Hi all,

I am new to this forum. I see a lot of good information, and did a fairly extensive search on things related to my issue. While I got some good ideas, I would like to pick your brains for some more. (rather long)

I have an RV built on a 99 E450 chassis with the V10 engine. While in storage at an outside facility for a few months this fall I had some rodents chew through the main engine/sensor harness as well as the O2 sensor wiring and some of the vaccuum tubes. All the damage appears to be contained to the rear end of the Vee under the dog-house.

I have since replaced the damaged components (at least all that I can find that are damaged). After completing the work the engine would still not crank. After some searching, I found out that I am not getting power to the red/light blue wire at the starter relay (solenoid?) on the passenger side fender well when the key is in the "start" position. If we put 12v to that pin on the relay the engine will start and run fine, which means that the relay is functioning properly.

Further investigation and consultation of my Haynes manual has shown the following:

- White/Pink wire under steering column does have power with key in start position

- All fuses check out okay.

- No power (key in start position) to red / light blue wire coming from main chassis harness prior to connection with previously damaged engine/transmission sensor harness that I replaced

-with engine running overdrive "off" light on shift lever flashes continuously no matter what position gear lever is in. while driving everything functions properly including the OD off button

What all of this suggests to me is that there is something still wrong with the neutral position switch either in the column or at the trans. I believe that I have eliminated the transmission from the equation as everything appears to function properly there. However, after spending a few hours inventing new Yoga positions trying to get under the dash board and find the switch/connection that changes the signal from the white/pink wire to the red/light blue wire, I have not made much progress.

Does anyone have thoughts or suggestions on where to find such a thing and/or how to proceed from here?

Thanks in advance for your assistance.

 

The Wire color changes at the Transmission Range Sensor on the Transmission.

 

Subford,


Thanks for the response. I was pretty sure, and I checked last night to confirm, there is no white/pink wire going back to the sensor on the transmission. The closest I could find was a tan/pink that I guess could be a dirty wht/pk but it doesn't look like it. Either way, that wire does not seem to have power at any point (key on / start). Is it possible that there is something in a different location?

My manual shows a slightly different schematic to what you had (though mine being from haynes, I'd be more inclined to believe yours), it shows an input from the PCM through a Light Blue/Yellow wire. I do have that wire heading back toward the trans, and it has 5v at key on, no change in start position.

The only wire in the group heading to the trans that seems to be effected by the key in the start position is a white/purple that goes from 12v @ key on to 0v at start.

 

I don't think you should be worried about any computer inputs if the above diagram is the correct one. This is the line that powers the starter relay directly. The anti-theft gizmo(if you have one) and the transmission switch look like the only components between the keyswitch and the starter relay.

Maybe you can work from the other direction. Find the red/lightblue wire coming out of the transmission switch. Unplug the transmission switch, jam a scrap piece of wire up in the plug at the red/lightblue terminal, and if you are on the right track, when you touch that to the battery +, it should crank over.