Will not start and keeps blowing # 20 (prnd21) fuse when shifting out of park

[SunlitComet]

not necessarily and if it was broke it would either not unlock when ignition power is off or would lock if the ignition was off. The key out lock of course locks everything. I don't see the part itself capable of an effect on what is going on at this time.


This is if things if things are normal:

Description and Operation When the Brake Transmission Shift Interlock (BTSI) is energized, the Solenoid locks the Shift Lever mechanism in "PARK". When not energized, the BTSI Solenoid returns to the unlocked position.

The Components involved in the BTSI Circuit are as follows:

• Park/Neutral Position Switch
• TCC/Stop Lamp Switch
• BTSI Solenoid

Fuse #16 (Turn/Back-Up) supplies B+ (12V), after the Ignition Switch, to the BTSI Solenoid via the Park/Neutral Position (PNP) Switch and the TCC/Stop Lamp Switch. With the key in the "RUN" or "START" position, the Shifter in "PARK", and the Brake Pedal released, the Solenoid is energized. This locks the Shift Lever in "PARK".

Important:

• Note the BTSI portion of the TCC/Stoplamp Switch (Pins C & D) is CLOSED with the Brakes released. Depressing the Brake Pedal OPENS the Switch causing the Solenoid to de-energize, unlocking the Shift Lever. The BTSI portion of the PNP Switch (Pins B & C) is closed in "PARK" only. The Circuit is not active with the key "OFF".

Because you can start the vehicle by bypassing the large wiring harness going thru the bulkhead and it is affecting the shift indicator going thru the sam haness for about a foot or two I think you will need to address that. I will post the bulkhead pin-out below for you to sort thru for starters.

BTW the harness tape will get your fingers sticky.


Harness Connector
C100

Notes

C100

Pinout Description
C100

Notes

C100 (Part 1 Of 2)

Notes

 

[William Mosley]

What is the shiny box with two sets of wires going to it? Behind the dash or in the dash so to say. Its next to the steering column. Looks likemsome kind of module or computer or something.

2nd Question: if my truck was driven with the main transmission wiring harness and part of the nuetral position switch wiring harness ripped out of the truck, from the 4wd driveshaft, would this short something out in my trans? Or something else in the truck?

Could this be my problem?

Found out the mechanic did not properly secure wiring harness before test drive after install of trans. And ripped them out.

 

[SunlitComet]

if it has yellow connectors that would be the airbag computer. other wise it would be the transfer case control module.

Uh, yeah. definitely a possibility.

Put another harness in and retest.

 

[William Mosley]

If I put in a new wiring harness, how do I tell which wire goes to what?
There are several wires that are the same color and size.
I think this is what is wrong now, i think there are wires put back together wrong.
How would I go about narrowing down what wire is wrong?

Could something electrical have gone bad inside the trans. From running it without all the wires hooked up to the trans? Or wires that might have touched together.

---------- Post added at 02:14 AM ---------- Previous post was at 02:09 AM ----------

What do you mean a possibility, the metal box or the truck driven with some of the wires ripped out.

---------- Post added at 02:16 AM ---------- Previous post was at 02:14 AM ----------

Oh, by the way a really appreciate all the help you have given me thus far.

 

[SunlitComet]

Possible it can short something. But mostly likely just a plain wire that may be grounded. Generally if wires in the tranny are not connected certain functions will just not operate. But you get codes for those as well. If a solenoid say got triggered from power getting to it when it should not have it would just sorta like activate it function. How the tranny reacts is dependent on what the tranny was doing at the time and what function was triggered.

Give me the connection end points of the wires you want to identify and I could come up with diagram and connectors views.

 

[William Mosley]

The wiring harness was replaced from back of the transfer case including the o2sensers all the way to the back of the motor. Including the main trans. Harness asmwell as the neutral position switch on the side of the trans. A color coded diagram would be nice.

Mabe one or two of the wires was put together backwards or in the wrong spot all together. I mentioned before there are several wires the same color and the same size.

I tried swapping around the same color wires but with no success.

I got the dash almost completely out now. It's 102 degrees now everyday now and with no shop or shade work is kinda slow. Plus it's my birthday today so I work on it some more tomm.

Btw thx for your help you really seem to know your trucks.

 

[SunlitComet]

The diagrams won't be color coded in color if that is what you mean. They will be like others I posted. The do have the wire color printed on them along with the circuit number and gauge along side each wire. Is that okay?



Mine is Wednesday.

 

[William Mosley]

Isn't being a Leo great

---------- Post added at 12:06 AM ---------- Previous post was at 12:05 AM ----------

Those diagrams will be fine.

 

[SunlitComet]

Transmission and Drivetrain

Notes

Light Duty Transmission/ Heavy Duty Transmission

---------- Post added at 11:51 AM ---------- Previous post was at 11:50 AM ----------

VCM Power and VSS
Transmission Controls

Notes

VCM Power And VSS

---------- Post added at 11:51 AM ---------- Previous post was at 11:51 AM ----------

Brake Switch and Solenoids
Transmission Controls

Notes

Brake Switch And Solenoids

---------- Post added at 11:52 AM ---------- Previous post was at 11:51 AM ----------

TFP Valve Position and PC Solenoid Valve
Transmission Controls

Notes

TFP Valve Position Switch And PC Solenoid Valve

---------- Post added at 11:54 AM ---------- Previous post was at 11:52 AM ----------

there is a quick starter let me know what others you may want. BTW you have the light duty tranny(4l60e).

 

[William Mosley]

Ok, I traced one of the two Pink wires coming from the #20 fuse. The pink wire going to the instrument cluster is fine. Any idea where the second pink wire goes so far it goes somewhere under the truck to the trans?