Easiest Way to Locate Otter Switch Wire under Dash?

[Griffit]

As the title... now my dash is out I'd like to wire one of my spare dash swithes to short the otter switch and kick the fans in.

From the bible I see I'm looking for a green wire with a trace of another colour 'k' that doesn't have a colour code stated - pink? I see it runs to Block G but where do I find it, the back of the fuse box?!

As half the interior is now apart I suppose it's not the end of the world to take the fuse box out if needs be but the access is so hateful that if there's an easier way to do it I'd like to know! Is there anywhere else I can get into this wire or does it go straight through the bulkhead?

Thanks in advance

[The AJP Griff]

Griffit said:

As the title... now my dash is out I'd like to wire one of my spare dash swithes to short the otter switch and kick the fans in.

From the bible I see I'm looking for a green wire with a trace of another colour 'k' that doesn't have a colour code stated - pink? I see it runs to Block G but where do I find it, the back of the fuse box?!

As half the interior is now apart I suppose it's not the end of the world to take the fuse box out if needs be but the access is so hateful that if there's an easier way to do it I'd like to know! Is there anywhere else I can get into this wire or does it go straight through the bulkhead?

Thanks in advance

The block terminals on the back of the fuseboard have letter identification.if you dont fancy removing the fuseboard then you could go straight into the relay,like the previous owner of mine did.If i did this myself i would solder short connections onto the relay and use bullet terminals to connect to switch wires,this way it will be esier to replace the realy with a new one when the time arrives,as you could solder the new wires to the relay well away from the car.
To be honest it isn't too difficult to remove the fuseboard and do it properly.Theres some really helpful info on spends profile with regard to fuseboard plan.

[GreenV8S]

The easiest way to do this is to take two wires from the override switch out to the otter switch. While you're at it you can add a bulb or LED that is earthed through the otter switch to give you a 'fan on' light. The only connection you would need inside the cockpit is an ignition switched 12V supply for the light, and the ignition switched supply goes all over the back of the dashboard to power all the instruments.

[spend]

The green/pink wire can be found in the loom exiting the fusebox. If you unwrap the loom, make sure you note where any diodes are before re-wrapping (never know when you might need to find them again). To re-wrap the loom use proper loom tape and just stick the ends with insulating tape

You only need to switch the G/k to ground and the fans will activate. Its possible to go into the fusebox to find the wire, but its fairly stressed in there to make a splice. You can get connectors to re-crimp into the fuse box connectors, but that may be beyond the scope of what you want to do.

I'm not keen on running wires to the otter switch for 2 reasons, there are a couple of locations (the rad mount is quite a long complicated route) and you have to breach the tub which can cause water ingress problems.. Doing the wiring in the dash area seems much more sensible to me.

Dave
Dave

[The AJP Griff]

spend said:

The green/pink wire can be found in the loom exiting the fusebox. If you unwrap the loom, make sure you note where any diodes are before re-wrapping (never know when you might need to find them again). To re-wrap the loom use proper loom tape and just stick the ends with insulating tape

You only need to switch the G/k to ground and the fans will activate. Its possible to go into the fusebox to find the wire, but its fairly stressed in there to make a splice. You can get connectors to re-crimp into the fuse box connectors, but that may be beyond the scope of what you want to do.

I'm not keen on running wires to the otter switch for 2 reasons, there are a couple of locations (the rad mount is quite a long complicated route) and you have to breach the tub which can cause water ingress problems.. Doing the wiring in the dash area seems much more sensible to me.

Dave
Dave

And heres the ever helpfull Spend himself.
Dave,did the colours for the otter switch wiring ever change?I know TVR wiring colours didn't always stay the same throughout production as my a/c and a freinds a/c wiring were different!As long as you can identify the colours of the cable in the engine bay,then tapping into the loom in the footwell sounds like the better and easier idea

[spend]

I've only really seen changes in the shades of colour, in the 'generic' parts of the loom, which I guess is down to not all suppliers versions of green are the same (kind of thing). We know to hope for consistency with TVR, but we really love the all the idiosyncrasies

TBH thats one of the things that concerns me with the alt-ecu initiatives. Being an idealist I would like to see a def for ecu loom wiring colours that compliments the lucas loom, but doesn't conflict with any TVR wire colours (except where it joins the loom). Wire costs the same whatever colour it is, and there are an awful lot of combinations readily available...

As you say, you should be able to check the wiring colour at the otter switch, unlikely it will be changed at the loom connector behind the radio.

Dave

[GreenV8S]

spend said:

I'm not keen on running wires to the otter switch for 2 reasons, there are a couple of locations (the rad mount is quite a long complicated route) and you have to breach the tub which can cause water ingress problems.. Doing the wiring in the dash area seems much more sensible to me.

... but harder to do because access to the wires is far more awkward and it's harder to be sure you have the right one. On the V8S it's very easy to take wires through the bulkhead because the ignition harness goes through directly in front of the driver so it's just a matter of shoving another wire through the same gromit. Admittedly I've gone a bit over the top because I've got several extra wires and a vacuum line going through here now, but it's easy to get at and shove the odd wire through. Maybe it's harder on yours because the bulkhead design is different. Once through the bulkhead it's just a matter of cable tying the wire to the chassis every few inches and putting a couple of piggy back spade connectors on to the otter switch, which is imo far easier and less likely to go wrong that hoiking the fuse box out and breaking into wires.

[spend]

There is a grommet in the centre of the dash - have to remove the dash top, radio & cage and still its a struggle to get to.. There is also one for the wipers - really easy to get leaks as water runs down the wing onto that one + you have to get round the manifolds! It ain't easy to run wires into the engine bay I also pity the ones that have been done & missed the connectors at the bulkhead to allow separation of the loom if the engine ever needs removing You cannot add many wires to the hole and still allow the connectors to be manipulated thru the hole, so it is quite critical to consider how this is coupled up as well.

The way I see it is that there are frequently diodes bound into the main loom near the fusebox, so this needs to be unraveled at some stage.. and its better for owners to do that & at least know where those diodes are located (sods law & all that) IMHO. I would also always consider having a look behind the fusebox as essential preventative maintenance due to the chaffing of wires in that area. Personally I would make new crimp connections into the fusebox block connectors, but I accept I am probably an exceptional case in that regard

Dave

[Griffit]

spend said:

There is a grommet in the centre of the dash - have to remove the dash top, radio & cage and still its a struggle to get to.. There is also one for the wipers - really easy to get leaks as water runs down the wing onto that one + you have to get round the manifolds! It ain't easy to run wires into the engine bay
Dave

Thanks for the help guys, been out all day so no opportunity to try anything yet... As it happens I have the entire dash out right back to the bulkhead and have found the grommet in the centre of the dash as described above. Am I right to assume the wire I'm looking for runs through this very grommet? The loom is readily accessible in this location without the dashboard and all the various alarm, central locking, heating control boxes etc getting in the way and access is much nicer than working in the footwell ! Looks like a better place to make a joint to me !

[spend]

Yes it should be in one of those 15 way connectors

Dave

[Griffit]

spend said:

Yes it should be in one of those 15 way connectors

Dave

[makes way to garage quickly to check]

[Griffit]

Well that was easy!!! I found the two multiplugs and looked for the green and pink wire, checked it had a voltage with the ignition on then shorted it out with a small length of wire and the fans started running! That saves me pulling out the fusebox (for now at least), which was something I really wanted to avoid ! The heavy positive cable from my battery seems quite obstructive over the top of the battery in front of the fusebox, almost as if it's too short? Is this common?

For anybody elses reference, after the multiplug my green and pink wire changed to a purple colour before disappearing towards the engine.

Thanks Dave, excellent advice - those multiplugs are a godsend (for a man who doesn't want to pull the fusebox out at least!)

[spend]

Griffit said:

The heavy positive cable from my battery seems quite obstructive over the top of the battery in front of the fusebox, almost as if it's too short? Is this common?

Is the positive terminal on your battery on the LHS toward the front of the car? If folks fit batteries with the terminals the wrong way round they have to fit with the terminals to the rear???

Dave

[Griffit]

spend said:

Griffit said:

The heavy positive cable from my battery seems quite obstructive over the top of the battery in front of the fusebox, almost as if it's too short? Is this common?

Is the positive terminal on your battery on the LHS toward the front of the car? If folks fit batteries with the terminals the wrong way round they have to fit with the terminals to the rear???

Dave

That would explain everything... It's nigh on impossible to undo the battery terminals without double jointed wrists and spanners! The earth is on the RHS but the terminals are at the passenger end of the battery, not the fusebox end.I'll be wanting to turn that around then, I seem to think that I'll be needing to unbolt the battery box from under the car because the box has the lid riveted on from memory... Well at least I'll be able to reach the 10A fuse I dropped down the back ages ago and can't retrieve

[spend]

The black cable is not long enough to reach across! Sounds like some tw@rt has stuck the wrong battery in :-(

Dave

[Griffit]

Due to Pistonheads' no naming and shaming policy (and the fact that it's a relatively minor problem...) I shan't mention the fact that the last receipt I have for a battery (who I assume to be said tw@t) was from a well known TVR main dealer! Oh well, should it need replacing at least I'll know for the future, I'm not going to spend money needlessly, although my GF may claim that owning a Griff is just that