Results 1 to 10 of 10

Thread: 75 TR6 headlight issue

Discussions of Triumph motor cars

  1. #1
    Freshman Member
    Join Date
    Jul 2012
    Location
    Saint Louis, MO
    Posts
    23
    Thanks Thanks Given 
    4
    Thanks Thanks Received 
    0
    Thanked in
    0 Posts

    75 TR6 headlight issue

    Hi. Five days ago LH headlight is dim. Two days ago LH headlight is bright and fine and test drive. Today cleaned the three connection tabs on the light itself, yet LH headlight is dim again. Any ideas are appreciated.

    Thanks.
    Thanks for sharing your knowledge !!
    1975 TR6 mimosa and black

  2. #2
    Great Pumpkin - R.I.P TR3driver's Avatar
    Join Date
    Aug 2003
    Location
    Sunny So California
    Posts
    19,552
    Thanks Thanks Given 
    8
    Thanks Thanks Received 
    138
    Thanked in
    129 Posts

    Re: 75 TR6 headlight issue

    First thing I would check is where the black (ground) wire is attached to the body. Sorry I don't know offhand where that is on a TR6 but you can probably follow it backwards from the lamp.

    If that doesn't help, try some detective work. For starters, does the problem affect both low and high beam? If so, it almost has to be the ground wire. If not, it's the wire (or connections) for that filament.

    Take the bulb loose but leave the wires attached, then check the voltage right on the headlight pins. Now repeat the test probing the wire terminals (inside the plastic housing). If they are different, the plug is bad.
    Randall
    56 TR3 TS13571L once and future daily driver
    71 Stag LE1473L waiting engine rebuild
    71-72-73 Stag LE2013LBW waiting OD gearbox rebuild

  3. #3
    Freshman Member
    Join Date
    Jul 2012
    Location
    Saint Louis, MO
    Posts
    23
    Thanks Thanks Given 
    4
    Thanks Thanks Received 
    0
    Thanked in
    0 Posts

    Re: 75 TR6 headlight issue

    Thanks Randall. It does indeed effect both the hi and low beam. Both are dim. There are three black wires related to the front light that are joined together under/within a rubber sleeve but I don't yet see where they are grounded to the body.
    Thanks for sharing your knowledge !!
    1975 TR6 mimosa and black

  4. #4
    Jedi Knight RomanH's Avatar
    Join Date
    Aug 2005
    Location
    Chicago
    Posts
    1,022
    Thanks Thanks Given 
    0
    Thanks Thanks Received 
    0
    Thanked in
    0 Posts

    Re: 75 TR6 headlight issue

    The headlight ground is below and in the center of the grill opening. If you have the radiator shroud in place you will need to remove it to gain access. Once you locate the ground point, clean the terminals. Another thing to consider is to add a separate ground wire to each headlight. I have done this and never have had different light intensities ever again.

  5. #5
    Jedi Knight
    Join Date
    Sep 2006
    Location
    Houston,Tx,USA
    Posts
    1,447
    Thanks Thanks Given 
    0
    Thanks Thanks Received 
    4
    Thanked in
    4 Posts

    Re: 75 TR6 headlight issue

    My TR6 right headlamp had issues for several months. It was very intermittent, but seemed every time I drove at night, the right side would go off, usually for short periods of time, often involving bumps in the road. After cleaning all the connectors, and making sure the grounds were clean I was sure I had it corrected. When I tested the lights for state inspection, the right side didn't come on, and I was finally able to find the cause.

    It was a bad bulb.

    Just to possibly save yourself some work, swap the bulbs left to right and see what happens.
    59 TR3A "Butter"

  6. #6
    Freshman Member
    Join Date
    Jul 2012
    Location
    Saint Louis, MO
    Posts
    23
    Thanks Thanks Given 
    4
    Thanks Thanks Received 
    0
    Thanked in
    0 Posts

    Re: 75 TR6 headlight issue

    Thanks Romanti and others for the tip. Removed the radiator shroud and located the spade ground connection. Cleaned the connector and the body tab thoroughly and LH headlight shines bright. Put the shroud back on, and guess what, LH dim. Remove shroud again and determine problem is where the bullet connectors for the ground for each light come together. Cleaned the bullet connectors but tough to clean the female connector encased in the rubber sleeve.
    So used Remanti's solution and snipped off the LH bullet connector and grounded it directly to the body. So far so good.

    Got me wondering - I'll eventually need replacement spade connectors and the rubber encased bullet connectors. What kind do you all recommend and from where.

    Also, somewhat unrelated, what fuses do you recommend. I read somewhere that a 35 amp British fuse is not the same as a 35 amp US fuse. Anything to that?

    Thanks all !!
    Thanks for sharing your knowledge !!
    1975 TR6 mimosa and black

  7. #7
    Great Pumpkin - R.I.P TR3driver's Avatar
    Join Date
    Aug 2003
    Location
    Sunny So California
    Posts
    19,552
    Thanks Thanks Given 
    8
    Thanks Thanks Received 
    138
    Thanked in
    129 Posts

    Re: 75 TR6 headlight issue

    Quote Originally Posted by irishcasey
    Also, somewhat unrelated, what fuses do you recommend. I read somewhere that a 35 amp British fuse is not the same as a 35 amp US fuse. Anything to that?
    Absolutely !!!

    The original Lucas fuses were rated by the current that will cause them to blow "instantly", while modern fuses are rated by the current that they will carry indefinitely. The difference is roughly two to one! So, if you want to use readily available fuses, an AGC 20 or SFE 20 is the nearest equivalent to a Lucas 35. However, they are slightly different in size; so there might be something to be said for buying reproduction Lucas fuses from the usual suspects. (Personally, I use a 20 amp circuit breaker instead.)
    Randall
    56 TR3 TS13571L once and future daily driver
    71 Stag LE1473L waiting engine rebuild
    71-72-73 Stag LE2013LBW waiting OD gearbox rebuild

  8. #8
    Luke Skywalker mrv8q's Avatar
    Join Date
    Jan 2005
    Location
    Los Angeles, CA USA
    Posts
    1,794
    Thanks Thanks Given 
    5
    Thanks Thanks Received 
    4
    Thanked in
    4 Posts

    Re: 75 TR6 headlight issue

    From Randall, via Drew:

    Like so many other things about our Triumphs, the British did things just a little bit different than the Americans, including what the ratings marked on fuses mean. The British Standard that Triumph used rated fuses by the current that was guaranteed to make them blow instantly while the American (and now international) standard rates fuses by the current that they will carry forever. Fuses work on heat, so a small overload may take a long time to build up enough heat to melt the fusible element and blow the fuse. How warm the fuse was to begin with plays a large role too. So the carry rating winds up being quite a bit lower than the blow rating... the difference is roughly 2 to 1!

    So, what this means to you is that, if you elect to use common American standard fuses (Bussman is one maker, there are others) in your Triumph, you need to use a much lower rated fuse than what your Triumph documentation says to use. There have been cases reported where a restored Triumph has caught fire from a short, because someone used American fuses with the Triumph recommended rating marked on them... the short did not blow the fuse but instead set the wiring harness on fire!

    Here is a conversion chart, lifted from a long-ago Bussman fuse catalog:

    Bussman Conversion Chart

    English Type American Standard Replacement
    50 amp AGC 30
    35 amp AGC 25
    30 amp AGC 20
    25 amp AGC 15
    20 amp AGC 10
    10 amp AGC 7 1/2
    5 amp AGC 3
    Personally, I feel even this chart results in fuses rather larger than needed, so for example I use an AGC 20 to replace the original "35 amp" fuse in my TR3A. My conversion chart would go more like :

    Randall's Recommendations

    English Type American Standard Replacement
    50 amp AGC 25
    35 amp AGC 20
    30 amp AGC 15
    25 amp AGC 15
    20 amp AGC 10
    10 amp AGC 5
    5 amp AGC 3
    Tim Buja and Glenn Merrell put on a good visual demonstration of the difference in fuse ratings at VTR this year, where they first put in a "25 amp" Lucas-equivalent fuse and applied enough load to blow it. Then they installed a "25 amp" American fuse and applied the same load. The fuse did not blow, but after just a minute or so the wire started visibly leaking smoke...

    By the way, proper fuses with the correct British markings are available from the usual suspects (Moss, The Roadster Factory, Victoria British, etc.). The British Standard fuses are also a slightly different physical size than American standard fuses, so it's probably best to buy the proper British fuses. American fuses fit in most British fuse holders, but not all of them.

    Randall Young
    October 17, 2005
    Best, Kevin Browne
    '59 TR3A #TS58370L
    Look for Ancient Aliens on The History Channel

  9. #9
    Great Pumpkin - R.I.P TR3driver's Avatar
    Join Date
    Aug 2003
    Location
    Sunny So California
    Posts
    19,552
    Thanks Thanks Given 
    8
    Thanks Thanks Received 
    138
    Thanked in
    129 Posts

    Re: 75 TR6 headlight issue

    Quote Originally Posted by irishcasey
    Got me wondering - I'll eventually need replacement spade connectors and the rubber encased bullet connectors. What kind do you all recommend and from where.
    The bullet sleeves I got from TRF appear to be good quality. The only problem I have with them is that the inner metal sleeve has a tendency to slide around inside the rubber, so it may need to be repositioned after inserting the bullets.

    For spade connectors, my preference is to buy uninsulated crimp versions (Amp is best, but other brands will do), crimp them onto the wire, then solder the wire where it protrudes beyond the crimp. Then insulate with heat shrink tubing as appropriate. Last time I got them from MMC







    Randall
    56 TR3 TS13571L once and future daily driver
    71 Stag LE1473L waiting engine rebuild
    71-72-73 Stag LE2013LBW waiting OD gearbox rebuild

  10. #10
    Obi Wan hondo402000's Avatar
    Join Date
    Mar 2006
    Location
    Charlotte, NC
    Posts
    2,117
    Thanks Thanks Given 
    0
    Thanks Thanks Received 
    3
    Thanked in
    2 Posts

    Re: 75 TR6 headlight issue

    british wiring has the bullets and the sleeves too, they also sell wire by the foot in the correct colors, and they have complete wiring harnesses too,

    Hondo
    It Is What It Is

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •