esof - 4hi works, 4lo doesn't. couple questions - Ford Powerstroke Diesel Forum
User Tag List

LinkBack Thread Tools Display Modes
post #1 of 1 Old 04-05-2013, 05:57 PM Thread Starter Rookie
Join Date: Mar 2011
Location: Thunder Bay Ontario
Posts: 13
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Thanks: 0
Thanked 0 Times in 0 Posts
Feedback Score: 0 reviews
esof - 4hi works, 4lo doesn't. couple questions

I'm not super familiar with these trucks.

It's the truck in my sig.

Do 03 trucks have GEM modules? I am fairly sure my 4wd system is run through the 4wd module behind the glove box. At least, I have some sort of module back there.

I've checked my relays, and clearly power gets to the motor and the motor shifts it to 4hi. So I'm inclined to think all that works. shift motor, relays, etc.

Truck will start in any gear though. Also, I have phantom interior issues. The door light works, but using the switches for the dome lights sometimes works, sometimes doesn't. Door chime sometimes works, sometimes doesn't. I'm wondering if the truck has a GEM maybe it's that. If it controls the relays.

Also, neither the 4hi nor the 4lo lights illuminate when starting the truck when all the lights are supposed to momentarily illuminate. They used to, but don't anymore

Other possibility is a broken range sensor wire or neutral safety?

I'm yet to nail down a wiring diagram for the 4wd system for my year truck.

Someone please point me in a direction here. This has been p***ing me off for almost 2 years and i've spent too much time troubleshooting my truck and too much time searching online to only come up empty handed.

2003 F250 SD 4x4 3.73 SCSB VE powered 12 valve Cummins , lots of motor power ups, NADP Heavy Hauler 4R100, PCS Controller, 4" Lift, 35" BFG MT. Somewhere north of 400hp

Last edited by rlebar; 04-05-2013 at 07:15 PM.
rlebar is offline  
Sponsored Links

Quick Reply

Register Now

In order to be able to post messages on the Ford Powerstroke Diesel Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Please enter a password for your user account. Note that passwords are case-sensitive.


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:


Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.

Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode

Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

For the best viewing experience please update your browser to Google Chrome