Fusible Links and Maxi Blade fuses | The Z Club of Great Britain
  1. The Z Club relies on the support of it's paid members - join the club or renew your membership here.

Fusible Links and Maxi Blade fuses

Discussion in 'S30 (240Z,260Z,280Z) Electrical' started by Turn & Burn, Mar 25, 2020.

  1. Turn & Burn

    Turn & Burn
    Z Club Member

    Hopefully someone can help with this...
    The fusible link that runs the headlights on the 240z/260z is generally a 50amp link, does this link feed anything else? I can tell it feeds the rear lights, but it doesn’t feed the front sidelights. I don’t have enough of the car assembled to get the full picture of there is more than this. The wiring diagram is just hard work!
    I’m doing a relay conversion on the headlights and was going to do away with the fusible links at the same time and replace them with maxi blades, but if the headlights come off the old circuit and get their own fuse feeds the old circuit will be way over fused on a maxi blade and probably only needs a 20amp normal blade or less.
  2. Rob Gaskin

    Rob Gaskin Treasurer Staff Member Moderator

    Are you talking about the link on the starter motor?

    Today I have removed all my power cabling from my looms and I'm simplifying it and doing away with my Ammeter.

    You should have a large fuse on the Starter and the Alternator (not usually in place). Power from these two sources feed the Fusebox, Ign Switch and Lighting Switch directly (like a ring-main).

    The headlights are fed via the Lighting Switch, then fuse box to each headlight separately. So when the switch is 'on' the power goes to each light and either the Main or Dip beam illuminates depending on the position of the Dipswitch (which feeds the 'ground' to the light bulbs).

    So you have two power feeds going to the headlights (L and R). This is a safety design so that if a fuse blows you don't lose both lights!

    When relaying most people use these feeds together with the 'switched earth' to operate the two relays (M and D). A new power feed it then routed to the lights and they are wired in the conventional way i.e. 'ground' to the common terminal not 'batt' as original circuit!

    Provide the 'new' power via two circuits and fuses not one! This way if a fuse (4 now) blows you lose either main or dip beam but not both! My car was wired with one power fuse to the relay contacts (to save wiring) so if the fuse blew I lost main and dip!
  3. toopy

    Z Club Member

    I think the charge feed from the alternator and another wire is on the 50 amp fusible link, the others are 40 amp, at least that's how mine was and i just replicated it. Ignore the blade fuses, this was initially for the head light re-wiring, but i didn't use it in the end.

    Thinking of changing to this instead in the near future https://www.altecautomotive.co.uk/m...on-box-altfh260158--01-closed-back-5856-p.asp

    Remember thinking about the over fusing issue when i done mine, and then promptly forgot about it.... until now!

  4. Turn & Burn

    Turn & Burn
    Z Club Member

    There are 3 fusible links on mine, one of these is a dedicated fusible link for the lighting, maybe it’s a feature that’s only on the late 260z and not the 240.
    I wondered if this fed anything apart from headlights, having just done another hour on it in the garage I can’t find anything other than the headlights that rely on this link eleven the rear lights don’t appear to be on it. As u say Rob best solution going forward is a separate fuse to each relay, ie dip and main which I will do, but it will render this big link redundant or nearly redundant if it feeds anything else so it needs appropriately re-sized or removed.
  5. Turn & Burn

    Turn & Burn
    Z Club Member

    That’s a tidy solution and the Altec unit looks neat too. I’ve already bought my kit so I’ll have to stick with it though!
  6. Rob Gaskin

    Rob Gaskin Treasurer Staff Member Moderator

    Being a late 260 your power wiring is different to what I described. The 240 runs power all over the place in the dash loom.
  7. toopy

    Z Club Member

    That's exactly what i did, however i didn't like the way the dipped goes off almost completely before the main came on, and besides whats the point of having it that way, the main is hardly any brighter than the dipped!
    I wired it so the feed for the relay on the main beam, is also used to keep the dipped relay energised :D
  8. jonbills

    ZClub Administrator
    Staff Member Moderator

    thats a good idea!
  9. Turn & Burn

    Turn & Burn
    Z Club Member

    I had a look at this, assuming ur still on an H4 bulb I don’t think these are designed to work both filaments simultaneously for extended periods, they may not but there is a good chance of overheating and ending up with a light failure. Funnily enough this just cropped up on Project Binky Ep.26
  10. toopy

    Z Club Member

    Ive read similar since doing it, but came to the conclusion that, for me at least

    1. main beam is rarely used and besides extended night driving using just dipped in the Z is rare, for me.

    2. being able to flash the lights without first losing dipped is so much better.

    3. it's all rewired with fractionally larger gauge wire, relayed and correctly fused.
  11. Turn & Burn

    Turn & Burn
    Z Club Member

    It was the bulbs that I was concerned with rather than the wiring, but can you share the wiring diagram, I can’t figure how to energise both circuits on main but only the dip circuit on dip beam. My circuit design would backfeedto main beam when I’m on dip.
  12. toopy

    Z Club Member

    Yes, i was thinking that too so dug out my notes, I do have a rough wiring diagram of sorts but i did also jot down what i did anyway, although i must admit the memory is hazy on the details, it's always so much clearer when you actually have the wiring in your hands and a multimeter! Also the wiring colours may well be different on yours o_O

    1. Existing Red wire now feeds/energise's the new dipped beam relay, with a new wire to ground (not sure on this, as how is it switched on, unless the live is switched on and off, can't remember, but it all works)

    2. Existing Red with Black trace wire is now redundant, this is the original switched earth for the dipped circuit, but it goes dead (or could be live, can't remember and i didn't write it down) when you use the main or flash, causing the momentary black out which really annoyed me, so i didn't use it.

    3. Existing Red with Yellow trace wire now feeds/energise's the new main beam relay, there is an existing Red with white trace wire that is the original switched earth for the main beam. This is now used as the earth wire for the energise side of the new main beam relay, as when dipped is in use it was/is live so the main stays off, but when you switch main on it is earthed, i presume in the actual column switch, but because of the rewiring in 1. and not using 2. the dipped remains on.

    Im sure i got the basic idea of the above from somewhere online at the time, but i never bookmarked it or printed it out annoyingly!

    Hope that helps in some way...... my brain hurts!

    Attached Files:

    Last edited: Mar 30, 2020 at 10:36 AM

Share This Page