Engine wiring

[RobertGrieve]

Hello folks.

Having many difficulties with my wiring with later options like AC and twin fans.

Does anyone know what this connect is for?

Any help very much appreciated

Cheers, Robert

[mark10337]

If it is a black/green cable it should be the feed from the fan relay to the fan motor. This is a small separate loom on the picture frame. The black wire is the earth.

[RobertGrieve]

Cheers mark. This has confused me a touch more based on what I've read with comments that the fan relay was deleted on 4.2 cars? I also have a b/r and g down by the picture frame (I had thought the fan harness went straight onto these but not sure now! )

Picture attached of the wires at the picture frame

Rob

[Bobb]

I'm doing the same thing right now and started by identifying all connections in the new harness and in the car. I then tagged them all with tape and the nomenclature. It took three separate diagrams to identify all of them and I ensured that they all matched. Only then did I remove the old one and install the new one.
See my post here from last week.

[RobertGrieve]

Thanks Bobb. Your post has answered a couple of queries I had about the wiper earth and also that rather large red and yellow. My old loom from the firewall down was completely unidentifiable and not connected, pretty much destroyed. Im trying to see the arrangement on your loom photos for the fan harness but can't quite make it out.

Have you installed a fan relay or is that something your figuring out also?

Cheers, Rob

[mark10337]

Hi

Could you add which model of car you have to your sig, then we know which wiring will be the right one.

Black/Red is the gnd feed from the otter switch to the relay (W1)
Green is the 12v switched ignition feed from the main fuse to the relay (C2)
Green/Black is the live feed to the fan motor from the relay (C1)

[RobertGrieve]

Thankyou Mark. My car is a late series 1 LHD 2+2. Some have called it a 1.25 but not sure if people like that term here, I'm not sure i do!

Thanks very much for your help on the wiring. It seems I will need to buy another relay and the fan harness from SNG to complete the job!

Do you think that makes sense based on my car? Il update my signature now

Cheers Rob

[mark10337]

I have seen diagrams for the 4.2 S1 with and without a relay. Without the relay, the Green/Black wire isn't present, so it seems your loom is for one with.

It is simple enough to wire it without the relay. Connect the Motor+ to the Green feed from the fuse and the black/red to the -neg terminal on the Motor. Then when the otter switch turns on, it allows a connect through to ground and thus turns the fan motor on.

Relay or not, with the relay the current was still being drawn through the fuse from the same place as it was a shared 12v feed.

[RobertGrieve]

Thanks Mark - your absolutely right I have seen several variations of wiring diagrams with or without relays. The car is running a later twin fan.

It is tempting to wire in the relay seen as it seems my loom is designed for it - although if I can just block off some wires and directly wire in the fan motors at the picture frame connection that will save me some pennies!

Rob

[Bobb]

Have you installed a fan relay or is that something your figuring out also?
Cheers, Rob

Hi Rob,
I left the fan and horn relays as stock. The alternator relay, voltage regulator, and 3AW warning light gizmo plus the entire alternator harness are now redundant due to a modern Hitachi alternator. I made a new harness using the three required wires and am now looking at a way to sleeve them with something that looks reasonably original. After snooping around sewing and knitting shops, then a ton of research online for small-ish looming, knitting or weaving machines I read a great little hint on Hackaday ( http://hackaday.com/blog/ ) where he used shoelaces to cover small wiring harnesses. They're hollow and come in a wild array of sizes and patterns. Stay tuned.

[Bobb]

I almost forgot....the new harness will have a LOT longer lead to the bonnet plug than is required. Don't go off all half-cocked and solder the plug to the harness before it's test fitted. Mine came from SNG and I've now got to undo all that work, remove many cm of wire then resolder the whole thing. It's long enough that it touches the ground with the bonnet closed.

[RobertGrieve]

Thanks Bobb.

Great tip with the braiding on the harness. Will definitely look at that. I think half my problem is figuring out what was stock and what has just been messed with!

Rob

[RobertGrieve]

One issue I've found that seems to be caused by my car having AC and a rearward facing alternator, is that my alternator harness falls about 15cm short of the alternator because it can't quite reach the picture frame

Has anyone had any experiences extending the wires? They're obviously quite chunky with the current so I'm reluctant to cut and extend. But I don't think I have any options.

I guess the original harness may have been a later version so I've probably gone and ordered the wrong one...

Rob

[johnetype]

Extending the alternator harness is difficult but not impossible, the 60 amp main feed wire being the challenge. I would use two tubular crimps to insert an extension, covered with heatshrink and done at a point where you can hide it within the loom sleeving. Autosparks can sell you the correct wire. Alternatively, as the alternator loom is separate you could just buy a new correct length loom. Or you could just do without the A/C

I would not advise running without a fan relay, especially as you have twin fans, you run the risk of burning out the Otter switch contacts. The fan relay(s) are mounted on a plate bolted to the RHS of the picture frame. I say relay(s) because on a car with A/C there should be two relays. One relay is driven by the Otter switch to turn the fans on, the other relay turns the fans on whenever the A/C compressor is energised.

John

[RobertGrieve]

Thanks John. I had played with the idea of just putting it back to non ac, but felt it would be a bit of shame to have all the interior kitted out for it and then having no means of fitting the compressor back at a later date (mine needs refurbing).

I will check out autosparks for the correct wire and cheers for the advise on the relays. When I took the car appart I did not find any evidence of a relay being fitted, but will never know for sure due to the poor condition, as you say I do not want to burn out the otter contacts.

Rob

[Polse7317]

May be helpfull ?

[RobertGrieve]

The more wiring diagrams the better - ta very much!

[AshM]

Robert

I can print all of the wiring diagrams in the reference section on here in any size of print - A3,2,1,0. Colour.

No charge - I have access to a plotter at work. Just let me know what helps.

If you (or anyone else) wants any diagrams them PM me. Delighted to help the cause for a few pence of postage.

I have a laminated A0 diagram on my S2 on the workshop wall - it gets a lot of use and (dare I admit it) I stand studying it during coffee break

cheers
Ash