After looking at diagram 13-10 as shown above, a zoom-in diagram of 20-1 (post # 61), I mistakenly asked Hamboned1 to check on fuse 3 and 34, the correct fuse to check is Fuse 7 (10A) as shown in red arrow above and black arrow below.



let's label this Fuse Junction Panel as C235 and C225.
12V signal from START of ignition switch into pin 34 of C235 thru Fuse 7 (10A) and exit C225 from pin 3.

1) Forget checking everything at C235 just check that 10A at fuse 7 with ohmmeter less than 2ohm ok
2) Blue arrow above, unplug range sensor, voltmeter red to pin 10 (BN/PK) harness side, voltmeter black to chassis ground, turn key to START, you should get battery voltage at Pre-range sensor.
3) For Post-range sensor, plug the harness back into range sensor, voltmeter red to pin 12 (carefully insert into the pin and don't break the wire jacket, make sure it has contact to the terminal inside pin 12, if not the result is going to be misleading with 0V), voltmeter black to chassis ground, set to PARK gear, turn key to START and you should expect to get the same battery voltage as Pre-range sensor.
If all 3 are good above, your TN/RD wire to terminal 86 has a break(s), you need to use ohmmeter and do resistance check, higher resistance, closer to the break. I think the break most likely underneath the relay box near to terminal 86, perhaps due to multiple tests. Worst case you can just replace that TN/RD with another fresh new wire and crimp it into terminal 86 (female side).

 

Ok im back at this Taurus issue again been out of town and busy, I have not gave up yet, lol!
#1 I checked fuse #7 fuse is good and getting less than 2 ohms!
#2 only getting 0.54 V at pin#10 (BN/PK) wire with range sensor unplugged to ground wire chassis with key on to start!
#3 getting 0 V at pin #12 (TN/RD) wire to ground with key on to start!
I also replaced ignition switch under steering wheel and still nothing!

 

Hamboned,

If you know anything about wiring, if only one strand is not broken, resistance reading is not reliable, will read continuity, BUT will not carry enough current to operate anything.

You can obtain better results much easier using a test light. The illumination of the light will tell you if you have power,a good connection or bad connection or no power at all.
You cannot always use a test light because certain computer components will not tolerate a test lights draw.
The situation we have today is EASILY checked with a test light.
2 things you always do, after you connect your test light to a good ground , you touch any positive power source and verify the test light works.
The next thing you do is start from the power source to the circuit under test. This is when a wiring diagram comes in.

The most difficult thing is finding the components location so you can verify power is present or not. It is that simple.
You do need to know when power is supposed to be there, ie when turning the key to the start position.
That simple test light will work both ways, if the clip is clipped to a ground and the probe is touched to a source of power OR the clip is clipped to the source of power and the pointed probe is touching a ground.
The simple way to verify if power is getting to the starter solenoid is to clip the test light to the small terminal (S) on the starter solenoid, stick the test light up by the windshield where you can see it , making sure the point is making a good connection with the sheet metal of your vehicle and turning the key to the start position.
If the test light lights, power is getting there.You can do this alone and know right away where you stand.
It takes longer to type all this than to actually perform the test.

By the way,,,,,, I hope you replaced the ign sw assy that is located under the dash,mounted on the steering column, next to the brake pedal.

 

ok not getting any power at S terminal on starter when I turn switch to on and start position using a test light and yes i replaced ignition switch under dash mounted on steering wheel column

 

The reverse ordering to test your test light:
1) S terminal -> failed
2) Terminal 86 of the starter relay (remove the relay first then clamp the alligator from your test light to a needle probe pin, small enough so you can insert into where terminal 86 goes)
3) Terminal 12 at your range sensor
4) terminal 10 at your range sensor

Same procedure how you tested the S terminal with your test light only on START position, not ON/RUN. If your test light still doesn't light up on 2 to 4 above, then the break is between the fuse box and your ignition switch.

 

Test #1, #2, #3, and #4 all failed. no light on test light on all 4 Test

 

If you are not getting any 12v to your range sensor, you need to check the fuses, I don't remember which ones to check perhaps you do. You can also go over the ignition switch tests and let us know.

 

Also refer to post #101, check fuse 7. Remove the fuse and check continuity, while it's removed use voltmeter black to metal housing of your steering column to get ground, red to fuse 7 left-hand side (also check right-hand side just in case), you need to get 12v when you turn the key to START position. You are testing from ignition switch's RD/LB wire to fuse 7 directly at the fuse slot.
Assuming the left of the slot is connected to pin 34 of your fuse junction panel connector (which you don't want to get to for now), then right side of the slot is pin 3 and is connected to your range sensor. Test at the fuse 7 slot first which is easier to get to.

 

Here's the summary of the flow going backward starting from S terminal:
1) S terminal of your starter solenoid -> failed
2) Terminal 86 of the starter relay (remove the relay first then clamp the alligator from your test light to a needle probe pin, small enough so you can insert into where terminal 86 goes) -> failed
3) Terminal 12 at your range sensor (12v inbound from terminal 10 of your range sensor, 12v outbound to terminal 86 of your starter relay) -> failed
4) Terminal 10 at your range sensor (12v inbound from pin 3 of your fuse junction panel C225) -> failed
5) Pin 3 of your C225 (12v outbound to terminal 10 of your range sensor, 12v inbound from right-hand side of fuse 7 slot at C225)
6) Fuse 7 slot right-hand side (12v outbound from left hand side, so pin 3 has a wire that's connected to right-hand side fuse 7 slot)
7) Fuse 7 slot left-hand side (12v inbound from pin 34 of your C225, so pin 34 has a wire that's connected to left-hand side fuse 7 slot)
8) Pin 34 of your C225 (12v outbound from STA terminal of your ignition switch)
9) Ignition switch mechnical + continuity test result -> ?

At step 6 and 7, you can check continuity at rest on right-hand side of fuse 7 slot to pin 3 of C225 and left-hand side to pin 34. Remove the fuse at fuse 7 slot, you should expect to get 12v on pin 34 as well as the left-hand side when you turn your key to START.
If there is a break on this two wires find out where the break is and fix it. Right now I'm assuming the left-hand side of fuse 7 slot connects to pin 34, if it's not, please switch the left and right.