here's why. When I went out to look at the cabin fuse block, the one on the side of the dash revealed when the driver's door is open, I could hear a clicking sound in the dashboard. It turned out to be the radio, which also has a CD slot and a tape player. It turns out the CD player was trying to eject a non-existent CD because it was empty.

Interestingly, there are two fuses associated with the radio system. I removed both of them. The CD kept clicking anyway. I kept pulling fuses, looking for any the were blown, but found none. They're all fine.

However, when I remove fuse #24, a 7.5A fuse for the GEM (General Electronics Module?) the clicking stops on the CD player. However, immediately thereafter, something in the engine compartment started clicking. I could hear the clicking clearly, but couldn't' locate it. I had to remove the positive cable to make it stop.

So, now I'm off to discover what the GEM is, where it's located. I know so far it does control the starting system immobilizer. It's dark out , so it will have to wait until tomorrow.

 

[Turdle]

Have you cleaned the battery posts?

Even if they look clean, it sounds to me like they are not making connection. Take the terminals off and clean them and posts with a wire brush. Put it back together dry, no post grease

 

[spetersen]

I found all the empty spades in empty fuze locations (under the hood) had battery voltage. It's one continuous metal buss, so power is getting to the fuses in the engine compartment (photo in first post).

However, this situation is a moving target. Here's why. When I went out to look at the cabin fuse block, the one on the side of the dash revealed when the driver's door is open, I could hear a clicking sound in the dashboard. It turned out to be the radio, which also has a CD slot and a tape player. It turns out the CD player was trying to eject a non-existent CD because it was empty.

Interestingly, there are two fuses associated with the radio system. I removed both of them. The CD kept clicking anyway. I kept pulling fuses, looking for any the were blown, but found none. They're all fine.

However, when I remove fuse #24, a 7.5A fuse for the GEM (General Electronics Module?) the clicking stops on the CD player. However, immediately thereafter, something in the engine compartment started clicking. I could hear the clicking clearly, but couldn't' locate it. I had to remove the positive cable to make it stop.

So, now I'm off to discover what the GEM is, where it's located. I know so far it does control the starting system immobilizer. It's dark out , so it will have to wait until tomorrow.

That fuse was in the passenger compartment? I was talking the engine bay fuse 24(headlights) If the headlight fuse has power, the headlight have to work, as I understand the system, there is no relays or computer control of the headlights in this model generation

 

[Lonnie-S]

@Turdle

I cleaned the positive cable and put it back on yesterday. Mostly, I did that because I thought if I disconnected power, something might reset itself, and maybe I'd get lucky with the whole system. It didn't happen. There's no harm in trying the ground cable today too. I'll do that.


@spetersen

I checked each fuse in the engine compartment (Ford calls it the Battery Junction Box) and they're all good. The lights do not go on. I'm going to pull the ground cable this morning, clean and remount it. Since I know for sure the positive side of the battery is providing power to the engine compartment power distribution setup (the Battery Junction Box), I do admit it sounds like a grounding issue. However, as I mentioned some electronic items (CD player, anti-theft system, the thing clicking in the engine compartment) have power, which contradicts the grounding issue in part. There are multiple grounds, so it's not impossible that some things might work if they have a good ground while others using a different ground don't work.

I don't have a code reader, so I can't check for fault codes. I've scheduled the car to be picked up and taken to a repair shop on Tuesday morning. It's my daily driver, so I need it to work. I'll keep trying on my own until then.

 

[spetersen]

Has it been fixed? What was wrong?

 

[Lonnie-S]

Yes, it was fixed. It turned out that the main power cable to the starter was grounding out on the frame. The cable had been rubbing for some time, and the insulation wore through. It was in an area you could only see when the car was up in the air, which I couldn't do at the time. The cable was replaced and secured, and all is good.

Once the cable was replaced, it started right up.

 

[spetersen]

Thanks for the update!