12 volts DC
 

The voltage input into both sets of contacts should be a nominal 12 VDC as that is the supply voltage at the respective fuses. The amps for the ABS module circuit should be very low compared to the tail light circuit. That is also the reason for the 5 amps vs 15 amps fuse size difference.

The ABS circuit is a signal circuit so to speak whereas the tail light conductors carry the amps to illuminate the bulbs.

Since pushing the HDC button resulted in nothing happening, I regard that as good as that means nothing got worse.

When you say "pulling the F66 fuse resulted in no improvements or complications", I am unclear as to what the means. My perception was that with the brake pedal pushed and F66 still in the circuit that the air compressor would at least get you to normal height and that D and R would function? The problems started when you removed your foot from the brake.

The reason for pulling the F66 fuse was to hopefully fool the 3 or at least the ABS portion into thinking the brakes were on and that the air system would not drop; also that the vehicle could move forward and backward without the air system dropping.

I assume that is what you mean by HI and LO functions worked without issue and yes, the 3 did go forward and backward without the air system dropping?

I guess if you could summarize what is happening, or not, when the F66 fuse in both in circuit, and pulled, that would be helpful for us.

To me, it sounded like maybe the situation improved with the F66 pulled, but I am unclear, hence the request for the summary.

Hi and Low range - got it.
 

I reread what you were saying and I decided HI and LO refer to the transfer case and that both High and Low range can be selected and all seems good.

Also since the Terrain special programs Knob seems to be working, that suggests to me that both the transfer case and transmission are OK including the tranny computer.

What I am not clear is if your 3 will pump up to normal height when in Neutral and then deflate or what happens.

If it did pump up but then deflate, I was hoping that by pulling the F66 fuse, the system would not deflate when the brake pedal was released and the 3 put into gear.

If it does, that suggests the 3 is going into what I call safe mode. A bad wheel alignment problem or malfunctioning steering wheel location sensor can do that as well as air system wiring problems, and other stuff.

Anyway, the summary is needed by me for certain.

With the key on, foot off the brake, can you shift out of Park(try it with the engine not running so you don't accidentally hit something behind you)

There are 2 circuits for the brake switch, and one can be fine with the other failed, one controls the lights and the other the shifter(along with many other functions, but these are the easily noticeable ones) There have also been several issues with corrosion in the harness causing issues like this.

bbyer:
With the fuse in, pedal depressed and started we get: BOTH the drive height and off road height indicators illuminated. When the lever is pressed down, there is no change. When it is pressed up, the ACTUAL height goes from access to off road and ONLY that indicator is illuminated. Any further change not possible after that. Once the brake pedal is released, all warnings come back and suspension is lowered to access height.

With the fuse out, pedal depressed and 3 started we get: all warnings immediately, just as though the pedal was never depressed with the fuse in. suspension stays at access height.

Yes, HI and LOW are functioning.

Roverguy7:
YES, with the key on and no pedal, you can shift out of park. WTF? How is this possible??

Also worth mentioning:
realized my lower control arm bushings are shot.

had a trailer harness hooked up months ago at uhaul. never had a problem till recently, but went ahead and disconnected to eliminate issue. could crimps in the tail light wiring be causing voltage issues??

Thanks all!!

The shift interlock is controlled by the TCM(valve body) based on CAN input from the ABS about the second switch inside the brake switch. This switch is normally closed, and when pedal is depressed, voltage is removed. If you are not getting proper power to that side of the switch, the ABS doesn't know that the pedal is ever not depressed, which is the problem. The fault is a correlation fault between the two switches in the brake switch, so turning the vehicle on with the pedal depressed, the lamp control portion of the switch shows depressed, as does the ABS input, as soon as it is released, the lamp side shows released, but the ABS side still shows depressed.

There is a splice in the RH door sill that I have seen cause issues with this before, as well as a connector(C1165L - located in LH lower A-pillar area) You will be looking for a Red wire, and possible corrosion in the splice/connector.

Roverguy7 is on to the problem I think.
 

I am impressed. I never thought about the shift interlink working or not working.

I assume the splice referred to is one of those "telephone" squeeze spice devices that holds water instead of repelling it. When both key fobs suddenly stop working and the door locks do not function, it is often a splice down in the door sill wiring bundle that has corroded and quit transferring signals. It sounds like something similar re the interlock.

I also forgot that F66P powers not only the ABS side of the brake switch but also the Hill Decent Switch (HDC), the Steering Angle Sensor and the DSC, the anti skid circuit.

That is why things got real bad when F66P was pulled. I was thinking just the ABS module would lose brake light signal.

Regarding the trailer harness hookup, I could see it causing problems as in most USA systems, the filament for the signal light is also the filament for the brake light.

In our 3 and most Euro systems, the Brake light bulbs are different from the Signal light bulbs; that is the filaments are not shared. I assume when the hookup was removed that the remaining conductors are not showing any significant degree of damage?

For your 3, in the two rear assemblies, you should have a total of two Brake light filaments, (plus the LED high mount illuminated); four tail light filaments, two Signal light filaments, two Backup light filaments and two Rear Fog bright Red filaments when the rotary headlight switch is pulled out to the second click.

Holy good fix Batman!!!!!
 

Words alone can not express my joy right now, but I'll give it a shot. To bbyer and roverguy7 both, I would like to extend my greatest thanks for your assistance!! In the end, 7 hit the nail on the head with the wire splice underneath the passenger front sill. As soon as I pulled it up, I found moisture!! I found a splice for a smaller gauge red wire near the front, just before the harness starts up the firewall, with one wire to the rear and two to the front. Covered in blue tape, the connection blew apart as soon as I started to unwrap it. This can't be how LR put their cars together, is it?? Anywho, a simple patch and WAAALA!!, all the faults magically disappeared and all is right with the world. I am indebted to 7 and this forum, as I would never have found this on my own. I thank all for their help and will continue to check in here going forward. Now, on to the lower control arm replacement!!

Roverguy7 had it figured.
 

I am impressed as well. Roverguy7 had it figured.

You are also to be complemented at your persistence - not complaining, just searching and searching - it can be very depressing.

The fix is so typical Land Rover - it costs nothing, but is near impossible to find.

To figure it out, you have to be persistent, patient, and I think smart. With these electrical problems, you have to have the whole wiring system memorized and then be able to correlate the symptoms with how the system might react.

After reading your and roverguy7's posts, I spent some time looking at the splice drawings. The best I can determine is that it was splice SJ105 that Roverguy7 referred to and which you found.

If I read the drawings correctly, there were perhaps four red conductors coming together, all being what are called 0.5D gauge which I think is metric for thin, about AWG 20 or 22. Does that seem about right?

Again, well done.

Replacing the A arms will be a relief after this - you can bang, saw, twist, and hammer all you like. When you are finished, there will be nice new shiny black parts to look at and show off.

What I wonder is does any other vehicle manufacturer do this sort of thing? Somehow I cannot imagine GM or Ford dealing with a bunch of loose wire ends, I assume right on the assembly line - it sure looks that way and it seems there are splices like this all throughout the 3.

Glad you got it sorted.

Yeah, these splices are not the best, and later models(+08) went to actual heat shrink. That said, a lot of manufacturers do use similar types of insulation for the splice(the splice itself is fine, it's the lack of sealing the bare wires that causes issues)

In design, the LR3 was supposed to be pretty water tight, and if that had stayed true through practice, these splices would have never been an issue.

Before I go
 

Thanks again Dave. Before I wrap this one up, I would like to pose two questions to you and bbyer both? I will be entertaining new tires and maybe mufflers in the near future. I'd like a slightly larger, more aggressive tire, but one that doesn't lend itself to a great deal of road noise. My mufflers are fine, but I'd like something with a little more of a throaty note, without being "loud".

My first question is, what may be some good options for tires, without breaking the bank, and is any size larger than OEM an option? I would be keeping my factory 18" rims.

My second question is, does anyone have any recommendations on some good mufflers that they've used themselves?

Cheers and thanks!