Ok, I've searched and searched and I don't even know what to do anymore

Here are my problems with my truck. I don't know where to begin looking.

Oh and my truck is a 2003 SCSB 7.3 Auto with ESOF.

Went through some water 2 years ago and 4 Lo stopped working. 4 High still works fine. 4x4/4lo dash lights dont usually go on with initial key event like they should. 4x4 light does work when 4high is engaged

Interior dome light switches won't work 95% of the time. If I open the door and close it sometimes they work. The middle dome light works fine when I open the doors

Radio doesn't work with key in accessory, only works with key in run position

Ford factory fog lights have no power going to them, thus they don't work. Bulbs are intact

Truck will start in ANY gear.

Sometimes the remote door locks don't work.

Factory remote start does everything except actually start the truck.

Last time I hooked a trailer to the trailer brake plug the radio would not shut off even when the truck was turned off and the key removed.

I read about the GEM and stuff but I read my truck doesn't have one. it has a VSM? I don't know what that is. Could all these issues be rooted back to one specific item or?

Anyone with any form of insight would be nice. I've been beating my head with this for a long time and spent crazy amounts of time searching online for answers. I'm just not familiar with ford electrical. I'm more of a 3 wire kind of guy...

 

Sure it's not a Chevy?

You have one busy electrical gremlin. Could be VSM (located behind the radio) or could be as simple as bad grounds or cables. Take a peek for corrosion on the cables.

Plenty of more experienced guys here, one will be along shortly.

Welcome to FTE!

 

thanks!

I'm fairly certain it's not the grounds unless there is a ground or couple of them I don't know about.

I did find this: (excuse me here I'm editing these in to help me trouble shoot my 4wd)

https://www.ford-trucks.com/forums/1...x4-relays.html
https://www.ford-trucks.com/forums/1...t-working.html
https://www.ford-trucks.com/forums/1...w-bad-pcm.html

I did check my hi/low low/hi relays but I may have checked wrong. I don't know how it would be the relays if it shifts in to and also out of 4 hi but anyway.

I am wondering if it's the 4wd module.

What is the "proper" method of putting the truck in to 4low?

I always come to a stop, take my foot off the brake, put it in neutral and flick the esof switch. I've also tried the same method with my foot staying on the brake but I get the same result

EDIT:

The blower motor just quite on me today now too. Doesn't work at all. F off...

 

Owner's manual:

To prevent damage, the electronic shift 4WD system is designed
to allow up to 45 seconds before the shift command is performed.

Shifting from 2WD (2WD high) to 4x4 HIGH (4WD high)
Rotate the 4WD control to the 4x4 HIGH position at speeds up to 88
km/h (55 mph).
•To prevent damage, the electronic shift 4WD system is
designed to engage 4x4 HIGH (4WD high) when the vehicle
is moving. If the 4x4 indicator light does not illuminate when
shifting a vehicle that is stationary, start the vehicle
moving. Once the vehicle is moving, 4x4 HIGH (4WD high) will
engage and the 4x4 indicator will illuminate.
Do not shift into 4x4 HIGH with the rear wheels slipping.
Shifting from 4x4 HIGH (4WD high) to 2WD (2WD high)
Rotate the 4WD control to 2WD at any forward speed. Disengagement
of the transfer case and front hubs may be delayed due to torque bind
which is caused by driving on dry hard surfaces or performing tight
turns while using the 4WD system.
•Youdo notneed to operate the vehicle in R (Reverse) to disengage
your front hubs.
Shifting from 4x4 HIGH (4WD high) to 4x4 LOW (4WD low)
1. Bring the vehicle to a complete stop.
2. Depress the brake.
3. Place the gearshift in N (Neutral) (automatic transmission) or depress
the clutch (manual transmission)
4. Move the 4WD control to the 4x4 LOW position.
5. Hold the shift command until the LOW RANGE indicator light
illuminates.
6. If the LOW RANGE indicator light does notilluminate after 15
seconds, start the vehicle moving, then repeat steps 1 through 5
before reporting any shift concerns to your dealer.
Shifting from 4x4 LOW (4WD low) to 4x4 HIGH (4WD high) or 2WD
(2WD high)
1. Bring the vehicle to a complete stop.
2. Depress the brake.
3. Place the gearshift in N (Neutral) (automatic transmission) or depress
the clutch (manual transmission).
4. Move the 4WD control to the 4x4 HIGH (4WD high) or 2WD (2WD
high) position.
5. Hold the shift command until the LOW RANGE indicator light shuts
off.
6. If the LOW RANGE indicator light does notshut off after 15 seconds,
start the vehicle moving, then repeat steps 1 through 5 before
reporting any shift concerns to your dealer.

 

Motorbug also will not go into low range.
I get 4x4 hi just fine... but i just get a clunk from the shifter motor and then my 4x4 disengages if i try to go in low range.

My AE was able to see codes for it but just as a circuit out of range fault.
Ill have to write down th3e code next time.

 

I just tried many times to engage 4low. It just won't go. Again, 4high works fine.

Also, my blower motor mysteriously started working again.... I've just been sitting in my truck with the key in the run position (not actually running) for the last 10 minutes and out of nowhere the blower motor kicked on and it's working perfectly fine again

Also, I don't have any vacuum problems. Vents work fine when I shift it into 4high.

 

Welcome to FTE! Stick around this place, you'll learn more about your truck than you ever knew possible.

As for your blower motor, if you need to replace it, it's very straightforward and not very difficult at all. There is a write up on this site from a guy who did his (I believe it was a 7.3L van, but it still applies).

 

I can't help but think that most of these electrical problems are tied together.

And ya thanks. That's the hope. I wanna learn. I know most of the mechanics of the truck well, just not the electrical. I joined powerstroke.org and don't really ever get any help. That forum doesn't seem to have much activity. Hoping to have better luck here!

 

How are you at reading diagrams? I have several versions of that circuit, but I'm not sure which works with the 2003.

 

The fuses check out based on that diagram. The power to the relays at 86 and 87 do as well. I can only assume since 4high works for taking it in to and out of 4wd that that all check out.

I've already basically checked every single fuse on the truck and the relays. The motor works because it puts the truck in 4 high and takes it out. There is no power going to the motor for 4 low. And the relays aren't operating for that either. I'm thinking it has something to do with either the range sensor wire or the brake wire. And less likely but possibly the esof switch itself or the module.

What's the best way to test the brake wire and the range sensor wire? Can I test them at the plug to the module? What am I testing for if I do?

 

This might help: [LINK]



As I read this, the relays should flip-flop. One relay is on to switch it to low, and the opposite relay is on to switch it to high. Each relay provides half of the signal to the motor (pins 1 and 2 on the motor).

• Going to high has the low-to-high relay applying 12V on pin 1 and the high-to-low relay applies ground on pin 2.
• Going from high to low reverses the whole process.

If either relay is bad, you don't get a completed circuit to the motor. If the motor gets both 12V and ground with no noise, forward and reverse - bad motor.

The ORG/LT BLU wire gets a ground signal when the motor should go from High to Low.

The BRN/WHT wire should get a ground signal when the motor should go from Low to High.

 

Oh so the relays don't take effect from 2wd to 4hi and back to 2wd? Only from high to low, and low to high? Hm... I didn't know that. Should have put 2 and 2 together on that though... They are called hi/low low/hi relays. I am pretty sure I switched them before with no effect, but I will try again. If thats the case, both relays could be bad too and I don't have spares. Might have to buy one and see if it works. Then buy the second relay as well if I can get it to work

 

Ok I have 3 relay boxes under the hood.



The top one is for 4wd. All 4 of the big relays between the 3 boxes have the same pn# and I had a spare one in the glove box as well. That makes 5. I tried all 5 for the hi/low and low/hi. None worked. I wasn't able to tell if the relays clicked or not as I didn't have any help. I wasn't able to check voltage to the motor. I did all this last year as well but had help and I wasn't getting voltage to the shift motor nor was I getting power through the relays to the shift motor. The relays weren't clicking

As an aside, what are those other 2 relay boxes for? The top of the picture is the firewall

 

Continuity through the switch checks out

Also.

"The ORG/LT BLU wire gets a ground signal when the motor should go from High to Low.The BRN/WHT wire should get a ground signal when the motor should go from Low to High."

Where do those wires get grounds from?

 

Ok, switch checks out. Continuity through it is fine.

Relays check out. I hooked a ground jumper to the 4wd mudule end of both the br/wt wire and the or/bl wire and got the shift motor to go in both directions. Confirmed with the 4low dash light and all.

So as of right now I've ruled out the shift motor, esof switch, relays.

So the problem lies in the 4wd module, or wherever it gets ground for the 2 hi/low and low/hi wires. I could run a 3 way switch and eliminate all this BUT I really don't want to do that. I would rather figure out the problem and have it work properly for me again. plus I would hate to accidentally bump the switch and have it try to shift to 4lo at a really bad time...

Are the triggers to the 4wd module for neutral on the range sensor and brake pedal, grounds? How can I test them?

And my 4wd system diagram shows an ESOF solenoid. Where is that located and how can I test that?