Hello all I am newb to the forum

So here is what is happening. #9 fuse (PCM Fuse) which is a 30a fuse will blow the around 10 seconds after i turn the key to the run position. I have check ever other fuse is the battery box and the junction box as well as tested all relays.

I can start the van with a new fuse but is dies after 5-10 seconds, i go check the PCM fuse and its blown.

Whats odd is in just the key in run, engine not running, it will still pop the fuse. Any suggestions as to where to start?

thank you
lostislandguy

 

So quick update.. I decided to pull some fuses and see if anything was amiss... So i got to fuse #23 Ignition Switch fuse and when I pulled it it didn't trip my 30amp breaker

Photo 1 shows the fuse in place and the PCM relay fuse tripped



Photo 2 shows fuse removed and the PCM fuse never trips




So where to go from here?
lost

 

Your symptoms strongly suggest something amiss in the ignition switch itself of the wiring for those circuits. I gather the KO position is where the problem begins which would lead me directly to one of the circuits associated with the "run" position.

Not too definitive I know but you're pretty much narrowed it down to which conditions blow that fuse. Assuming no other work, repair or modifications to any part of this van weren't done just prior to this, that until recently all was good it would tell me the column-mounted ignition switch itself could be at fault.

Given that age of the part I'd not be the least bit shocked knowing it was the cause of all this.

Please let us know what you discover---hope its nothing serious or expensive.

 

Your pictures show an aftermarket resettable 30amp breaker/fuse.

I bet you a donut there's some aftermarket electrical-something-else going on, and it's the cause of your problems.

What else you got on that truck?

 

I just re read it and realized you are referring to it as "PCM" fuse.

To me it appears non-stock. Does anyone know if I'm wrong?

 

That resettable fuse doesn't look stock to me either. Either way if it were me, I would start by replace it with a standard 30amp fuse and see if that fixes the problem. Any circuit breaker can go bad..

 

I pulled the fuse diagram for the '99 E350, doesn't agree with the photos?

 

Those without access or awareness of EVTM's, Owner's Manuals etc or how to best use them in a fault like this can't be sure how what's shown in a photo correlates to the actual van.

Regardless if its a fuse or a circuit breaker they're being interrupted due a problem appearing in the Key On/Run position. Because OP specifically mentions the 60 amp fuse shown and identified it as Fuse #23 consulting factory wiring info shows its related to the ignition switch.

Hopefully the OP can update us if help is still needed.

 

Is this a diesel? Glow plugs come to mind.

The CB is definitely not OEM. Ford labels CB's in the diagram but they are self-resetting types.

I would pull the PCM relay and test again. If it is the PCM itself, that would be the problem. Or wiring to the PCM.

How were the relays tested? Relays are often the same and interchangeable for testing purposes.

We do need more information. Troubleshooting from afar is tough. jim

 

The resettable fuse is for troubleshooting purposes, its not going to remain there once the issue is fixed, a maxi 30a will go in.

I still have the issue, just got back to working on the box truck today. I see mention of replacing ignition switch, you mean the lock cylinder?

thank you
(still) lostislandguy

 

No---the lock cylinder simply pushes a rod attached to the actual ignition switch. The ignition switch is a sliding contact device, attached to the underside of the steering column, a large multi-wire connector attached. This is it without the electrical connector:


HTH

 

its the same,i think cause maybe you dont see the full bank of fuses, also this is a v8 triton box truck? but truck ran fine for 8 months till it just died going down the highway a couple months ago. Would crank but no fire.

lost

 

JWA thank you for the explanation and reference photo, I now know what to trouble shoot next

I did some more detective work yesterday and pulled up the fuse bank to get a gander at the underside. So my issue is the #9 30a PCM/Battery box fuse keeps tripping when ignition it turned on. The underside revealed that the wire running from #9 splits and goes to fuse #4 PCM keep alive, I was able to determine that the when key on, #4 is getting power and not popping the 10a mini fuse, so I can rule that out. #9 also goes to G, the PCM Relay. Tested relay and it is fine.

So here is my new discovery if i unplug the PCM Relay (G) and reset my #9 fuse and turn the key to the on position it doesn't trip the #9 fuse. I did swap relays just to make sure it wasn't a bad relay, but that had no difference.

So here was a little test i did, with G relay out and #9 reset, I turned key to on position, and again #9 test fuse didn't trip, so with key in on position i inserted the G (PCM) relay, heard it click and in 5-10 seconds it popped my #9 test fuse.

So I think fuse #23 never popped during all my testing so and is not wired in the box to #9 or the PCM Relay. So i think its fair to say I can rule out #23 (possibly).

Moral of the story is when PCM Relay (G) is out and #9 fuse is reset and key in on position, the #9 fuse never pops. With key still in on position i insert G Relay and it pops the #9 fuse. So the G relay seem to be what is popping my #9 fuse.

Now question, where do i go from here?

Thank you all for the help
Lost

 

my #9 fuse it a test, resettable fuse, testing purposes only, was a normal blown maxi when I started troubleshooting. Won't effect the testing process just saves me from having to but 100 30A Maxi fuses

Lost

 

You need a factory EVTM for your year & chassis. While the detective work is all well and good an actual schematic showing the various electrical sub-systems and all interconnecting wiring would probably be the easiest route to tracking any wiring issues down.

Here's a few, cheap and beat up to very nice, priced accordingly:

1999 Ford Dealer Electrical Wiring Diagram Service Manual Econoline Club Wagon | eBay

1999 Ford Econoline Club Wagon Truck Wiring Evtm Manual | eBay

HTH