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Lawndart
New Member
Hello. The issue is resolved. I just wanted to post hoping to help someone else with a similar situation and point them in an easier direction. Longish story...
1999 Ranger 2wd, 3.0L, Auto, 180k
-LONG-
About a year ago, I noticed some hard shifts and the speedo bouncing. I did some light research and changed out the stock FoMoCo VSS (on top of the diff) for a Duralast unit. I stopped by Ford, and was informed the VSS was NLA. Initially, this swapped seemed to work. Since my main use for my Ranger is winter driving and occasional hauling in the warm months, it did not see a lot of miles since the swap.
We had snowless autumn, so I did not start driving the Ranger again until recently. The bucking, hard shifts and flaky speedo returned. This time the speedo finally stopped working, ABS light was on, OD light blinked and the computer displayed P0500 code (no VSS signal). I swapped back to my original FoMoCo VSS – no change. I checked the connector on the diff (ok) and started moving forward in the wiring. There are two large connectors underneath the cabin directly below the driver’s seat. I separated the connectors and to check for corrosion. The separation was not pretty. The connectors live on a little plastic shelf attached to the frame which makes them difficult to access. The aging plastic on the connector latches broke away. The insides looked fine. However, I noticed some of the wires had rubbed through their jacketing as the plastic shelf held the connectors tightly against a cabin cross member. Further inspection revealed a couple wires were compromised. I had to cut and splice in new wire sections to remedy. I thought this would be the fix – nope, same problem.
Decided to do a continuity check on the VSS wiring from diff forward. I opened the connectors again and all was fine to the connector. I checked the other side of the connector by inserting a pin into the wires as they exited the connector – all OK. This was frustrating, so I started more online research and found this schematic. Hmmm, a RABS test connector seems to have direct connection to the VSS. Ran some long jumper wires and tested continuity from the diff connector all the way to the RABS test connector. Green/black was good, red/pink did not have continuity – there was a break somewhere. I had already tested to the big connectors underneath and passed them with the pin in the wire trick. The break was between the underneath connector and RABS test connector. I removed the driver’s seat and cut the carpet to expose the wiring – all looked great and there is NOT a connector under the driver’s seat – just a nice grommet pass-through and redirect of the harness to the door sill. Nothing looked appealing for testing. I decided to splice and run a new wire from the red/pink exiting the underneath connector up to the RABS connector and make the connection there to solve the break issue. I tested it first with a jumper. ABS light off, OD light off so it looked promising. I cut the red/pink wire for the splice at the back of the connector, stripped the connector side and then attempted to strip the other side of the wire going into the harness and up through the floor under the driver’s seat. When I pulled on the wire to strip the end, a 2-inch piece of the wire pulled out harness!!! Well, the wire break location was revealed! Why it broke up in the harness is a mystery. I carefully exposed more of the harness to get to the shorter wire and spliced in a new section. All is well and it is very nice to have smooth shifting once again.
-SHORT-
If someone is having a similar issue, the FIRST thing I would do is remove the connector on the diff and (with long wire jumpers) test the continuity of the VSS wiring all the way through to the RABS test connector in the engine bay. If the wires test fine, replace the VSS sensor and test. If continuity fails, start testing from the diff forward and avoid taking the connectors apart if possible (inserting a pin into the wire before and after connectors) for testing.
1999 Ranger 2wd, 3.0L, Auto, 180k
-LONG-
About a year ago, I noticed some hard shifts and the speedo bouncing. I did some light research and changed out the stock FoMoCo VSS (on top of the diff) for a Duralast unit. I stopped by Ford, and was informed the VSS was NLA. Initially, this swapped seemed to work. Since my main use for my Ranger is winter driving and occasional hauling in the warm months, it did not see a lot of miles since the swap.
We had snowless autumn, so I did not start driving the Ranger again until recently. The bucking, hard shifts and flaky speedo returned. This time the speedo finally stopped working, ABS light was on, OD light blinked and the computer displayed P0500 code (no VSS signal). I swapped back to my original FoMoCo VSS – no change. I checked the connector on the diff (ok) and started moving forward in the wiring. There are two large connectors underneath the cabin directly below the driver’s seat. I separated the connectors and to check for corrosion. The separation was not pretty. The connectors live on a little plastic shelf attached to the frame which makes them difficult to access. The aging plastic on the connector latches broke away. The insides looked fine. However, I noticed some of the wires had rubbed through their jacketing as the plastic shelf held the connectors tightly against a cabin cross member. Further inspection revealed a couple wires were compromised. I had to cut and splice in new wire sections to remedy. I thought this would be the fix – nope, same problem.
Decided to do a continuity check on the VSS wiring from diff forward. I opened the connectors again and all was fine to the connector. I checked the other side of the connector by inserting a pin into the wires as they exited the connector – all OK. This was frustrating, so I started more online research and found this schematic. Hmmm, a RABS test connector seems to have direct connection to the VSS. Ran some long jumper wires and tested continuity from the diff connector all the way to the RABS test connector. Green/black was good, red/pink did not have continuity – there was a break somewhere. I had already tested to the big connectors underneath and passed them with the pin in the wire trick. The break was between the underneath connector and RABS test connector. I removed the driver’s seat and cut the carpet to expose the wiring – all looked great and there is NOT a connector under the driver’s seat – just a nice grommet pass-through and redirect of the harness to the door sill. Nothing looked appealing for testing. I decided to splice and run a new wire from the red/pink exiting the underneath connector up to the RABS connector and make the connection there to solve the break issue. I tested it first with a jumper. ABS light off, OD light off so it looked promising. I cut the red/pink wire for the splice at the back of the connector, stripped the connector side and then attempted to strip the other side of the wire going into the harness and up through the floor under the driver’s seat. When I pulled on the wire to strip the end, a 2-inch piece of the wire pulled out harness!!! Well, the wire break location was revealed! Why it broke up in the harness is a mystery. I carefully exposed more of the harness to get to the shorter wire and spliced in a new section. All is well and it is very nice to have smooth shifting once again.
-SHORT-
If someone is having a similar issue, the FIRST thing I would do is remove the connector on the diff and (with long wire jumpers) test the continuity of the VSS wiring all the way through to the RABS test connector in the engine bay. If the wires test fine, replace the VSS sensor and test. If continuity fails, start testing from the diff forward and avoid taking the connectors apart if possible (inserting a pin into the wire before and after connectors) for testing.
