Front wiring loom - How does it get there

[Johno]

I'm struggling in a very tight garage to see where the front loom that supplies the lights etc is fed from the main loom down there.

I am being very anal at the moment and the 2 stage fans that my new loom will support I want to run down the wings to the front and along the front bulkhead and over the top of the fans like the current set up. The problem being I can't see a route down there at the moment, and jacking it up means opening the garage door and it's too dashed cold for that . .

I am trying to minimise the amount of wiring in the engine bay completely, and unless I have to put them through the engine bay I'll try not too....

I'm sure I'm being a numpty, but any help much appreciated and may save my butt getting very cold this evening . .

[Johno]

Quinny said:

Hang on Johno Pic coming up

Legend .. . .

[spend]

Out the passenger side (dash) to the inner wing, over the inner wing into the nose cone area. Should be able to see them all just behind the n/s headlight.

Dave

[Johno]

As I suspected, the difficulty being I can't see where it comes in to the loom behind the dash either. Dash is on bench currently as well . . .

I've got the inspection hatch of the passenger inner wing and can not see any wiring going over the wheel arch, in fact there doesn't appear to be a hole at all. Therefore assuming it comes down the drivers side and across to the passenger side at the front, but can't see through any of the many holes any wiring or obvious route for it either.

I'll have to have the o/s wheel off and have a look into the back of the pod and see what I can find . . . .

Thanks for the photos and comments guys . .

Maybe I'm being a little to anal

[spend]

Johno said:

As I suspected, the difficulty being I can't see where it comes in to the loom behind the dash either. Dash is on bench currently as well . . .

I've got the inspection hatch of the passenger inner wing and can not see any wiring going over the wheel arch, in fact there doesn't appear to be a hole at all. Therefore assuming it comes down the drivers side and across to the passenger side at the front, but can't see through any of the many holes any wiring or obvious route for it either.

I'll have to have the o/s wheel off and have a look into the back of the pod and see what I can find . . . .

Thanks for the photos and comments guys . .

Maybe I'm being a little to anal

N/s look closer (well feel) - its normally in the 'crack' toward the inside IIRC.

At the dash there is 'hole' in front of the door, under the screen pillar (ish) you should be able to see the harness heading to it. There are a few block connectors there.

The engine loom goes through the bulkhead behind the stereo, AFIK the only wiring down the O/S wing is the brake res warning (and poss drivers fan if you have one).

Dave

Dave

[Johno]

Still struggling to find it in the n/s and definitely not in the d/s. The only wiring going down there is the indicator ! Although I can get the wiring across the back of the dash and throught the d/s inner wing, but going to re-investigate the near side.

If it does go down the near side, which I think is correct, Ij just can't ee me getting the wiring down there, but we'll see . . . back to the garage . .

[spend]

Johno said:

If it does go down the near side, which I think is correct, Ij just can't ee me getting the wiring down there, but we'll see . . . back to the garage . .

Its not too hard, but need to do it in 2 stages, dash - side repeater hole, side.. - undertray. I managed it with bits of curtain wire in about 30 mins... Then 45 mins because I dropped the string catching the side repeater connector

Dave

[Johno]

Found it . . .

The picture below shows the entry wound . . . Not easy to find when the doors barely open, your 6'3 and 15+ stone and your trying to lie upside down realising you can't get out of the footwell and home alone. . . But I'm

I can get a coat hanger down there for it's full length, but I'm gonna need a long piece of equally stiff wire and then I'm laughing . .

Picture show entry with foam baffling removed.

Thanks all, it took some time, and perhaps I have a career as a contortionist (sp) . . .

[AntonyJ]

Johno said:

Found it . . .

The picture below shows the entry wound . . . Not easy to find when the doors barely open, your 6'3 and 15+ stone and your trying to lie upside down realising you can't get out of the footwell and home alone. . . But I'm

I can get a coat hanger down there for it's full length, but I'm gonna need a long piece of equally stiff wire and then I'm laughing . .

Picture show entry with foam baffling removed.

Thanks all, it took some time, and perhaps I have a career as a contortionist (sp) . . .

Johno , the other problem you will have is that the aperture going over the inner wings gets quite small.
I fed my heater fan hose over there and had to oval the round tube to get it over.

Dont the 500's have an access panel on the N/S inner wing?
Sure I have seen one the later bodies.
This will help you to see in there, I think its behind the AFM.

Ant

[spend]

Johno said:

Found it . . .

Not easy to find when.. your 6'3 and 15+ stone and your trying to lie upside down

Ooerr... I've heard you poorly endowed porkers have that problem

Dave

[Johno]

Worthy of an attack those comments . .

Now I knw which wiring it is I think the best solution is to come up with a in line fix that can be driven from the ECU in the footwell.

So after all that, I'm now going to try and solve it in the footwell

It's an Emerald install and I am going to run 2 stage cooling. With the Emerald rather than running fans at half speed, it run's one fan and then the other, which some how feels like the right thing to do . .

I'll have a chat with the guy who's building my loom tomorrow. . .

[Uncle Fester]

Johno said:

Worthy of an attack those comments . .

Now I knw which wiring it is I think the best solution is to come up with a in line fix that can be driven from the ECU in the footwell.

So after all that, I'm now going to try and solve it in the footwell

It's an Emerald install and I am going to run 2 stage cooling. With the Emerald rather than running fans at half speed, it run's one fan and then the other, which some how feels like the right thing to do . .

I'll have a chat with the guy who's building my loom tomorrow. . .

Assuming you mean Paul Dove, you can get the fans to come on staggered start like you said, but at half speed then switch to full speed. Thats how I got mine done.

Also get the relays fitted so that the fans can run on after the ignition is switched off just like a mod-wise kit.

These keep the ECU powered up after ignition switch off.

This won't work yet, but Emerald are releasing a firmware upgrade later in the year that will make it work.

[ruaricoles]

Johno said:

With the Emerald rather than running fans at half speed, it run's one fan and then the other, which some how feels like the right thing to do . ..

Actually, it'd be better to run both fans at half speed rather than one at full speed. If you've got one fan running and one not, in traffic the running fan will recirculate air through the static one and slightly reduce the overall efficiency. Unless you don't have a fan cowl, in which case it won't make much difference. Might also be quieter with both fans at 50% rather than one at 100%???

Ruari

[Johno]

Fester

I was in your engine bay yedsterday at Paul's workshop.

It prompted some thinking and was a useful template for a few ideas . . .

[spend]

The 1/2 speed is possible by using 3 relays in the fusebox, but requires an extra wire from the fans back to the fusebox.

I don't know if it might be better to do this using 2 extra relays closer to the fans though.

Dave

[Johno]

This is what I intend to do, to bring the thread to a summary if it helps anyone.

The Emerald has two switchable outputs for the twin fan control, so it controls one or both fans, rather than running them at half speed.

I disagree with half speed for the following reasons . . . Not everyone will agree and they are not scientific and are my opinion only . ..

1 - The fan motors are designed to run at a particular speed, changing this set up does not feel right.

2 - I don't want both fans almost constantly running at half speed.

3 - Having a single fan running at full speed will not be any less efficient than 2 running at half speed.

4 - It is easier to wire in my set up than the half speed set up.

5 - Isn;t it more efficient for the battery/alternator for the fans to run at full speed than half ???

6 - Half speed fans don't seem like they'd the skin off a rice pudding

Additional to these comments is that every other set up I see to run the fans anything other than their normal operation involves a whole bunch of additional loom, relays etc that I've gotta find a home for in an engine bay notorius for being unkind to electrcical connections. Im a 10k miles a year in all weather driver of the car and I want a neat engine bay with no more wiring than absolutely necessary in it. Changing the ECU was a great opportunity to ditch the loom that's in there currently. I don't want tie wrap lumps of wire anywhere in there, the odd one along a chassis rail I can live with, but trying to relays in the light pods was an option but they're in use already.

For example, HID conversion. I had 4 ballast boxes to find a home for. All 4 are in the rear of the front light pods bolted through the wheel arch, or in the front of the light pods bolted in as well. I have seen them in the engine bay, which for ballasts which get hot enough already seems the wrong thing to do and looks IMO untidy and unneccessary. The pods have then been weather proofed so they aren't just a big scoop for water to puddle. Anal, but neater, and less prone to failure later.

Therefore with the Emerald running 2 switchable circuits I am going to establish a short loom from the ECU with micro relays and a permanent feed from the battery. The existing fan wires will be removed from the back of the fuse and connected into this new loom so the relays remain in the footwell, and the existing wiring is utilised to run the fans, individually as required and without ignition on.

The permanent feed from the battery will be provided ahead of the Emerald firmware update later this year so they will run on after ignition has been turned off.

I intend to mount the ECU above the glove box like in your car Fester, and the micro relays will go up there as well.

I therefore will not need to run any new wires through the engine bay, the relays are easily accessible and are kept dry and the new short loom will have connectors allowing easy removal if necessay.

I have fitted a LED tell tale in to the column cowl at the same time I put in my shift lights, and the fan tell tale can then be wired in to the 2nd fan relay, so it alerts me when both fans are in operation rather than being on when the initial fan starts.

Thanks all for your help and I am sure other will do something different, but thi suits my thinking

Edited by Johno on Wednesday 20th February 18:20

[spend]

TBH J, I did the design so I could use half speed... But even with 2 otter switches I leave it switched (I have control to do 1 fan /both fans off either otter switch) so that both fans come on early. They just get the job done faster I still like the 2 otter switches - just makes a fail safe if one fails...

The 2 arguments for using 1/2 speed staging are to stop the power surge, but good electrics do this anyway, and to assist in blowing air in hot engine bay - if it needs cooling down use the over-ride / ceramic exhausts/bandage ... IMHO.

Dave

[Johno]

Cheers all, I have tonight got the wiring for the lambda through the pod and into the back of dash through the wing following the existing loom. Was a doddle to do in the end, 10mins.

I had the loom built with a spur and connector for the lambda . . .

For the fans I had the loom built with a connector spur from the loom at the back of the dash so that I could take the 2 power output wires from the back of the dash and graft them onto the spur. Therefore no need to run anymore wiring to the front of the car.

Both lambda anmd fans are on connectors and not hard wired and there is no other wiring in the engine bay.

So 2 stage cooling, which run on after ignition and lambda without all the normal gubbins.

Also shift light and fan tell tale have been built onto loom spur as well so no more wiring for me, just connect em up . . .

Nice, neat and tidy

(Quite unusual for me ! ! !)

[HRG]

If you're ever struggling with pushing cable in the future a piece of 16mm or 25mm trunking lid makes an excellent rod Just tape the cable to it and push away.

For my sins I was a cable monkey years ago...