Low range shifting issues

[Slog58]

My issue is I can't get my pickup to shift while using low range. Pickup is 91 F350 auto. If I put it in drive it won't shift to second, if I put shifter in 2 it'll go to second gear but won't lock torque converter or ever shift to 3rd. Any ideas on what to look for or check for?

Thanks!

 

[Black dawg]

Low range light come on? Trans module needs to know if t case is in low.

 

[Slog58]

No, no 4x4 light comes on either. The connector on the transfer case looks good and tight. Any way to ohm that out or check for voltage on those pins?

 

[Slog58]

Anybody have any tips or tricks??

 

[Jake_IN]

Any way to ohm that out or check for voltage on those pins?

Do you have a test light or a multimeter?

 

[Slog58]

Do you have a test light or a multimeter?

Yessir

 

[Jake_IN]

Then I would crawl under there and pop the connector off and start poking it and seeing if any of the wires have power. You could also shift it into 4hi and 4lo and see if the switches on the transfer case are switching.

Probably will need to have the key on for this.

Disclaimer: I haven't looked at a wiring diagram to see how the wiring is setup for this.

 

[catbird7]

Could there possibly be a fuse for this?