[Wedge] Relay feeding the front lights -

Odd · Postby **Odd** » 12 May 2010 19:20

Friends,
for those of you following the discussion on the TR8 mail list regarding this headlights relay idea I can tell you
the prototype unit is now done:

So far I've built the first one (I'm building two clusters, one for my own TR8 and one for my friends TR8) and can now
state in detail what's needed and how to do it all. We have opted to include a relay for the front fog lights as well
since here in Sweden we must drive with either dipped headlights OR other driving lights lit all the time - and for this
we use the front Cibie C35 fog lights. And the fog light switch can benefit from being spared the heavy electric load,
just as the head light switches... So in our interpretation of this idea there are five relays in the cluster.

Examining our cars we found the easiest way (and also easily reversible! for a concours situation maybe?) was using
the white 3-pin Rists connectors (found beside the red Rists 3-pin pod motor connectors) as the interface point.
Just open the two white connectors up - and stick the new 3-pin connectors to/from the relay cluster into them - done!
The fog light interface point was created in a similar way but here we had to cut and re-direct one Red/Yellow wire
in order to create an interface point moved inboard of the right side bulk head (just as the ones for the headlights
are). For this exposed connection out in the light pod well we will be using a modern weatherproof 2-pin connector
- since water is a much more common occurrence out there as compared to inside the engine bay front corner...

Material needed to build one cluster like this was:

Thinwall electric wires:
0.9 metre of browN 56/0.30 4mm2 39amp cable (for the +12V feed)
0.85 metre of browN 28/0.30 2mm2 25amp cable (for splitting up and connecting the +12V wire to each of the relay fuse in-terminals)
0.6 metre of Black 44/0.30 3mm2 33amp cable (for the earthing point connection) +
0.4 metre of Black 44/0.30 3mm2 33amp cable (for 'shorting' the Rists connectors earth pin to each other in each end of this contraption)
1 metre of Black 32/0.20 1mm2 16.5amp cable (for splitting up and connecting the earth wire to each of the relay coil's earth terminals)
0.45 metre of blUe/White 28/0.30 2mm2 25amp cable (for connecting the old pod cable to the right side main beam relay's out-terminal)
0.45 metre of blUe/White 32/0.20 1mm2 16.5amp cable (for connecting the old feed cable to the right side main beam relay's coil terminal)
0.4 metre of blUe/Red 28/0.30 2mm2 25amp cable (for connecting the old pod cable to the right side dip beam relay's out-terminal)
0.4 metre of blUe/Red 32/0.20 1mm2 16.5amp cable (for connecting the old feed cable to the right side dip beam relay's coil terminal)
1.4 metre of blUe/Slate 28/0.30 2mm2 25amp cable (for connecting the old pod cable to the left side main beam relay's out-terminal)
1.4 metre of blUe/Slate 32/0.20 1mm2 16.5amp cable (for connecting the old feed cable to the left side main beam relay's coil terminal)
1.4 metre of blUe/pinK 28/0.30 2mm2 25amp cable (for connecting the old pod cable to the left side dip beam relay's out-terminal)
1.4 metre of blUe/pinK 32/0.20 1mm2 16.5amp cable (for connecting the old feed cable to the left side dip beam relay's coil terminal)
0.75 + 0.75 + 0.4 metre of Red/Yellow 28/0.30 2mm2 25amp cable (for connecting the old re-directed fog light feed cable to the fog light
Rists connector and the 'Weatherproof' fog light connector to the fog light Rists connector + the relay's out-terminal to the Rists connector)
0.4 metre of Red/Yellow 32/0.20 1mm2 16.5amp cable (for connecting the Rists connector to the relay's coil terminal)

5 4-pin NO relays - with built-in blade fuse holders
5 interlocking relay sockets
20 1/4" flat female blade terminals (for above sockets)
2 20Amp blade fuses (for the [now possible] two 100+ Watt main beam filaments)
2 10Amp blade fuses (for the two 55 Watt dipped beam filaments)
1 15Amp blade fuse (for the twinned 55 Watt fog light filaments)
2 ID 8mm ring terminals (for connecting the +12V wire to the starter solenoid and for connecting the earting wire to the right chassis frame M8 earthing point)
2 3-pin Rists connectors (with terminal pins)
1 2-pin Rists connector (with terminal pins)
1 2-pin 'Weatherproof' connector (with terminal pins, for the fog light wire junction)
3.8 metres of 1/4" PVC sleeving
~1.5 metres from an old roll of black non-adhesive PVC harness tape
0.8 metres of shrink tube, with heat glue lining (for sealing all the cable-to-terminal ends)
~50-60 2.5*75mm cable-ties (to hold the emerging wire bundles together while they're not yet harness-taped-up)

I'm sure most if not all of this can be sourced from places like British Wiring in the US and Auto Sparks in the UK
- if you cannot find it in your local auto electrics shop... I'll report back when they are fitted and operating so I have some results to deliver...
Cheers,
/Odd

My two 1980 Wedges...

Beans · Postby **Beans** » 12 May 2010 20:23

Nice set up [:)]

<center>

1980 TR7 DHC (my first car, currently being restored)
1981 TR7 FHC Sprint (better known as 't Kreng)
[url="http://www.tr7beans.blogspot.com/"]My Weblog[/url]</center>

Rich in Vancouver · Postby **Rich in Vancouver** » 13 May 2010 13:57

Odd,
If you decide to produce these I would be interested in one.

Cheers,
Rich

1975 TR7 ACL764U

Odd · Postby **Odd** » 13 May 2010 15:30

<blockquote id="quote">quote:<hr height="1" noshade id="quote"> Odd,
if you decide to produce these I would be interested in one. <hr height="1" noshade id="quote"></blockquote id="quote"> No, I will NOT be building/marketing these. Far to much material have to go into each of them
to make it a viable hobby project. That's why I've listed (in detail!) what was needed to build one.
I'm going to make a .pdf write-up when I have all the data...
/Odd

Odd · Postby **Odd** » 13 May 2010 17:19

<blockquote id="quote">quote:<hr height="1" noshade id="quote"> Odd,
great write-up on the light relays.
You write: "...here in Sweden we must drive with either dipped headlights OR other driving lights lit all the time - and for this we use the front
Cibie C35 fog lights. And the fog light switch can benefit from being spared the heavy electric load, just as the head light switches... "

In Canada, new cars have had Daytime Running Lights for quite a while and I want to use my TR8 fog lights as Daytime Running Lights as well.
Are you planning to change the Fog lights circuit to turn on/off automatically with the ignition switch? That is what I would like to do with the
fog light relay circuit so that I can leave the Fog light switch ON all the time (and not worry about a dead battery!). All my SAAB's have that
feature for the main headlights and I love it! <hr height="1" noshade id="quote"></blockquote id="quote"> Salut,
I've already done that to my TR8 (years ago when I had the entire main harness in the dash free and opened up).
I did it via a relay, a diode and some wires that operate from the ignition circuit (White cables) but;

It would be just as easy to implement it into this new relay cluster:
it's just a matter of bringing the power from a White (for instance the White cable feeding the ballast resistor assembly etc,
it passes conveniently close to the new relay cluster position) or a Green cable (since the W or G are only energized when
the ignition is ON) up front to the relay cluster. There you fit a six amp diode (1N4006 - cheap and easy to find) between this
new (16/0.20 0.5mm2 11amp) W or G cable and the plus side of the fog light relay coil.

(For extra assurance you should fit such a diode as well to the Red/Yellow fog light 'control' cable ending in the same spot.)

_If_ you want the fog lights to be OFF when the dipped headlights are ON (it's a legal requirement over here at least) you
could either fit a NC relay cutting the power to the fog light relay when the dipped headlights are energized (= probably
the best solution but it will add one more relay to the cluster) or you could exchange one of the two NO dip beam relays
for a 5-pin change-over relay that feeds its outgoing power on pin 87 to the dip beam filament when it's energized and
onto pin 87A (to the +12V side of the fog light relay) when it's de-energized, thus the fog lights would lose their juice as
soon as the dipped beams are engaged. I'm not sure if there are any 5-pin change-over relays with a built-in fuse holder,
but I wouldn't be overly surprised if there were...
/Odd

DNK · Postby **DNK** » 06 Jan 2012 00:41

Odd can you send me full size pics of what you posted?

Don
"No More Cars For You"
71 TR6- Perpetual remodel
80 TR7 V8 Kick in the pants

Odd · Postby **Odd** » 06 Jan 2012 09:22

I think they are available on the TWOA CD-ROM...

whitenviro · Postby **whitenviro** » 04 May 2012 20:48

I dredged this topic up from the archives; the search tool seems to work a lot better these days!

Odd, you seem to be the expert on adding a relay in the headlight circuits. I don't think I'm up to building the type of set-up you show here. I know Victoria British puts out a relay kit, but the review seems to be they are cheaply built and confusing to install. I see these pre-built harnesses on eBay; any thoughts on whether or not they are suitable?

http://www.ebay.com/itm/H4-Car-HID-Xeno ... 830wt_1112

[/img]
1980 Pageant Blue DHC with removable hardtop.

Odd · Postby **Odd** » 05 May 2012 14:49

Personally I wouldn't buy something generic like that
- there's lots of work left to make it fit the Wedge...

whitenviro · Postby **whitenviro** » 05 May 2012 16:03

Thanks!

[/img]
1980 Pageant Blue DHC with removable hardtop.

Anonymous

[Wedge] Relay feeding the front lights -

[Wedge] Relay feeding the front lights -

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