Electrical problems -- 4.2L - Ford Truck Enthusiasts Forums


Electrical problems -- 4.2L

Old 12-04-2007, 04:14 PM
arch07 is offline
New User
Thread Starter
Join Date: Dec 2007
Posts: 2
arch07 is starting off with a positive reputation.
Question Electrical problems -- 4.2L

My coworker has a '97 F-150, 2 WD, 4 speed w/ OD, that has 242000 miles on it. The truck ran perfectly until a couple of weeks ago. The first problem that showed up was the heater fan would continue to run after the truck was turned off and the key removed from the ignition. Then we tried the turn signals and the wipers and they would also operate after the key was removed. Then the truck started shutting off while driving. Have noticed that this usually will occur at low rpm's or idle, not while running down the highway. When it shuts off, it will not restart unless the key is turned to the OFF position. If you try to restart it (after it shut down by itself), by turning the key to START, it will turn over but won't fire. Turn the key to OFF and then to START and it will fire right up. Just 2 days ago the speedometer started acting up. It will fall to zero even at 30-40 mph, and then it will start to fluctuate like there is a contact problem.

Have replaced the key switch, but the problem still remains.
Any and all help will be appreciated.
Old 12-04-2007, 04:20 PM
ford dr.
ford dr. is offline
Freshman User
Join Date: Feb 2007
Location: near b'ham al.
Posts: 30
ford dr. is starting off with a positive reputation.
Check the GEM module for codes. If it has bunches of codes in it, remove the central junction box and gem and seperate them. If you see corrosion, replace both and reseal windshield.
Related Topics
Thread Starter
Last Post
1994.5 - 1997 7.3L Power Stroke Diesel
02-16-2015 05:42 AM
1999 - 2003 7.3L Power Stroke Diesel
04-01-2013 08:29 AM
1999 - 2003 7.3L Power Stroke Diesel
12-03-2012 07:56 PM
1980 - 1986 Bullnose F100, F150 & Larger F-Series Trucks
02-23-2011 11:44 PM
6.0L Power Stroke Diesel
01-07-2010 02:15 AM

Thread Tools
Search this Thread
Quick Reply: Electrical problems -- 4.2L

Contact Us About Us Archive Advertising Cookie Policy Privacy Statement Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.