1997 Ford F-150 4WD Axles Won't Lock

1997 FORD F-150
Avatar
PDC247
  • MEMBER
  • 1 POST
I am having trouble trying to ge my truck into 4 wheel drive. I have a manual transfer case and it will go into 4X4, but the vacuum is not switching over to lock the front axles. What causes that solenoid to switch over, and where is the relay located for the transfer case clutch?
Feb 23, 2007 at 12:51 AM
Advertisement
Avatar
CHEVY22
  • ✓Experienced Mechanic
  • 1,375 POSTS
there is no relay but there is a fuse in the junction block , #23 10 amp should be hot at all times, the fuse runs to both the 2wd and 4wd solenoids and to the gem module,besides that there is a vacuum reservoir in the engine compartment and a check valve in between there and the engine, the only other component involved is an actuator on the transfer case , i would start at the fuse and work from there checking vacuum to the units making sure you have vacuum from the engine to the res , if all else fails it may be the gem module , but i always say start simple and check everything three times , good luck on the hunt
Feb 23, 2007 at 4:54 AM
Avatar
CHEVY22
  • ✓Experienced Mechanic
  • 1,375 POSTS
uh oh im sorry i did find a relay behind the center of the dash , sorry
Feb 23, 2007 at 5:03 AM

Suggested Repair

Start with junction-block fuse 23 (10 amp, hot at all times), which feeds the 2WD and 4WD solenoids and GEM module. Check engine vacuum to the reservoir, the check valve, and the transfer-case actuator. Also inspect the relay behind the center of the dash; if those checks pass, the GEM module may be at fault.

Conversation Summary

A 1997 Ford F-150 with a manual transfer case shifts into 4x4, but vacuum does not lock the front axles. The owner asked what switches the solenoid and where the transfer-case clutch relay is. The expert first said there was no relay and advised checking fuse 23, vacuum supply, the reservoir and check valve, the transfer-case actuator, and possibly the GEM module. The expert then corrected that a relay is located behind the center of the dash.

Related Repair Questions

Add a reply
Join 2CarPros for free, one of the most advanced car repair communities on the internet. From first-time drivers to seasoned mechanics, everyone is welcome to reply, share details, and get better answers. You can add a temporary image or video first; uploads are limited to 20 MB.

Ask a new question

Frequently Asked Problems for This Vehicle