Hey guys. well we just picked up a 1999 f350 7.3 cc lb srw 6 speed manual 2wd truck and the reverse lights don't do anything... (had some other things wrong too but I have figured them out on my own)

So the bulbs in the back checked out good on both sides...


I crawled under the truck and on the transmission there is an electrical plug towards the upper rear part of the transmission on the passenger side that has nothing plugged into it. The weird thing is there was no harness dangling anywhere under the truck that would have plugged into this?

1. Can someone confirm that this electrical connector on the ZF 560 2wd is the reverse switch. (located in the rear upper corner on the passenger side)
2. where does the "missing" harness go that connects to this port on the trans? I will gladly tap into something under the dash and make my own switch... if needed...
3. Does anyone have a whole truck wiring diagram? for future reference...

I will try to snap some photos tonight.







ALSO there are 2 connectors throughout the truck that have nothing plugged in...
first is right behind the front driver wheel well splash guard basically under the clutch pedal on the exterior of the cab.( looks to be 2 wires) what does this go to? maybe ABS? ( I don't have any abs lights so maybe an option I didn't get?)


the second is under the dash on the knee bar on the driver side. it has a Christmas tree on it for mounting but not mounted anywhere. somewhere said this might be the Aux idle control module? what is this for and do I need it for a diesel?













Things I have already tackled.

• aluminum foil upgrade for door lock poppers. (All 4 doors)
• rekeyed doors and ignition
• rear window lock
• 3rd brake light repair
• headlight brighten and bulb replace
• full interior cleaning (using totally awesome) Previous owner was a smoker...
• Sound deadening in floor, doors, and rear panel,
• dome light switches in door latches cleaned and replaced
• e brake cable repair
• hood shocks replaced (learned the hard way)
• new clock spring in steering wheel for airbag, horn, and cruise.

Thanks


Stephen

 

bump... anyone have any idea what this connector is?




If I wire up a replacement here is my thoughts...


tap a keyed+ fused source (maybe tap original fuse for reverse if it has one). run this to switch on transmission. run other wire from switch to rear harness for reverse. and trailer reverse

 

Do you have 2 batteries?
If the connections on a secondary battery are dirty, or the battery is bad, it may cause this. At least, it does for trailer wiring issues.

 

I will look into this and report... any way to check the batteries beside going to autoparts store?

 

If your in need of the wiring diagram go to BBB Industries- Premium Alternators, Starters, Power Steering Products and go to and mouse over to technical information, from there select the drop down menu and select TSB & wiring diagram database ( you will have to register for a free account) then it is matter of putting in the info for your truck make, year, model, style, engine and then you should be able to find what your looking for.

Hope that helps.

 

Unless you own a load tester it is way quicker, but you can check them at home. Here is a video on how to do that.