Re wire

[Carrier6]

This might be a dumb question but here goes.
I have a 1994 E450 4 window short bus. I am getting tired of fixing wires in the bus side. Has anyone just pulled everything out and started over? I don't want anything from the bus build side, just the van/Ford side. I can get a new wiring harness for a standard 1994 E450 for around $800 and just replace it. Could also just buy same year and motor scrap van and pull the harness. Has anyone done this, or have any reasons why it wouldn't work?

Thanks Ray

 

[AlphaHare]

Here's what's happening on the E450 2008 version with Thomas coachwork.

My Thomas is getting it's primary bus functionality from the trailer harness connections. That's right, from the back of the bus, not the chassis interface connector in the driver side pillar that comes with a cutaway chassis. Go figure. That's the signals and power for running, brake, turn, and reverse (backup).

Except for the marker lights, clearance, and running lights (excluding the van body ones) everything is wired directly meaning it works if I turn off the power to the relay circuit boards over the drivers compartment. Only the amber lights go through the circuit board - there are a lot of those lights and they're distributed through relay connections.

There two circuit boards over the drivers compartment control all the 'bus' stuff. That's the flashers, the stop sign, maybe a front crossing bar, dome lights, the internal AC and heating, and whatever options you may or may not have.

Here's how you can test: The two circuit boards are powered by a large cable that runs to the engine compartment and controlled by a 60A breaker. Turn it off, run the bus and see if your lights (and everything else) are still working.

The net result is I'm going to pull the circuit boards out and wire directly to my lights. I'll use a smaller relay board and terminal blocks for distribution and reclaim all that space. For now, I'm also keeping the existing wiring to the lights themselves and haven't decided if it's worth redoing. I've put in LEDs, so the power is significantly reduced.

 

[cadillackid]

the harnesses were seaprate from the factory.. the cutaway chassis was built by ford then sent to whatever the coach builder was.. theres typically a body-builder connector where the coach builder connects so they can have functions like rear lights and there are usually a couple interconnects available to such as a starter interlock for a door open etc..
the bus switch panel for school lights and such is separate... ford vans were optioned with controls on the ford dash available for rear heater and A/C thats part of the ford harness.. you can just take the switches out and again unplug the body builder connector then run your own wires from that connector for your rear lights and such that you need..


the biggest bus part tied to the ford was the A/C and rear heat.. rear heat delete is just a matter of removing the T's from the lines or looping them..

there are severasl threads here about removing the rear A/C on a van bus and converting to van-style components to keep the dashboard heat and A/C functional like a regular van..



but I would start by finding the body builder bulkhead connector thats your tie from the van harness to the bus side.. you can recreate what is necessary from there..

 

[nikitis]

I would say if you're having issues with the bus body section behind you, and it's multiple of those items , it's likely where the internconnect from the chassis and the body connect. I've gone over my 1995 bus wiring, and there's about 3-4 of such harness connections on mine so everyone elses should be similar. I would even try to unplug them in the panel and then re-insert and see if the issue doesn't go away as a test.

You may have to use a multi-meter on each line and stick a probe into the connector on both sides to ensure there's continuity.

 

[Rucker]

What problems have you been encountering? Depending on what you're experiencing there may be easier ways...

I have a '99 E450 with the 6.8 V10 and I'm kinda a Ford guy. I also have an F10 and am in the middle of an engine/trans swap for that, which is in large part the same plant with less cylinders...so here's some observations.

The engine wiring harness cannot be removed easily without pulling the engine, so if you want a real challenge try to pull the harness off one of those plastic stays with little to no room for your hands or any tools. On my F150, I could easily pull the whole harness out after the engine came out.

I also looked at those $800 replacements, but the only issues I had were COP and Fuel injector terminal stay tabs (what hold the connector onto the injector and COP), so I bought a set of replacement pigtails for each and am swapping those only. It's going to be wicked easy to do on the bench. That's why I'm curious what your current issues are, maybe there's a solution less drastic that pulling that harness out.

The Transmission harness is even harder to pull without dropping the unit.

I'm also ohming out every wire just to make sure there are no frays or other issues.

And I had field mice up in the crotch of the V10 and they chewed through the knock sensor wire; I just bolted a new sensor to the back of the cylinder head (not optimal, but works), and if I ever need to pull the intake manifold I'll relocate it to the original position.

 

[Carrier6]

The problems I'm having is that the PO had mice and squirrels get into it. So there are chewed up wires here and there. The compartment where they all are is just a mess. My daughter drives this all over the place and I just want to clean it up and be done with it. Instead of every few months I'm fixing another wire or chasing down something else. I just figured since we don't use any of it why not just get rid of it. Next time she comes by I'm going to look for the service body connection and unplug it to see if it still starts and runs.
Maybe it's just that easy.

Thanks

 

[cadillackid]

The problems I'm having is that the PO had mice and squirrels get into it. So there are chewed up wires here and there. The compartment where they all are is just a mess. My daughter drives this all over the place and I just want to clean it up and be done with it. Instead of every few months I'm fixing another wire or chasing down something else. I just figured since we don't use any of it why not just get rid of it. Next time she comes by I'm going to look for the service body connection and unplug it to see if it still starts and runs.
Maybe it's just that easy.

Thanks

youll still have to hook up the rear lights.. the body builder connector is how the rear lights get powered since the lights are part of the body..


a new wiring harness wont keep the critters out.. thats something unfortunately everyone living in the country seems to face.. I used to store my classic cars at my parents place in their niuce pole building and had to put deterrents and tape over the air intakes for the engine and the A/C to keep the mice away... even the barn cats didnt get em all..