DTR #9 to ground..
Sent the connector view..

Hayapower, I received the plug view and description. Thank you. I replaced the trs twice with new units from autozone to rule out the new sensor being bad. They were happy to return both units if it didn’t fix the problem. I originally replaced it due to the p0705 code after the rebuild. #14 blew with both new units plugged in, but not with them unplugged. I now have the original trs installed back on the truck.

10 4
If need be I can send you all the complete Pinpoint Tests for 705.
Being the cross over/unit harnesses were unplugged would take the lead frame etc off the diagnostic plate. Since the DTR is a switching/reduction sending unit and doesn’t apply a ground, other than the other power inputs, and sig returns, hard to believe it’s shorting. If shorted to the v/sig ret. I’d think the PCM would be a smoking brick.. Testing the #9-ground with a connector disconnect, must yield an open.. Could remove the #9 pin from the connector, reinstall and the fuse should then hold if the cause is related. Ignition On, probe in Park, then Neutral,
Could also pop the trans cable off and put it in an optional gear/s then go Key On,, Hold, or pop?

Hayapower, I just got home. I’m going to plug in the trs, put battery cables on, put gear shift in other positions than P, and then insert the fuse. I will post the results in about 20 min. I may need the 705 tests, but first I am going to try this and do some head scratching. Thanks again.

Ok. I started by testing the battery. It read 12.00 about 40%, this battery is dated 1/18 and is about a year old. I have been testing the electrics and such, but it should be much higher than that. Anyway I put a battery out of my other f150 in it.

Battery: 12.70 Pins 1, 7, and 8 are not used.

Pin 2: 0.00 signal return
Pin 3: 5.05 TR3A
Pin 4: 11.97 TR1
Pin 5: 12.20 TR2
Pin 6: 11.97 TR4
Pin 9: 12.20 Voltage supplied in start and run. Fuse protected, 14
Pin 10: 0.00 Voltage supplied in start. Fuse protected, 14
Pin 11: 0.00 Trailer tow relay, reversing lamp control
Pin 12: 0.00 Power hot in start with park or neutral

Now for the shifter positions. I put the truck in each position with the key in the on position, then inserted the fuse in the #14 slot.

Park: Fuse blows
Reverse: Fuse holds
Neutral: Fuse holds
​​​​​​​Drive: Fuse blows
2: Fuse blows
​​​​​​​1: Fuse holds

I have to go eat and Christmas shop with the wife now. I am going to think over what this data means while I’m out, and I will monitor the posts if anyone has an idea. Thanks

Ok. I started by testing the battery. It read 12.00 about 40%, this battery is dated 1/18 and is about a year old. I have been testing the electrics and such, but it should be much higher than that. Anyway I put a battery out of my other f150 in it.

Battery: 12.70 Pins 1, 7, and 8 are not used.

Pin 2: 0.00 signal return
Pin 3: 5.05 TR3A
Pin 4: 11.97 TR1
Pin 5: 12.20 TR2
Pin 6: 11.97 TR4
Pin 9: 12.20 Voltage supplied in start and run. Fuse protected, 14
Pin 10: 0.00 Voltage supplied in start. Fuse protected, 14
Pin 11: 0.00 Trailer tow relay, reversing lamp control
Pin 12: 0.00 Power hot in start with park or neutral

Now for the shifter positions. I put the truck in each position with the key in the on position, then inserted the fuse in the #14 slot.

Park: Fuse blows
Reverse: Fuse holds
Neutral: Fuse holds
​​​​​​​Drive: Fuse blows
2: Fuse blows
​​​​​​​1: Fuse holds

I have to go eat and Christmas shop with the wife now. I am going to think over what this data means while I’m out, and I will monitor the posts if anyone has an idea. Thanks

Odd that P fails, and N doesn’t.
Pinouts matched the connector view placements, color tracers? Being the trans was baked, new to you, makes wonder if an issue was present prior to your build..

I’ll send you the pinpoint tests, tests for 705 start at Test C. Not sure it will be of much help, but may help with a short to ground/power if it exists.

Thanks hayapower. The fuse blowing issue was not present prior to the rebuild. The abs and brake light comes on when 14 blows, and they were never on prior. I’m missing something, but I will find it. I am going to analyze everything in the morning. Have a good night, and thanks again. The schematics have been a big help.

-Chris

Good morning hanky,
The transmission code on the door is a B. This indicates it is a 4r75e. I should have checked. I think the only difference is the addition of another speed sensor and different ring gear on the E. The readings should be the same. If I am wrong please let me know. Good call on checking the code.



I don’t have the published readings, but I checked the ones on my plug multiple times. I don’t think the plug wires are in the wrong spots. I drove the truck about 100 miles home when I bought it, and it never blew the 14 fuse. If the fuse would have blown it would have set the abs and brake light and I would have noticed it. The forward clutch, frictions and steels were the only ones burnt. The others looked really good. I checked the drum really well for cracks etc.. I know it lost OD because of the eclip that broke on the servo, and I figure the broken piece got into the valve body causing the burnt frictions. If it was something electronic that caused the burnt clutch, and is now shorted, it should not blow 14 when All the plugs are removed from the trans.

Update: Ok, so in the middle of writing this post I decided to put the truck in R and put in the fuse to verify I had backup lights. To my surprise the fuse blew as I was inserting it. So I turned the key off, inserted a fuse and turned it back on. It blew 14 instantly. So I ran the shift test again and here are the results now.

1st test last night. 2ed test this morning

Park Blew. Blew
Reverse. Held. Blew
Neutral. Held. Held
Drive. Blew. Held
2. Blew. Held for 30 sec then blew, tried again blew instantly
1. Held. . Held

I’m not sure what’s going on here. In looking at the dtr plug diagram, it seems that the only wire protected by fuse 14 is pin 9 the reverse circuit, but it’s not powered past the trs plug until the lever is in reverse. The trs is good, and the plug would seem to be good since it doesn’t blow 14 while unplugged. Is there any way pin 9 could be shorting but only while plugged in and the trs still be good? Or maybe something is shorting the trs when it’s plugged in, and I blew the 2 new trs units when I plugged them into the harness resulting in the same symptoms. Opinions?

I thought you guys might like to see what we’re working on here.