Hi Team,

Been doing a ton of work on the truck getting it ready to tow this Thursday. I did a test pull with my two car trailer loaded to see how the temps would hold. While doing that, I noticed that my ABS light came on, and lost my speedometer for a bit. It would then come to life and go out again. Everything resets when you shut it down, but has came back every time I drive the truck. It will take 15-20 minutes of driving sometimes, and in that time I will loose my speedometer for a bit, then it comes back, then 5 minutes later the ABS light will come on.

Later today I'm going to check all the fuses. (brake lights and everything work). I'm going to take the VSS chip off and clean it. I also believe there is a module on the transmission that I can check too. (been reading every forum thread I can find)

Things that may have impacted this. Had new injectors and chip put in last week. already had a TS chip so I just swapped in Baby Swamps tunes. New turbo pedestal. I also had a transmission line blow on the highway spilling fluid everywhere. not sure if this could have impacted anything. After I picked the truck up it worked fine with no issues.

Brought it home and installed EGT gauge as the one that came with the truck wasn't working. We also installed a brake controller where we tapped into some existing wiring under the dash. Then installed a air compressor in the rear to power my air bags. After that we loaded up the trailer and took a test pull and thats when the problems happened. I know trailer controllers have been known to cause trouble, but mine is currently disconnected with no voltage running to it and still triggering the light. Any other suggestions for me?

 

WOW..Thats sounds exactly what happened to m7 95 e350...Mine came on after install of brake controller..I took it off two years ago and abs light and speedo haven't worked since..I replaced the speedo cluster and rear end vss sensor and nothing..I'm curious if you did the same as me..LMK ill be watching this thread..

 

I'll keep you posted. I changed out the VSS on the rear Dif yesterday with no luck. Trans is now in limp mode overtime the speedo stops working. I brought it to a technician today as I don't have time to work with it before my road trip tomorrow. Hopefully they can get it sorted out.

 

I also noticed my third brake light was out. I remember that being tied into some of these things. Will research it now to see.

 

third light out does weird things, don't use an LED in there

 

For anyone following along it was indeed the pigtail wires that so many talk about. It was pretty bad shape all the way to the fuel tanks. Replaced them and it seems okay.

 

Bill, thanks for reporting back. Can you give more information on the pigtail wires you referenced? Which ones, what locations ...

 

I went to autozone and got the generic VSS senser and the wiring harness for it.

https://shop.advanceautoparts.com/p/...ensor+harness#

I think that is the link. But you may want to just tell them your truck and they should be able to pull it up. The wiring was bad from the connector at the rear pumpkin to the gas tank. Looks like a previous owner put some butt connectors there and water/fluids go inside and eventually ruined the wire. I cut it out and quickly ran some wires with electrical tape to the new VSS and harness. AS light went off and stayed off for the 30 mile test drive. Sadly I didn't have time to get my truck ready to tow my 2 car trailer so I left her home. Plan on doing the wire the right way with heat shrinking when I get back. The only variable is that I have to re hook up the brake controller. I don't think that was what caused the wire to go bad, but you never know. Seemed odd that it all went bad after I installed it. Maybe it was just coincidence.