Another 4x4 "wont work" thread

[exalteduser]

94 blazer
4.3 multiport or whatever its called, NOT tbi

this truck has the push button 4x4 on the left side of steering wheel.
Something is amiss...

1. if in park, nothing happens either button
2. if in drive nothing happens either button
3. if in neutral, push 4hi then both lights flash a few times(hear a click like a relay somewhere) and then lights shut off. sometimes both will stay on but no 4x4 engage.

4. in the above method if i get both to light up, from there i can hit 4lo and i feel it lock in at the hubs, and 4 lo will work. only after messing with 4hi first. sometimes i cant get it back out of 4 lo right away.


I have heard everything from vacuum lines under the battery to modules and everything in between.
what i do know is it will lock in to 4lo with a little patience.

Previous owner mentioned that he would unplug battery for 5 minutes and then 4hi would work. i didnt try it exactly that way but i did try after i had it disconnected one time and still no go.

So i dont really know where to start, since it will work *sometimes* i feel like its a electrical or computer issue.

Thoughts, suggestions, Solutions, All welcome.
Thanks

[MT-2500]

Pull codes.
Ground pin 13 and turn on key and count 4W lighth flashes.

[exalteduser]

sorry about the delay, net was down for awhile. as far as pin 13 goes, i assumed you were referring to the pin connector under the steering wheel where you can pull normal codes. if thats the case mine only has 12 pins total, none of which are numbered. So if anyone knows which one that would be great. (1994)

[MT-2500]

Originally Posted by exalteduser

sorry about the delay, net was down for awhile. as far as pin 13 goes, i assumed you were referring to the pin connector under the steering wheel where you can pull normal codes. if thats the case mine only has 12 pins total, none of which are numbered. So if anyone knows which one that would be great. (1994)

Yes the diagnostic connector.
Ok you have OBD1. 12 pin connector.
You will need to ground pin J to get codes.

J should be half way between H and M as in link below.
http://www.troublecodes.net/GM/

Post back what code you get from 1 2 3 0r 4.

[exalteduser]

Thanks, turns out pin j was empth so i tried pin I next to it and that was the one. turned key on and both lights went in a seemingly endless loop of : flash flash pause, flash flash pause
so im guessing thats the 2 code.

[MT-2500]

Originally Posted by exalteduser

Thanks, turns out pin j was empth so i tried pin I next to it and that was the one. turned key on and both lights went in a seemingly endless loop of : flash flash pause, flash flash pause
so im guessing thats the 2 code.

Code 2 is for a encoder motor or circuit fault.
Best to get a repair flow chart for the code 2 and go all of the way threw it before throwing a encoder motor at it.

A good factory repair maunual or a ALL DATA ONLINE SUB HAS THE REPAIR FLOW CHARTS.
Be sure to check all voltage and wiring circuits and grounds
http://www.alldata.com/products/diy/index.html

Good Luck
And let us know how it goes.