How do you check power to the 4x4 module?

[rx-7ames]

Hi,

I am having 4 wheel drive problems in my 94 Ranger 4.0 with manual transmission and electronic transfer case. I followed the directions in another post to trouble shoot the 4x4 system. All my fuses are good so I checked the 4x4 module. I unplugged the 5 wire and 8 wire plugs, then with the key on I pushed the self diagnostic button. Nothing happened. I checked for power. I have power in the green wire all the time. The ground is also good. Am I supposed to have power through the purple/white wire too? I cannot find an answer to this and I am not real good at reading wiring diagrams. I would like to make sure I am getting power everywhere I should before I spend a lot of money on the control module. Those things are expensive.

Thanks.

 

[RonD]

You are using this article: http://www.therangerstation.com/tech_library/4wd_control_module.html

While/purple would have 12v with key on

 

[rx-7ames]

That is the article I used. I am not getting power from that wire at all. I guess that means the fuse for that wire is under the dash. Does anyone have a picture of which fuse this is? I do not have the fuse box cover or an owner's manual. I checked all the fuses though. Unless I missed something, I bet this is going to be a royal pain. I can't think of a good reason this wire is not getting power if all the fuses are good.

 

[rx-7ames]

So I found out what was keeping the 4x4 from working. I started poking around and found where some wires were missing and messed up under the dash. I guess this is where the wires go from the main wiring harness down under the carpet and to the 4 wheel drive module behind the seat. I saw the green wire was cut and white/purple wire was frayed at the plug. I started cutting open the wiring harness and noticed that the green and white/purple wire were melted together.

I uncovered wire as far as I could under the dash but eventually I couldn't reach anymore and the wires went too far up into the dash. The white/purple wire was still hot too. I wanted to replace all the melted wire and plug everything back up but I don't think I can expose any more wire without pulling out the entire dash or breaking all the brittle plastic plugs. So, I pulled out fuses until the wire was not hot anymore. Does anyone know if the fuse for this wire powers anything else? It looks like my best bet will be to leave this fuse out and convert to a manual shift transfer case.

 

[adsm08]

I would get back as close to the fuse box as you can and just run a new wire.

It's not that hard to do.

 

[rx-7ames]

I traced the wire all the way to the fuse box and ran a new wire to made sure the 4 wheel drive module got power as needed. When I hit the test button it flashed 4 times. The 4 wheel drive still does not engage, plus, I now have no tachometer and volt meter. I'm going to try and fix the wiring the best I can to get my tachometer and voltmeter back. Then I'm going to scrap the electronic transfer case. At this point, not much can talk me into keeping it. It's way to ridiculous in my opinion to justify keeping it.

 

[Click]

I traced the wire all the way to the fuse box and ran a new wire to made sure the 4 wheel drive module got power as needed. When I hit the test button it flashed 4 times. The 4 wheel drive still does not engage, plus, I now have no tachometer and volt meter. I'm going to try and fix the wiring the best I can to get my tachometer and voltmeter back. Then I'm going to scrap the electronic transfer case. At this point, not much can talk me into keeping it. It's way to ridiculous in my opinion to justify keeping it.

I got the four flasher too. Just took the motor off. I have to crawl underneath with Vice grips to put it in 4WD. I got to figure this out