• Hey Guest!
    British Car Forum has been supporting enthusiasts for over 25 years by providing a great place to share our love for British cars. You can support our efforts by upgrading your membership for less than the dues of most car clubs. There are some perks with a member upgrade!
    **Upgrade Now**
    (PS: Upgraded members don't see this banner, nor will you see the Google ads that appear on the site.)
Tips
Tips

Wedge Mystery TR8 relay?

Share this page

I would say it is for the radio so you dont have a constant power to it as many would require. Some batteries and charging systems cant handle the drain so using a relay helps.
 
Well, still not quite sure what it does.

The UR (blue/red) wire that it is spliced to is part of the fog light/low beam system. It appears it is switching some part of the purple system (always on) based on power to the UR wire.

I also found that I did blow the 35A 5-6 fuse in the fuse block.

It isn't part of the radio (at least as I have it wired now), as that all works with the red wire disconnected from the relay. In fact, everything feed by the purple wire seems to work, the only thing I haven't checked is the fog lights. I can't quite decipher the diagram for that switch. Is there supposed to be some interaction between low beams and the fog lights?
 
Darrell_Walker said:
Is there supposed to be some interaction between low beams and the fog lights?
Click to expand...

I was going to suggest it might have been hooked to the fog lights.

And, yes, fog lights are ~supposed~ to be on only with low beams. High beams give too much reflected light from the fog.
 
Mickey Richaud said:
Darrell_Walker said:
Is there supposed to be some interaction between low beams and the fog lights?
Click to expand...

I was going to suggest it might have been hooked to the fog lights.

And, yes, fog lights are ~supposed~ to be on only with low beams. High beams give too much reflected light from the fog.
Click to expand...

Do you know how the fog light switch works? Is the switch itself supposed to only turn on the fogs when the low beams are on? Perhaps that function of the switch failed, and this was a work around?

Anyway, it is back together as before, but with some heat shrink on the connections so they won't accidentally short.
 

Attachments

  • 25686.png
    25686.png
    13.8 KB · Views: 117
Sometimes power antennas use relays. Many older radios did not have an output for them. If you have a power ant. you should be able to trace back fairly easy. Just a thought.
 
Sorry, Darrell - not much help there. But I'm sure someone else will pop in with an answer.
 
Well, it is confirmed, the relay is only powering the fog light switch when the low beams are on.

It looks like the fog light switch is supposed to do that anyway, so it isn't clear why this was added, unless that part of the fog light switch failed or something.

-Darrell
 
After checking the schematic. There seems to be no relay in the system.
So maybe a relay is proper?
I find it interesting the way the switch is wired. It has 2 power sources?
The purple which in a 6 is power all the time and the leg from the fuse for the low beam.
Now, I always thought that when you have your single light high beam on that the low still had current through it.
I guess that is not the case Eh?
 
Hi Don,

While a relay is good, this only is wired so that the switch still carries the full load.

I'm not sure what the fog light switch does with the two power sources, I'm guessing the fog light switch is supposed to only power the fogs when there is power on the low beam line (if indeed Triumph wired these to only power the fogs when the low beams are on).

I just don't know what that symbol between the P and UR wires in the switch is supposed to be.

-Darrell
 
DNK said:
That just shows the switch
Click to expand...

OK, so it means as you slide it up, that the first stop connects the rear fog lights (are those a separate light, or part of the standard rear lamps?), and the next stop lights the fronts as well?

If so, it still means that it get power from the low beams, and the purple wire, which is always hot, which doesn't make sense.

I'll have to see if the ROM explains it.
 
Nothing in the ROM.

Another interpretation could be that the green stuff between the two red lines indicates insulation (and in fact, if it really tied both together then the low beams would be on all the time). So the function could be that the first position turns the rear fogs on only if the low beams are on, the second position turn the fronts on anytime.
 
I got this reply on the TR8 mailing list:

<div class="ubbcode-block"><div class="ubbcode-header">Quote:]
In the US, foglights are only supposed to work when the low beam lights are on. As a result of this, a factory service bulletin was issued to Triumph dealers that stated relays should be installed when fitting fog lights as a dealer installed option.
[/QUOTE]

Makes sense, the relay and wiring have obviously been there for some time, though I don't know why the ran the wires down to the footwell to the relay, there is room under the "speaker" cover to have it installed there, where all of the wires connect anyway.
 
Surprise to read that it is a 2 position switch. Didn't know that as I don't have fogs but want to get them.
I will wire mine differently. On as DRL.Off with low beam and back on with high beam
 
DNK said:
Surprise to read that it is a 2 position switch. Didn't know that as I don't have fogs but want to get them.
I will wire mine differently. On as DRL.Off with low beam and back on with high beam
Click to expand...

I don't have the rear light (I don't think, there certainly isn't any separate light).

The DRL idea is interesting. I don't think you even need a switch for what you want to do, use two relays in series, one to power the lights when the ignition is on, the other to cut the circuit when the low beams are on.
 
I have a diagram someone on the list did for me. But would have to dig deep.
The rear light is a UK deal
 
Back
Top