SOLVED: Shift module only sending 5 volts to switch?

[ecgreen]

Hey guys,

Still troubleshooting my electronic tansfer case. I went through the diagnostics in the Tech section (thank you whoever wrote that!). I passed all tests except the last one. It seems that my module is only sending 5 volts to the switch. The diag sheet says it should read 12 volts when you backprobe the module and turn the key on and press the 4x4 button. I am only getting 5 volts. Is this a thing or did I do something wrong? I am also not getting any voltage on the orange wire on the shift motor side of the transfer case connection. I am thinking a bad shift module. Thoughts? Hope I was clear enough.

 

[ecgreen]

Swapped in a new unit and no luck. Gonna go wire the motor to a switch.

 

[Shran]

I would bet money that your shift motor is bad. I have run into this several times now and same deal... 5 volts, no shift. New shift motor fixed it both times. I suspect that there is some sort of resistance issue in the motor itself, hence the low voltage.

 

[ecgreen]

I would bet money that your shift motor is bad. I have run into this several times now and same deal... 5 volts, no shift. New shift motor fixed it both times. I suspect that there is some sort of resistance issue in the motor itself, hence the low voltage.

Interesting, thanks for the post.
Did you have lights at the switch? I do not.

 

[bobbywalter]

light at switch can burn out.


make sure the grounds at the cowl on both sides are good too. quick check is to jumper right from them to bat ground to see if that helps. though usually if that is the issue the oil psi is reading erratic as well.

 

[ecgreen]

I put power to the switch, as per the directions in the tech article, and the lights work.

 

[bobbywalter]

Did you ground the cowl ground directly.?.

 

[Shran]

Interesting, thanks for the post.
Did you have lights at the switch? I do not.

Dash lights yes, indicator lights, kinda. There was part of the process that backprobed the lights themselves, they did light up there, but never if I just pushed the button. After replacing the shift motors, they worked as they should.

 

[ecgreen]

I think Shran is probably right. Even so, I am going to attempt to wire the motor to a momentary switch and bypass everything else. It is certainly the cheaper of the options. I will do a nice write-up if I succeed. If I don't I'll put in a new motor and post to this thread as a follow-up

 

[lvwill]

I know this is a long shot, but it happened to me. The p.o. of my ranger obviously did a trans swap at some point and after I got the truck it wouldn't shift into 4-low. Went through everything and finally found out that it had the wrong neutral safety switch. In it. The electric transfer case needs a 5 pin switch and the manual needs only 4

 

[ecgreen]

Well, whoever said the motor was shot wins the prize. I went to wire up a switch today and I tested the motor with 12 volts and all I got was a buzz. So its either seized up, or fried.

I ran the yellow and orange wires from the motor to 12v. Just to check, that's what I should do to get the motor to turn right? Correct me if I'm wrong...help the FNG

 

[ecgreen]

New motor works, but the wiring harness did not come with the brown and green wires that go directly into the transfer case. Without these I will not be able to get into 4-low. I can't for the life of me figure how to get the pins out of the old connector. Is there a way or should I cut the wires from the harness and solder them directly to the wires going into the case?

 

[ecgreen]

I ended up hard-wiring it. Wires were too brittle to remove anyhow. The casing (what is the plastic layer called on the outside of a wire???) on the brown wire coming out of the case was/is very brittle. It looks like you need to open the case to replace it. Not interested at this junction. So, I cut back as much bad wire as I could and wrapped it in electrical tape. Eventually when/if this fails, I will wire the motor directly to a momentary switch. For now, it works flawlessly.

So the moral of this thread is that Shan was correct! If you get 5 volts and not 12 to the switch from the control module, your motor is bad.