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I have a 2004 f350 with a 6.0 diesel that I purchased used 6 months ago. From the start the tow/haul light in the dash would not come on, when I push the switch the truck goes into tow/haul mode and works fine but no light. I have checked the switch and the wires from it as far as I can and found no wiring problems. I have also checked the bulb its fine. I have no idea what to check next. One thing I did notice is that their are two wires coming from the switch and they go to a male/female connector, and the female connector has three wire leading from it, is this normal or do I have the wrong switch in the shifter? I am all out of ideas.
I think the tow/haul light was either on the end of the shifter or in the dash, but not both. Perhaps you got a model where it was at the end of the shifter but someone replaced the shifter with a different model.
I have a manual so I couldn't really say for sure, though.
I guess I should clarify, the on/off button is on the shifter but the tow/haul light is in the lower right hand corner of the instrument cluster. Some trucks have both the light and button on the shifter and others are like my truck.
I know the on/off button is on the shifter. On some trim levels, so was the tow/haul light.
Put the instrument cluster in test mode. Hold the trip/reset button while turning the key to ON. Once in test mode release the button. Then press the button until all of the cluster lights come on and see if your tow/haul light does also.
I'm assuming that your truck was designed to have the tow/haul light in the shifter, but someone replaced the shifter to one without the light. How long have you owned the truck?
Yes I did test the instrument cluster, all lights came on including the tow/haul light on the instrument cluster. As far as the shifter goes I have seen both types, ones with the tow/haul light on the shifter and the ones with the tow/haul light on the dash. I am going to try to determine if any changes if any were made to either the cluster or shifter via the previous owner. If it turns out everything is stock, what else would cause this malfunction?
According to the electrical diagrams that third pin in the connector is grounded by the PCM to turn on a tow/haul light in the shifter. But there is no wire going to the instrument cluster that is for a tow/haul light.
I would assume then, that if your stock truck had the tow haul light in the shifter, then the PCM was programmed to control that light. If it had the tow/haul light in the cluster, then the PCM was programmed to send a command across the SCP data bus to order the instrument cluster to turn on the light.
It would seem to me that the only real possibilities are 1) the shifter was changed at some point, or 2) either the programming in the PCM or cluster has been altered or somehow failed at some point. I find #2 highly unlikely.
Thanks your help is very much appreciated, I will do some further investigating re the shifter and see where it leads me, but its sounding more amd more likley that the shifter has been changed out.
Well I checked with two local dealerships who both said that the I have the proper tow/haul switch on my shifter lever as per my vin number. I am wondering if anyone has a wiring schematic for the tow/haul switch circuit for my 2004 f350 diesel, it appears I will need to dig a little deeper into the problem. Thanks
The leftmost circuit in this diagram is the entirety of the tow/haul switch/light wiring. It is a simple push button signal to the PCM with a light controlled by the PCM.
I would think it would be nearly impossible. When the truck was built, the PCM was programmed based on the build sheet. The build sheet would have determined what program it got as well as what shifter it got. Later, if a dealer tech hooked your truck up to the computer with Fords software, it should have looked up the VIN number and retrieved the same build sheet from the database and then loaded the latest version of the right software for the truck.
Now, I could see where it's possible someone using a programmer might've somehow managed to dump the wrong PCM program in. I don't know much about custom programming but I suppose it's possible for the programmer to make an error that might cause such a thing. You could take it to the dealer and have it flashed with the latest software. Explain the problem to them and have them flash the HEC (instrument cluster) also. If it was program related that should fix it.
The leftmost circuit in this diagram is the entirety of the tow/haul switch/light wiring. It is a simple push button signal to the PCM with a light controlled by the PCM.
I know this is an old post, but could someone confirm if the tow mode schematic for this '04 F 350 would be the same for my '03 6.0 Excursion? My tow mode indicator light is on the end of my shift lever, I would like to know the color of the wire that provides current to illuminate the light on the end of the shifter...