4wd lights blinking

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Mar 23, 2007 | 07:09 AM

PSKSAM2

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Laughing Gas

Joined: Mar 2003

Posts: 940

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From: Morris Plains, NJ

4wd lights blinking

On my short drive to work this morning, the "4WD High" and "4WD LOW" lights started blinking. I was in 2WD from the time I started up. I've used the 4WD to get through a few sticky (actually, they were not so sticky) situations this winter, and it engaged fine. When I got to work, I tried flipping the switch and nothing happened (didn't engage), except for the periodic blinking.

Any ideas on what this means? Bad relay? Bad Wiring? Bad Tcase? Is it blinking a trouble code pattern at me? If I blink back at it, will it help?

I'm sure I've seen a previous thread on this, but couldn't find it in the search. If you have a link to a good thread on the topic, please let me know.

-Jim

Mar 23, 2007 | 12:39 PM

Rockledge

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Joined: Jan 2003

Posts: 9,748

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From: Connecticut

Jim, it sounds to me like a problem with the T-case or related circuitry. Here's what Ford says could cause problems:

- 4WD mode switch.
- Electric shift relay.
- Electronic shift control module.
- GEM.
- Circuitry.
- Transfer case shift motor.
- Transfer case electric clutch.
- Transfer case mechanism

Have you checked the fuse(s) and relay(s) related to the 4WD system?

The GEM monitors the 4WD system for errors and stores diagnostic trouble codes in memory. Unfortunately, you need a fairly sophisticated scanner to access these codes.

Mar 23, 2007 | 02:26 PM

PSKSAM2

Thread Starter

Laughing Gas

Joined: Mar 2003

Posts: 940

Likes: 2

From: Morris Plains, NJ

Joe,

Thanks for the places to check. I haven't looked at a thing yet, it only did it on the way to work this morning.

Do you think I'm hurting anything by driving around in 2wd?

-Jim

Mar 23, 2007 | 06:47 PM

crazypaw

Senior User

Joined: Feb 2006

Posts: 311

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From: Ellington, Connecticut

Possible Short

Hi,

With all the garbage weather that we have have had here in the N.E. (NJ+CT included) I would be inclined to say that is an "electrical shorting" condition that exhists.

Mar 24, 2007 | 07:41 AM

PSKSAM2

Thread Starter

Laughing Gas

Joined: Mar 2003

Posts: 940

Likes: 2

From: Morris Plains, NJ

I think you may be right crazypaw. When I drove home from work yesterday, the problem had solved itself. The lights acted normal (came on, then went off) when I started, and didn't blink at all. I tried the switch and it seemed to shift into 4wd High just fine.

I guess I'll keep an eye on it.

-Jim

Mar 24, 2007 | 10:41 AM

fflintstone

Elder User

Joined: Feb 2007

Posts: 771

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From: Aurora

Just a thought Sam, but those switch lights will just sit there and blink at you in you depress them and the conditions aren't right for actuall 4X4 engagement. Like when the proper procedure isn't followed for goin into 4WD. I've done it myself when I inadvertantly hit the 4LO button with my knee. It flashed untill I hit the 2High button.

Fred

Mar 24, 2007 | 05:34 PM

PSKSAM2

Thread Starter

Laughing Gas

Joined: Mar 2003

Posts: 940

Likes: 2

From: Morris Plains, NJ

Thanks for the thought, Fred. My switch would be pretty hard to bump with my knee, and when this first occurred, I hadn't tried to move the switch.

-Jim