So I've got this 3.9L (wiring question)

[64rovr]

And I want to put it in the Series... rather, put the Series body on the RRC chassis and engine/tranny. But in demolishing the donor vehicle I am completely and totally bewildered by what wiring I need to be able to reuse the EFI setup and **cruise control** and the Range Rover steering column control unit (major unit that mounts behind the steering wheel that the stalks come off of).

The factory wiring is a mess... its all in very good shape just a birds nest from the factory. I haven't cut anything out of it yet aside from things I know I dont need- center console loom, seats, etc.

Please help me. Please? :D

[SUE ROVR]

Leave everything intact.

I mean it, everything, then once it is running in the new chassis start eliminating things if you want/need (accessories, lights which make up a lot of the wires etc).

Does it have an alarm? What year is it? Get the manual and start figuring out what does what. But put it in the new chassis and make it run first. At least that is the way I would do it. Best to leave the ignition and ECU wiring intact as it is, too much room to screw it up.

I would rather cut the dash apart than cut the wires. Also if you do disconnect anything LABEL IT. Take white paper and legibly write what it is, where it goes and what it connects to. The use clear packing tape to afix it to the wire on both end of the connection.

Ron

[DieLucas!]

Adam,

it may be a good idea to pull the dash, heater core, A/C, and front interior so you can have a good look at the wire loom.

Ron's right that you may want to leave as much intact as possible. You'll need to at least disconnect the engine loom from the ECU/main harness (you'll have to pull the body eventually).

Your best bet is to start disconnecting stuff...keep cutting to a minimum. Start with peripheral wiring like the rear lamps and signals and try to source the wiring all the way back up to the firewall...lable what braches of the loom go where. Ultimately, you want to end up with the loom completely free of the body laying on your garage floor with tags telling you every location it goes.

BTW, if you completely screw up the ECU wiring, let me know. I'll tell you what goes where :D

[LRover]

If it is a late '80s or early '90s Classic leave the EFI wiring harness connected to the engine and follow the main harness into the passengerside area. It's possible to remove the EFI wiring completely from the body without cutting anything...unplug the ECU from the harness so it will fit thru the firewall. The cruise control is another matter.

Mike

[64rovr]

Originally posted by LRover
If it is a late '80s or early '90s Classic leave the EFI wiring harness connected to the engine and follow the main harness into the passengerside area. It's possible to remove the EFI wiring completely from the body without cutting anything...unplug the ECU from the harness so it will fit thru the firewall. The cruise control is another matter.

Mike

This is helpful... I would definetly be willing to get rid of cruise control if it would be easier to remove the rest of the harness. Right now all that is left to the interior is the lower dash assembly (just the part that the AC condenser is housed in) and the AC system. the rest of the interior of the truck is stripped, and the bodyshell is cut apart. all that remains of the body is from the hood down and the floor from where the back of the front seats would be.

Basically, what I need to know is what is the easiest way to remove the entire EFI harness intact- if you say that it can be done through the firewall then that is a major help.

Do any of the wiring components under the driver's side of the dash pertain to EFI? There must be 25 relays and control assemblies under there- alost none of them labeled. If all that I need to worry about saving is the main loom going from the ECU through the firewall then that isn't that big of a deal.

Thanks!

[Serious One]

Hey Adam,

I've only seen the entire harness removed from two trucks. One was when DieLucas! bought my EFI setup and cut the harness at the bulkhead, and the other one I don't know how he got the harness out. I dunno if it was intact.

Something a tad easier might be to convert it to a carb or TBI and you can get a cruise control from VDO if you really wanted to have that.

As you have found out there is a mess of wires you'll have to struggle through to get it to work right.

Not an easy project, I cringed when DieLucas! told me what he wanted to do.

[64rovr]

I'm considering the TBI route... one of the main things driving me to do this swap is ending up with EFI in the end. I know you have the ProJection set up- what I was thinking of was using an Edelbrock or Offenhauser 4bbl intake and then adapting the TBI system from a 4.3L V6 to work? It is another option that I am considering for sure, and it would most likely result in a more workable setup in the end.

Does anybody know what sensors a TBI system needs? I would obviously like to avoid anything that needs a crank sensor and such like that... keep it as simple as possible.

Originally posted by Serious One
Hey Adam,

I've only seen the entire harness removed from two trucks. One was when DieLucas! bought my EFI setup and cut the harness at the bulkhead, and the other one I don't know how he got the harness out. I dunno if it was intact.

Something a tad easier might be to convert it to a carb or TBI and you can get a cruise control from VDO if you really wanted to have that.

As you have found out there is a mess of wires you'll have to struggle through to get it to work right.

Not an easy project, I cringed when DieLucas! told me what he wanted to do.

[Serious One]

I have the Pro-Jection as you mentioned and the only sensor it needs is one 02 sensor after the junction of the exhaust.

Pretty simple as far as that is concerned.

Howell makes one of the best fuel injection systems around, many rock-crawling guys use it and are very happy with it. I dunno if they make one for Buick/Rover.

Howell used to be the EFI guy for GM till he got fed up and started his own company FYI...

[64rovr]

Ideally, both for economical reasons and servicing reasons, I would like to use all factory GM parts if I decide to go this route. I would love to have the Howell setup, but would love even more to do it with cheaper more readily available parts, first.

I will stop by my friend's shop today (major GM guru) and see what he knows about the TBI setups and what he thinks about adapting it to a different engine.

[64rovr]

okay, just checking Howell's site, they offer a "universal" V8 TBI kit for $1200, that includes everything needed. Not a bad price, and it may be an option once I get a few paychecks under my belt. But, I am still very interested in doing this with junkyard parts- it would suit my style better :D

[Serious One]

Nothng wrong with junkyard parts!

You should have heard my son last week. He's starting to understand how we built the CrewCab and he says to me, "Dad, that things just one big rolling junkyard".

I almost cried.

*sniff*

Keep us updated.

[DieLucas!]

Keep in mind I only cut the harness free because I was not using the rest of the main loom. I did not, however, cut the engine loom. I just cut connectors off of the main loom that were needed to plug into the engine loom.

Yes the engine loom will disconnect 100%.

Not to chastise you for wanting to go with TBI, but why? TBI is an over-glorified carburettor. If you are looking for simplicity, why not get a Carter and carb the engine? I just don't see the point of ditching a solid port-FI system for TBI. If it is due to not wanting to mess with any of the RRC loom whatsoever, it's easy enough to just use the engine harness and ECU. It would be the same amount, or less, work than trying to wire in a TBI set-up.


BTW, Mike, it took me about three hours to install your EFI on my truck...that's the time from prepping the intake gasket and mounting the manifold and intake, to routing the wiring, splicing in my hot and ignition leads, and starting the truck :D

[Serious One]

Originally posted by DieLucas!
BTW, Mike, it took me about three hours to install your EFI on my truck...that's the time from prepping the intake gasket and mounting the manifold and intake, to routing the wiring, splicing in my hot and ignition leads, and starting the truck :D

Now I definitely know I didn't charge you enough. :flipoff2:

[DieLucas!]

Originally posted by Serious One


Now I definitely know I didn't charge you enough. :flipoff2:

You can have it back if you want...I know there are a few things in your garage worth bartering :D

[64rovr]

DieLucas- can you tell me where the exact loom I need goes? As I said, I would love to keep the Rover EFI system but the wiring has me scared :D If its as easy as you make it sound, then that is the way I will go, for sure.

The loom in the passenger compartment- is all I need to save the main harness that goes to the ECU? Or do I need any of the under-dash wiring as well?

[DieLucas!]

Originally posted by 64rovr
DieLucas- can you tell me where the exact loom I need goes? As I said, I would love to keep the Rover EFI system but the wiring has me scared :D If its as easy as you make it sound, then that is the way I will go, for sure.

The loom in the passenger compartment- is all I need to save the main harness that goes to the ECU? Or do I need any of the under-dash wiring as well?

You will need to have the dash removed and the A/C unit pulled so you can get to the loom at the firewall. Removing the engine harness is simple (from the main loom...you'd like to leave it intact on the engine). Remove the huge connector on the ecu under the passenger seat, remove the relays from the mounts under the seat, then disconnect a white rectangular connector on the inside of the firewall, and disconnect a black round connector on the outside (engine bay) of the firewall. This should be enough to free the engine harness from the main loom.
BTW, there are a few wires that run from the engine/ECU loom up under the dash...those are for the check engine and service engine lights; not important if you do not plan on saving any of the main loom.


Now you need to ask yourself what you want to do. Do you want to keep the main loom and incorporate stuff like the cruise-control, turn-signal and windshield wiper switches? Then keep the loom. If you want to reduce the total amount of incorporation and just splice the ECU into the wiring within your Series body, then scrap the rest of the wiring (except for the wiring from the black-round plug that then runs under the body...the VSS and tranny sensors run into that; you'll want those circuits for the ECU).

Personally, I do not think it will be that hard to incorporate the entire RRC loom into your Series. But you'll need to remove it intact. This is not hard, but only after you've removed the entire dash, heater, and AC. It also is not hard to just splice the ECU into your Series loom.

[64rovr]

As part of this project I'm going to completely rewire the entire vehicle anyways, so saving the main loom isnt that important as I will be making my own to suit later on.

I still want to be absolutely sure though, that all I need for wiring is the loom that goes to the ECU?

[DieLucas!]

Originally posted by 64rovr

I still want to be absolutely sure though, that all I need for wiring is the loom that goes to the ECU?

Yes.

So again, look for the white rectangular connector and black round connector. Don't cut up any wiring from the black connector; save it on both sides (the ECU side and the engine bay side). On the white connector, cut the wires on the non-ECU side about 4 or 5 inches down so you have enough wiring to splice later.

It may also be easier to remove the plastic shrouding surrounding the engine loom inside the cab (as it leads under the passenger seat). This way you can locate and remove the relay/circuit for the check-engine light and service engine light. Agai, those circuits will hit the firewall and head towards the driver's dash.

I'll try to send you a few pics of the two connectors you are looking for tonight.

[pendy]

This post drives me nuts. How many times does FIAT have to tell you it can be done. This is a piece of cake compared to some of the other projects you have shown us here. Quit asking questions until you go look at the harness on the engine and how it routes through the firewall and to the computer. Then pull it out and report back to us. Here are some items you will have to splice in.

ignition +
fuel pump
check engine light
speed sensor(you will have to make a speedo cable with this signal generator or live with the check engine light)
transmission neutral/drive sensor just ground to trick the ECU that it is alwas in gear


Does the RRC have an owners manual in it. If it does then that has your wiring diagram. What year is it and I will help you figure out your wiring when you are ready to fire up the engine. Just lay the harness on the engine and start pulling the body off.

Jim Pendleton

[DieLucas!]

Originally posted by pendy

ignition +
fuel pump
check engine light
speed sensor(you will have to make a speedo cable with this signal generator or live with the check engine light)
transmission neutral/drive sensor just ground to trick the ECU that it is alwas in gear


Adam,

you can scrap the check engine light. However, you can mount the diagnostic display box somewhere visible to alert you when a code has been triggerred (mine sits by my gear selector). The transmission drive sensor circuit should stay intact (it and the VSS circuit should be in that round black connector).

As far as the speed sensor goes, you'll find on the '90 (right?) that there is no cable going up to the spedometer. The nice thing is the VSS of that year is designed to allow a cable to connect to the other end and drive a spedometer ala pre-'90 RRs. Find a cable in a junk yard or give Marty at British Pacific a call (he spent 20 minutes with me rounding up different cables in the warehouse, comparing the sizes of the drive ends).

If you botch the fuel-pump, no big deal. Run it off a relay from the same lead as the coil (might as well put the coil on a relay while you're at it).

And finally, the nice thing about the Rover ECU is the A/C circuit. The ECU gets a signal when the A/C is on so it can adjust for the added load. I don't know if you plan on incorporating your A/C, but if not, you can wire this circuit into the on-board air relay if you plan on going that route.

What Jim said...just go do it.