Back-up light switch

[gliderman8]

Hello everyone... a couple of months ago my '97 Explorer lost its turn signals and dash lights. I found that the common ground wire that feeds both circuits was faulty so I just ran a new ground to the blinker and dash dimmer and everything works.
Now, I find I have NO BACK-UP lights... I would like to check the back-up light switch but don't know where to look for it.
Can someone guide me in the right direction?
Thanks for any assistance!!

 

[dogfriend]

The backup switch is part of the transmission range sensor.

I'm assuming auto trans, but if it is a manual transmission, I believe the backup switch is also mounted somewhere on the transmission.

 

[gliderman8]

Thanks dogfriend.... the diagram will certainly help and it is appreciated!
Dumb question: What is DTR referring to on the diagram?

 

[dogfriend]

Digital Transmission Range sensor. There are two types - I don't know which transmissions use which one.

For the purposes of troubleshooting the backup light, it doesn't matter if it is a DTR or non DTR, you are looking for 12v on the black wire w/ pink stripe (BK/PK) when in R.

 

[gliderman8]

Thanks again df. I will begin my search tomorrow and see if I can locate the backup switch and test for some voltages. Stay tuned!

 

[gliderman8]

Dogfriend... From looking at the schematic you supplied it appears that both the backup switch AND the Transmission Range Sensor have to be working.
Do you know where the Transmission Range Sensor is physically located? If the BU switch is good, then maybe I can switch the sensor. Thanks for letting me know. By the way, I have a 5.0L V8 1997 Explorer.

 

[dogfriend]

For an automatic transmission, the transmission range sensor is the backup switch. The switch is built into the device.

Your V8 Explorer will have a 4R70W transmission. I believe that it has a DTR because the manual has the procedure to adjust the DTR for the 4R70W. The DTR is located on the left (drivers) side of the transmission. It has the shift cable attached to it and an electrical connector.

Here is a sketch from the service manual:

 

[grizzard]

DTR problem??

Digital Transmission Range sensor. There are two types - I don't know which transmissions use which one.

For the purposes of troubleshooting the backup light, it doesn't matter if it is a DTR or non DTR, you are looking for 12v on the black wire w/ pink stripe (BK/PK) when in R.

Dogfriend,, i have a dtr on my 93 ranger this thread may help me with my problem if could take a listen' A COUPLE DAYS my ranger would not shift out of first gear (auto) then it would not start in park, shifted to neutral and started, then it was stuck in second gear, stoped to check fluid was perfect color and level was good, no burnt smells. Then it would not start in park or neutral had to jump across the solinoid to start. Could these problems be from a bad dtr?? thanks for your advise..

grizzard

 

[gliderman8]

Hello Dogfriend-
I had an interesting day. My backup lights are now working as they should.
This is what I found.....
There are three square (approx. 3" sq.) wire connector plugs that sit just behind the main power distribution box that has many relays and fuses in the engine compartment on the drivers side. I noticed the wire bundle on the top connector had about five wires cut, and some were touching each other. I removed the main power box, then soldered in short lengths of wire to join each of the cut wires. Everything is now working. How did the wires get cut?
Really, this is the mystery since I don't think they can rub on anything to cut them. I am really at a loss on this one. I'm just glad the backup lights now work and I can get my state inspection done.
THANK YOU for all your help.... it is MOST APPRECIATED!!!!
gliderman8

 

[dogfriend]

Dogfriend,, i have a dtr on my 93 ranger this thread may help me with my problem if could take a listen' A COUPLE DAYS my ranger would not shift out of first gear (auto) then it would not start in park, shifted to neutral and started, then it was stuck in second gear, stoped to check fluid was perfect color and level was good, no burnt smells. Then it would not start in park or neutral had to jump across the solinoid to start. Could these problems be from a bad dtr?? thanks for your advise..

grizzard

I think the 93 Ranger/Explorer is different because it has the A4LD which is a different trans. I don't have a manual or schematic for 93, but I would check the transmission range sensor and the cable that connects it to the shift lever.