Spare or vacant relay socket

This relates to a 135 TF.
Can anyone tell me if there is a vacant socket that is "pre-wired" in any of the standard OEM relay control boxes such that I can insert a standard or micro relay that will have its control coil energized when the ignition is turned on, and that would enable me to take a feed from that relay base to another externally mounted relay.
In simple terms I want to fit an extra relay in a position yet to be determined to control a supply to "extras", and I want that relay switched on by fitting a relay into a standard control box "somewhere" in the car.

Sounds like to much like buggerising about to me just intercept the accessory feed wire from the if switch and run to your relay from there

It’s a matter of which fuse/relay box you have & which facilities are installed. Let us assume it is a later box utilising the miniature blade fuses & small form relays; if you have aircon then all the ways will be occupied, if not you could have one socket on the front of the board & two behind.
This isn’t an exhaustive analysis, only a glance at the circuit diagram & one at the board layout to possibly point you it a useful direction.
You must however look at these yourself & make your own mind up.
The point that Cobber made is of value, you can buy small fuse/relay panels off eBay to introduce into your car, possibly under the bonnet. I have done this by making my own, but a bought one will give you the greater adaptability you seem to require.
My car acts as a test bed for various projects & without these options I could do little in the way of my endeavours.
M

Del can you remind us which TF you have, the Mk 1 with the Lusas electrics and sqare key fob or the Mk2 with the Pektron electrics and rounded fob ?

Yes, it’s a 2003 TF 135 with the old Lucas style fob.
The aircon slots do seem to be an option. What I’m seeking is a circuit that automatically switches On once the car is started but aircon might not do that unless it is left always on.
I only need it to power an externally mounted relay that I will mount in the front under bonnet compartment. From there I will take a feed into the cabin to supply the dashcam.
I will also then take a feed to any DRL affair iintroduce.

What I don’t want is any DRL halo illumination around headlights once the headlights are switched on, and I definitely don’t want alternate flashing white/yellow for a halo indicator.
If the circuitry in the standard package that comes with a halo system can do all that great.
But I’m not keen on cut/splice the standard loom to join it all in.

I still think that this is all way more complicated than it needs to be.
There will be an accessory feed wire coming from the ignition switch to the fuse box. All you need to do is intercept this wire and splice in a feed to your new circuit relay. Simples!

Cobber's right. If I understand you correctly, there is probably no need for anything fancy. For my DRLs (which are exactly the type you don't want!), I used a piggyback blade fuse inserted into one of the accessory (ignition switched), fuse sockets on the fuse board under the steering wheel. I can't remember which one but all the fuse box info is on This post by Roverlike .

My guess is your dash cam will be 5v, powered by a USB adapter this would normally plug into your lighter socket. I have built a dedicated USB system into the car where I can pick up power for the various devices I use (don’t ask).
I wouldn’t expect you to follow my route, but a simplified version could be adopted.
My camera is mounted next to the rear view mirror on the passenger side & my nearest USB outlet is in the footwell fuse box. I popped off the trim up the A post & over the windscreen & ran it around there, a cutout being made for the cable to exit. I use the fag lighter circuit to run the main USB sockets for when the ignition is on & an “auxiliary auxiliary,”which is powered constantly.
The DLR system has to be dependent on your kit. I was an early adopter of these systems, designing & building my own, which is crude in comparison to the modern offerings, it has been reliable & I’ve no intentions of changing this basic system, however I have supplemented the system with wing mirror mounted white light, which act as indicator repeaters.
The repeaters on the front wing are of little value these days as most vehicles one comes across have wing mirror repeaters & who now noticed an inch square orange lights lamely blinking when everyone else has “startlingly loud 150db” lights.
There are so many options with stuff like this & it all depends on how confident you are with car electrics/electronics, I’m in & out of this stuff almost daily to the point where I can look at wire colours & tracers to identify circuit families if not actual functions.
But there again I’m a bit odd.
M

PS those piggyback blade adapters that Bruce alluded to are very useful & I use them for temporary application, a permanent installation is preferable but there’s no reason not to use them long term providing you watch the total circuit current & you make a good job of the crimp.
M