Wiring Woes

[printjunky]

Walked out to the Rover after work thinking: OK, dash is all reassembled on the bench, just hafta bring it out of the shop, hook up some wires, get the front-end harness connected. Should be done by dark. Everything working by Sunday.

Until I was reminded that the PO stopped the renovation at around the 80% mark. Harness in, mostly not hooked up. And the harness varies a bit, of course, from all of the wiring diagrams I've seen. Most of it jibes with the manual (and after reading some of the wiring horror stories, I count myself lucky that it's 75%-80% right on), but there were a few mysteries. 2 flashers, one on the correct colored wires, to the turn stalk, but on the other end, connected to the ignition switch instead of the fuse box as in the diagram. The other hanging from a brown wire. The fuse box wiring setup, while it looks like it would work fine - correct power in - power out arrangements, not exactly as prescribed. Also, an odd in-line-fused brown wire with orange tracer, that looks original (apparent same period/construction as the harness, typical vinyl sheath, runs into the main harness), but I haven't found the engine bay side of it yet to try and figure out what it might have been. It was attached to the ignition switch, so perhaps a PO added accessory.

I understand the harnesses and hookups were intended for multiple permutations. So some of this might just be vestigial MOD/FFR/LWB variants, etc, leftovers.

I have a few specific questions:

Behind the dash, and on the passenger side of the engine bay, there are 2 sub harnesses (pictured). The dash one, has a connector that appears to have nothing to connect to. And the engine bay one, has the connector half filled with (correct colored) wires to the rear lights, but the other half of the connector is empty. Does anyone know what these go to, if anything?

Oh, and I have 2 large brown wires on the fuse box. One I know and have traced back to the solenoid/ignition switch. The other is a mystery, so far. Though I haven't tried to track it yet. Any ideas? Same gauge as the ignition wire (don't think it's the test lamp sockets). And there is an extra wire coming off the wiper motor that's not on the schematic. Blue/Green Trace.

The fuse that's not used (SIII 88" Petrol) I assume is for some variant. No reason I can't use it, I assume? (looks like that's what the PO did)

One more thing. The ignition switch:
1=power in
2=start
3=start (what's the difference?)
4=keyed on/accessory

I'll probably have more questions/requests for confirmation of my suspicions, but thanks for any input.

Shawn

[siii8873]

for the ignition switch the positions are

1-power in
2- run power, energized in run position
3-start
4- not used, not sure

Is the connector that's connected to nothing the hazzard switch? I can't see the wire colors well enough to tell.
As far as the rear harness it looks like just enough wires for the rear lights. What are the colors on both sides of that connector?

[kevkon]

One of the "sub harness" is for a 4 way hazzard flasher as is the second flasher. The mating part of the hazzard harness goes to the switch.

[siiirhd88]

The fused brown with orange trace wire on my 88 was for the heater blower. The extra blue with green trace wire on the wiper motor should be for the second speed on the two speed motor.

Bob

[amcordo]

I *THINK* I have the original key ignition system (it's a lucas #something). In which case here's the overview:

Key has three positions:
A: Off
B: Run
C: Ignite (starter)

With that in mind, wiring is as follows:

1. Power supply (from battery)
2. Acc output - On with key at B and C positions.
3. Ignite (to starter) - On with key at C position.
4. ACC output (safe) - On with key at B position, but off with key at A or C positions.

I've attached a relay to both position 2 and 4 that power the various devices that I only want to work when the vehicle is on.

Output 4 is actually super useful. If you've got any somewhat modern devices (Radio) that you don't want to constantly have power, wire them through this instead of Output 2. That will avoid powering them during the time period you're most likely to see under/over-voltage (during crank). Likewise, if you have any devices that draw any significant power (maybe your windshield wipers, or a defroster, etc) you'll want them on Output 4 so that they're unpowered during ignition and more power is available for your starter.

NOTE: I am remembering those numbers from the top of my head. Just know that that is the four functions. To figure out which is which for sure, use a little test light with aligator clips and turn the switch to the different settings. That's how I figured it all out.

[Jim-ME]

One of the many things that I learned from a great Rover shop south of me is the value of an audible continuity tester. I've now got one that is a built function of my multi-meter and it's wonderful. It will permit you to see where wires start and end.
Jim

[printjunky]

Thanks for the replies guys.

Can anyone confirm that the engine bay sub-harness plug (over by the air filter on a LHD - probably hard to see with filter installed) in fact, has those 4 connections left unused in a petrol 88? (Siii8873 - Yes, the wires that are used (that 5-pin connector on the left in the photo) have been confirmed as the correct colors for the rear lights.)

Does anyone have any insight into how accurately the wiring diagram represents their hookups to the fuse block? As I said, mine varies a bit, with a heavy gauge brown wire going to each side of the normally unused (pos. 3-4) fuse. I know one is coming in from the solenoid. Haven't tracked down the other yet.

Also, anyone know what's behind (and to what effect) the two legs of the fuse box (pos. 5-7) being connected.

http://www.roversnorth.com/store/ima.../LR-page84.pdf (http://www.roversnorth.com/forums/../store/images/category/medium/LR-page84.pdf)

Kevkon - That makes perfect sense on the inside sub-harness. Didn't catch it because the hazard harness is sitting just out of sight on the passenger floor waiting for the center dash to get reinstalled. At least the picture of me staring at this connector (probably for minutes) with a quizzical look on my face is amusing.

Bob - that wire does go over toward the heater, but the heater has the 2 (correct, I believe) wires going to it that trace back to the dash (G/U & G/ ... something - not at home to check). I do have an auxiliary heater mounted in the passenger footwell, maybe it was intended for that, I'll have to check it out.If so, I'll just wire it up to the heater high switch.

Tony - that's as I suspected, though I was not getting current to #2, in B key position, which seemed odd. I'll retest in case of a fault in my switch after work, but I'm certain you're correct. I did catch the usefulness of #4, with zero current at C key position, for, as you say, radios, etc.

Jim - Been coveting a better DMM for awhile. Mine doesn't have an audible. My plan after work is to make up a test light with leads long enough to run out to either end of the car. I'll have a confirmation of continuity (a couple of the dash ends of the wires have been insulation-worn, and needed shrink-wrapped), and I'll be able to ID and map everything.

I'm considering making up a visual, specific map to augment the factory wiring diagram (eg: this wire runs into this bundle, and comes out through this grommet to this connection). Might help the next guy. (similar to these (on this amazingly detailed site, you're probably all familiar with http://tiny.cc/qa68f ), but for non-MOD models).

[Terrys]

The first picture is the plug from the multifunction (horn, etc) stalk on the right side of the steering wheel. The second is the 10 pin plug on the harness (right hand side of engine bay, back) where the rear harness (6 pins) run. The remaining four pins go to a mating plug with White, Green, White/redish brown tracer, and Brown with yellow tracer. I forget what all these go to (I'm more of a 2A person, though I have a couple s3s too) Since white with a red tracer is the solenoid engage wire, I'll make a guess thats what that one is.
There is an S3 schematic on the RN series electrical parts page.

[printjunky]

Wait, I'll bet those other 4 pins are for the rear fog lights! Of course. Shoulda thought of that. Can anyone confirm?

[Les Parker]

Rear fog lights should have:-

Red/brown
Red

Plus black for the Earth.

[4flattires]

Prior to the big fire up (battery cable hookup)....

I would hook one circuit at a time and even consider an initial hookup with a 12v lantern battery and avoid sending major amps downstream during your virgin run. Sounds like your relying on PO work as well as your own on a not-quite-the-same color coded and wired harness.

Just sayin....

[Les Parker]

Good idea to use low amps. I use a battery charger on the 2 amp. setting, just to check all the circuits are good. Its enough to power up the lamps and flasher relay but keeps the smoke in the harness.

[Terrys]

Can anyone confirm that the engine bay sub-harness plug (over by the air filter on a LHD - probably hard to see with filter installed) in fact, has those 4 connections left unused in a petrol 88? (Siii8873 - Yes, the wires that are used (that 5-pin connector on the left in the photo) have been confirmed as the correct colors for the rear lights.)
No, It is deffinately used.
Here's the S3 wiring schematic.
http://www.roversnorth.com/store/images/category/medium/LR-page84.pdf

The brown with yellow tracer is the charge indicator wire from the alternator, another is for the oil pressure switch to dash light. Can't remember the other two, and it's to hot to walk out and look at the parts truck, but I can say this, There are two plugs going into the 10 pin one, on each of three S3s I've looked at. (all petrol)

[printjunky]

Interesting. Terrys post implies that I am missing a harness part. I'll have to check around. Came with a ton of spares, including most or all of a spare harness.

Terrys is correct about the brown/yellow wire going to that connector.

The other 3 wires are:
White/Yellow
Green/Blue
White/Red

The only circuit on the schematic that has brown/yellow, as Terrys said, is the charging circuit (I have a GM alt, which is not hooked to anything, that I haven't addressed at all yet). So I'm going to take this to be the wire from the charge light to the alternator.

((Contrary to that being the only Brown/Yellow circuit though, SiiiRHD does confirm a fused Brown/Yellow going to his heater. Seems unlikely we both have stray or PO-added, identical wires. (SiiiRHD - can you tell me specifically where that wire goes? What it hooks to? I think I have the 2 correct (LGY, LGN) wires for hi/lo fan speed. Perhaps as I mentioned, this was meant for the aux. heater.))

As to the other wires on the engine bay harness:

My Haynes shows the White/Yellow to be cold start/choke. (differs from the RN schematic)

Green/Blue is gonna be water temp.

White/Red - the only one I see anywhere is ingnition sw.->solenoid (which is in place and intact - so that's not it. I'll have to double check the color.

[siiirhd88]

The brown with orange trace wire with the in-line fuse is what went to my heater fan. It is not brown with yellow.... My 88 was a Brit spec RHD.

Bob

[printjunky]

Bob, thanks. Brown/orange was what I meant. Starting to get a little confusing!

[printjunky]

OK, now every wire has been labeled, tested a second time, some mouse chew spots have been fixed, and I added the necessary foot of wire to the fuel tank sending unit. (The spade of which broke off immediately upon attempted connection, grrr!)

The good news is that my previous estimate of PO wiring accuracy was low. This thing is 100% accurate, except now for the extension I had to put on the fuel sender wire (yellow was all I had that was a similar gauge). I also untangled the spare harness that came with the rover, and it, except for a few fried wires, is also surprisingly intact and complete. More untangling to do on that.

A few mysteries cropped up too, though. There was a purple/white wire in the dash, alone (not included in any harness bundle) with a lucas male bullet on one end, and a spade (female, I think) on the other. Anybody have any idea what that might be? I don't see purple/white on any of my diagrams.

Another is that I seem to have an extra wiper motor wire. There's Green (power from fuse box), Black (ground), The Red/Light Green and Brown/Light Green (high/low) from the schematic, but there's also a Blue/Light Green. (The Green Bible shows this as the Windshield Washer wire, so problem solved).

Also, I'm having trouble finding out how the warning (4-way) flasher gets hooked in. I have some ideas, but a couple of the wire colors are unique to that switch. I'm searching the board. I'm sure it's come up before.

And one final mystery, that fused Brown/Orange wire I mentioned in a previous post, actually terminates inside the cab. Since I have 2 wires (G/Y, G/W) hooked to the heater fan, I'm guessing the PO added that for the pass. footwell-mounted aux heater.

Now I just have to figure out the pinouts on the switches. The headlight switch hookup is specified in the schematic. The others I'll have to test, see what's what.

[printjunky]

Is that 4-pin section noted above a separate harness part? Does anyone know if there's a part # for just that 4 wire engine bay section?

[greenmeanie]

On GM vehicles purple with a white trace is the tach signal wire. the spade end goes to the coil and the bullet end to the tachometer.

[printjunky]

Good call, the PO did add some non-rover stuff as he felt appropriate (eg: Ford brake booster). So a tach wire might make sense (and it's removed).

The piece I'm still really stumped over is pictured. Wondering if this originally is a separate harness or part of a larger harness, if so what's it called and if anyone knows a part number or any other info about it? If I can't just replace that sub-harness part, I'll just get some parts and make my own, I guess.

Looks like the wires are:

Brown/Yellow - charge indicator wire from the alternator
White/Yellow - cold start/choke
Green/Blue - water temp
White/Red - Not Sure (should be ignition switch related, but maybe not)

[printjunky]

This is apparently the "engine harness" - makes sense. Josh at Brit wiring says $90. Our hosts online catalog says it's "$0.00," which is much more reasonable (Part# RNC527).

Even with this being my third Rover - and you'd think I'd be used to the irrationality by now ... $90 for a plug, four 4-foot lengths of wire, four bullets, and a wrap? Ouch.

Yeah, I know: kwitchyerbitchin'