It's Electrics now, advice please

[kenny]

I've started on the electrics part of the rebuild now. As someone said to me last month on here "have some bottle" and get the jobs done.
Well I'm a complete electrical numpty but I'm attempting to put a new full loom in car. So far so good I've joined car loom to engine loom to dash loom,via soldered joints and it's looking quite neat. I would like to check circuits tomorrow and put some contolled power through them but before that I have the first few of probably millions of questions when it goes T1ts up

1) I seem to be short of the headlight flasher in engine bay as I have two black and red wires with no home. I was supplied with the car IMO relays and the headlight main relay is an IMO 12V 50A unit. What flasher should I buy tomorrow spec. wise? to match....can't find it in the book.

2) Where my loom splits into 3 under footwell I have a black/white wire spare, I also have one in engine bay. I assume this is HRW which I don't have, shall I snip it?

3) I have no anti theft unit and my wires are just dangling behind dash. Just looked it up on search and guys have said bypass it......so I will , Am I correct in saying that I just join red/green to red/green and tie up the purple/black and black wires.

4) My oil gauge fitted is a capillary but I have a brown and white wire for pressure gauge on engine loom. Is this for an oil warning light on existing gauge or am I best off finding an electric gauge for this wire......there is no electrical connection on pipe fitting on block.

5) Red/White wire (thicker than the one on back of clocks) is homeless, off dashboard loom near steering column, any ideas please?.......

The most electrical thing I've done in my life is fixing the fairy lights, but I guess if you just splash out and pay someone you'll never learn and won't be able to help people yourself one day.

Thanks again for any answers to any of the above.

Kenny

PS Still not as hard a job as getting H/rake cable and fuel line through with body on

PPS Please excuse my dreadful electrical teminology and ignorance

[msd1107]

Kenny,

I have at 36 S4, so it looks like some of wire colors are different.

But do not connect PB to B. That sounds the horn. PB comes from the horns which are fed +12 from the fuse block via the P wire. It also goes to the horn button which sounds the horn when earthed when the button is pushed. B is earth.

Connect the two RG wires (on the 36 this is W) and it connects the ignition switch to the coil.

Why do you not mount up the anti-theft switch. It is better than nothing. And you could add a keyed battery disconnect in the boot. Unless the potential thieves are determined, that would stop them.

Good luck on the rest.

David
1968 36/7988

[types26/36]

Kenny,
I cant help with the specific wireing of a +2 but the Lucas wireing code may help identifying some wires. Here is the MG and Jag links although they should both use the same colour codes.

http://www.mgexperience.net/article/lucas-colours.html

http://www.jcna.com/library/tech/tech0014.html

[kenny]

Dave, thanks for that re. the wiring on Anti-theft. I will bypass it in the way you say R/G-R/G and just leave the other 2. Car will hardly be used so if I do leave it anywhere I'll just knobble it some other way

Brian, studying those links you posted now.........many thanks pointing me there.

Regards,

Kenny

[cliveyboy]

Kenny
My bit of additional advice is get a copy of the wiring diagram blown up larger and mark any modifications you do onto it. I have my big diagram on the wall and it makes life easier when working on the electrics.

Cliveyboy

[kenny]

Good shout Clive, I've actually done that although I had to re-write the colours for the wiring as they just came out in blobs of black

Surely w/diagrams could be drawn easier than they are, I go dizzy trying to trace that red/green wire through three laps of the drawing

Kenny

[msd1107]

Kenny,

I can empathise with chasing the lines around the page, even with a blown up diagram. I got tired of it.

So I did the geeky thing, and made a spreadsheet of the wiring diagram.

Now I can look at a component and see what component and what color wire is coming in and going out. Plus if it goes to a connector, what the eventual source and destination is.

Too bad it is not for a +2, but it is for a S4.

David
1968 36/7988

[frearther]

Just be sure not to let the smoke get out

[kenny]

Sounds like a great idea David pity it's not for a plus2.

Seriously though I'm really struggling now. Looms in and 98% connected. Put a 12v controlled supply to solenoid to start checks. Lights are a problem. I was supplied with the small black oxo sized IMO relays for lights and I'm sure wiring is wrong to them....too hard to waffle and explain here but what units can I buy with a hint of where to put the wires to them, struggle struggle struggle

Kenny

[msd1107]

Kenny,

Kind of hard to say from here. Each relay should have one wire for switched +12 which would be connected to what on the S4 is the U (blue) colored wire from the control box.

Then there should be another wire that turns on the relay and would connected to the UN and UB wires from the hi-lo beam switch on the steering column.

There should be a switched +12 from the relay to the headlamps which would be connected to the UB and UR wires to the headlamps.

And finally, there should be a ground wire that would be connected to the BR wire which eventually goes to earth.

I don't know if this helps, but good luck. Are there any other +2 owners that have the workshop manual who can help?

David
1968 36/7988

[kenny]

Many thanks David for help and info. appreciated. I will summarise step by step where I'm at as we speak now. I had John.Houston a fellow +2 owner and member of this site around yesterday to lend a hand (we swap a days work with each other every week on our total rebuilds)

Heres where I'm at

1) New loom is now 95% installed (just odd bits like heater and steering coulumn remain)
2) I am using a 12v 5A transformer attatched to the power in side of the solenoid to give the power for testing purposes.
3)I was supplied in my box of bits two IMO 12/14v 50/60A relays for headlights. One is behind dash, one in engine.
4)On the engine loom 2 black/red wires emerge near relay. Manual diagram says flasher. Went to Lucas agent and auto-electrical repair shop to buy one, guy says you don't need one!!!! The relays are enough. So the 2 wires are still dangling.
5)I turn ignition on to start and solenoid clicks no problem.
6) Flick light switch to sidelights nothing, flick switch to headlight and relay clicks but no lights also no dash lights.
7) Put 12v supply to light switch "out" and sidelights work proving my feeds are OK the length of car.

To summarise I don't know if I've got the right relays, whether they are wired up correctly or whether this is an earthing problem. Are my 2 unconnected red and black to flasher wires involved although there is no power in them.........stumped as to where to go next.

Again I stress I am an electrical incompetant, but you have to learn sometime. Plus buying a project like this and farming the work out defeats the object of it being a winter hobby.

Thanks for any comments made on this.

Kenny
Edited to add, should I junk these after market relays in favour of the correct 6ra items, I'm only using these as they came in the kit and I am working to a budget for total rebuild.

[elansprint71]

When I fitted the dreaded Paul Matty loom last year I was in fear & trembling of a China Syndrome-like meltdown when I connected the battery; I found a little rechageable 12v 1.3 ampHr lead/acid battery at Maplin (own brand) which had enough guts to power window motor, wipers, etc and even enough to just give the starter a twitch. Certainly saved on brown trousers. It was about 9 quid, iirc.

Cheers,
Pete.

[M100]

No need for the small battery Pete, just fit an inline fuse of say 5 or 10 amps inline with the existing battery and then increase it progressively to 30 or 40A when you try out the lights, heater etc.

If you have a multifused vehicle rather than a 2 fuse lucas special then a decent mulimeter on amps range connected across each empty fuse holder in turn helps to stop any expensive smoke escapes almost before they happen.