What factory systems keep working?

Hello everyone. For the sake of conversation, let's assume someone is pulling the 3.0l V6 out of a 2005 Ranger Edge and installing any other engine of their choice. The engine of choice doesn't matter as it will in no way be connected to any of the stock Ranger systems, other than the ignition switch. It could be a carbureted engine or it could be a modern engine with a stand-alone harness.

At this point, what factory systems keep working?

The fuel level gauge is the only gauge in the instrument cluster that I believe will continue to work as normal as the other gauges will have no input signal.

The head lights, brake lights, marker lights, and turn signals should work as normal.

The dome light should work as normal with the switch on the dash as well as with the doors opening/closing.

The horn and radio should work as normal.

The heater system should work as normal, assuming the engine is plumbed into the heater core.

The A/C system is questionable to me. If the wires to the factory A/C compressor were used to turn on the new A/C compressor on the new engine, I believe the A/C system should work as normal, but again, that is questionable to me. Refrigerant compatibility is something to be considered, but not for this question.

I believe the fuel pump would work as normal. When the key is turned on, the fuel pump should run and stay running with the key in the ON position. Fuel pressure compatibility with the new engine is something that needs to be considered, but isn't important for this question. Return line or no return line is also something that needs to be considered, but not for this question.

Power windows, locks, and mirrors should work as normal.

Airbag system should work as normal.

That's all I can think of right now. Anyone notice anything that I have overlooked? I'd appreciate input from anyone that wants to offer any suggestions or confirmation of my assumptions. Thanks!

Welcome to TRS


In 2004 and up, Rangers got the HEC instrument cluster, because of Fords dismal record of odometer tampering, lol

Anyway the HEC is "married" to the PCM(computer), so vehicle won't function with either removed, just a heads up

The gauges that don't need the computer are temp, oil, fuel and voltage
Tach and speedometer/odometer wouldn't work, but could be wired to work

If you left the PCM in place, and hi-jacked the speed and tach wires

And used an engine/transmission combo that either didn't need a computer or used a separate computer.

You would just have the CEL(check engine light) to deal with

As long as the HEC, PCM, SJB(body computer), and other modules(i.e. ABS, restraint, ect...) were left intact everything would still work fine

Ford speedo/odo needs 8,000PPM signal, you can use the rear ABS sensor, like Ford did in 1998-2000, with an interface module to do that.
Tach is just a tach signal

2005 instrument cluster below
Oops its posted in another thread, here: https://therangerstation.com/forums/showthread.php?t=167158

You can have a look, there are only 3 connections(on 3.0l) from HEC to PCM: tach, speed, and low fuel monitor
There are also "data lines" between HEC, PCM, SJB and the other modules
Google: CAN Bus system

Yes, the AC system activation does pass thru PCM, but it would work normally if you used an ECT sensor on new engine and hooked it up to PCM.
Or you can bypass PCM entirely as far as AC system goes, by adding a relay, that's all the PCM does, acts as a relay to turn off compressor if engine is too hot, or line pressures are too low or too high.

Wow, that's a lot of info. Thanks for that! I'm going to take this in small steps

If I were to remove the engine and the engine wiring harness, and remove the ECM from its place on the firewall, but leave everything else. What systems would work?

To be honest, the only things I'm interested in working are the climate controls. If the heater and A/C work, I'm good with that. I have a full set of AutoMeter gauges that I'm planning to use, so the instrument cluster doesn't matter. I don't care about the antilock brakes and was seriously considering removing the ABS manifold anyway.

Why would you want to pull out the PCM(ECU), it doesn't take up much room and is not in the way?

Engine wiring is fine to pull out, ID the oil pressure and temp wires then cut the others

If PCM goes then instrument cluster goes, whole thing

And not sure how the Body Computer(SJB) will react without PCM and HEC, may be fine but don't know
SJB controls all the cab electrics, lights, wipers, door locks, power windows, ect..........

I would sell the 2005 as is and get a 2003 or older Ranger

I'd rather not sell the truck, but I understand what you mean. I've got a '97 Explorer that I'm making into a stand-alone harness for the 5.0. Need to remove the Ranger PCM so the 5.0 PCM can go in it's place. My thought process was if the body acts normal without the 3.0 and PCM, all would be good. Again, not worried about the instrument cluster. I know there's a lot of issues with the newer Rangers and a 5.0 swap. I'd just really like to keep my truck and make it work.

PCM is not all that big, it just needs 12v and good grounds to work so put the 5.0l PCM somewhere else in engine bay and leave stock PCM as is
You can use the 5.0l PCM hook up for CEL

You will need to add a fuel line to the 2005, 1997 Explorer ran a two fuel line system, IN line from pump and filter and a Return to gas tank line from fuel pressure regulator on the engine.

And probably best to add that relay for the AC to by pass the 2005 PCM since you need the ECT sensor for the 5.0l PCM

Personally, I think it would probably be far more time and effort efficient to just throw the Explorer's dash and harnesses into the 05.

Take the whole system, lock, stock and barrel. There are some minor wiring differences, but dealing with those is much less work than reinventing the wheel.

Plan #1 was to swap everything from the Explorer into the Ranger, but the Explorer is a Limited, which has the automatic climate controls (which is having issues), factory air ride system (which is having issues), and the digital info center in the center console (which is also having issues). Haha! The good thing about the Explorer is that it has only 124,000 miles. I just don't want all the "fancy stuff" in my Ranger from the Explorer.

I know about the fuel lines, but thanks for mentioning it.

I've been searching for a '96 or '97 Explorer with the manual climate controls so I can use it's wiring, dash, etc., but haven't had any luck in my area.

I can find '03 and older Rangers with blown engines or trannys fairly cheap, so I can use everything from one of those. I've seen a lot of info online about 5.0 swaps into '03 and older, but haven't found any specific information. I see where people say "you can take some wires from this plug and put it into this other plug", but I haven't seen any specific instructions. I was hoping to put together a very specific build thread with my truck and detail every little step.

Well, got lucky today. Someone posted up a '97 Mountaineer with the 5.0 and everything else I was like looking for on Marketplace this morning. I was able to contact them first and it was close to where I was working, so went to look at it. Scored it for $700.

I had the intention of using the 5.0 I already have, but it looks like more trouble than it's worth to keep the truck as it is. Now I can use the Exploder, Mountaineer, and the Ranger to make one vehicle.

Thanks for everyone's input. Much appreciated!