91 4X4 Help

[tobler_creek]

My 91 EB 4x4 set two years in a shed not driven because of RA bushings and a drivers side widow that wasent working. We got it out and fixed every thing it needed. I noticed after storage the 4 wheel lights on dash would not come on. I checked wire and hit the switch motor with a dead blow hammer, checked all fuses, Had my wife try 4 wheel button with switch on. Also my factory radio quit during this period, radio dosent lite up eather. What is my next step on checking the 4 wheel operation? This truck only has 92K and runs and drives like new. Thanks in advance, Jim

 

[DeRocha]

Hi Jim and welcome to the site.

When you start the truck and press 4x4 High do you hear any relays clicking from the driver side trunk area? If you do hear relays it indicates the switch and 4x4 computer are getting power and working (and the problem likely lies within the transfer case shift motor).

See the Shift motor rebuild for lots of info and pics on getting the shift motor working.

 

[tobler_creek]

91 EB 4x4

With ignigition switch on and wife pressing 4x4 switch I hear nothing. Could it be a bad relay? Where is it located? Thanks again, Jim Also as I said no 4x4 lites on dash switch.

 

[cgriffin_5139]

With ignigition switch on and wife pressing 4x4 switch I hear nothing. Could it be a bad relay? Where is it located? Thanks again, Jim Also as I said no 4x4 lites on dash switch.

Hi Jim and welcome to the site.

When you start the truck and press 4x4 High do you hear any relays clicking from the driver side trunk area?

^^^^

 

[mikeinri]

Lots of info for this problem on this forum. Do a search using the tool above.

There's a control module in the cargo area, behind the plastic panel on the driver's side. It's basically forward of the rear washer fluid reservoir.

Mike

 

[DeRocha]

With ignigition switch on and wife pressing 4x4 switch I hear nothing. Could it be a bad relay? Where is it located? Thanks again, Jim Also as I said no 4x4 lites on dash switch.

The relay noise maybe very subtle.. You may need to recruit your wife to sit in the rear driver side seat facing the trunk and listen as you press 4x4 High...

What does the 4x4 lights have to do with anything?
Operational wise this is what happens:
When you press the 4x4 High button a signal is sent to the 4x4 computer in the trunk area. The 4x4 computer reads input from the T-case geared sensor and if it is in 2H will energize the shift motor. When the Geared sensor has rotated into 4H the geared sensor contact for 4x4 will close causing both the button and dash 4x4 lights to come on.

Did you click the blue link on rebuilding the shift motor?? It goes into lots of detail on the various components of the 4x4 system.