New alternator and wiring
  • Help
Results 1 to 6 of 6
  1. #1
    Fellow Frogger! badabec's Avatar
    Join Date
    Feb 2012
    Location
    Ongar / England
    Posts
    869

    Default New alternator and wiring

    Hello, I've replaced my external regulator alternator with an internal regulator alternator, a Lucas A127, 70 amps and post terminals (rather than a plug).

    It fits and works OK. I've now decided to change the battery terminals and to fit a heavier duty wire from the alternator to the battery.

    Advertisement


    When I removed the cloth tape from the loom, the main alternator output wire has three other wires crimped to it, hidden under the tape. One is yellow, two are black, they have all been wrapped in modern insulating tape then the cloth layer wrapped on top.

    Question, where do these three permanent live feeds go? Radio? Hazard warning lights? Lights? (I think I may have answered my own question...)

    To get the A127 to fit, I cut off the rear lug, made a spacer to allow the pulleys to line up, then drilled and tapped the casing where it was thickened by the rear lug. The A127 doesn't use a woodruff key for the pulley, so I drilled and tapped the inner pulley groove and used a grub screw. They don't bother with a key, it relies on a very slight taper on the shaft plus bollocking the nut up very tight.

    The original adjuster wouldn't fit, so I used a Mini one, the fixed end on the alternator, the adjuster on the water pump.

  2. #2
    Now go make me a sandwich Hotrodelectric's Avatar
    Join Date
    Nov 2010
    Location
    San Diego, California, USA
    Posts
    3,543

    Icon3

    Quote Originally Posted by badabec View Post
    Hello, I've replaced my external regulator alternator with an internal regulator alternator, a Lucas A127, 70 amps and post terminals (rather than a plug).

    It fits and works OK. I've now decided to change the battery terminals and to fit a heavier duty wire from the alternator to the battery.

    When I removed the cloth tape from the loom, the main alternator output wire has three other wires crimped to it, hidden under the tape. One is yellow, two are black, they have all been wrapped in modern insulating tape then the cloth layer wrapped on top.

    Question, where do these three permanent live feeds go? Radio? Hazard warning lights? Lights? (I think I may have answered my own question...)

    To get the A127 to fit, I cut off the rear lug, made a spacer to allow the pulleys to line up, then drilled and tapped the casing where it was thickened by the rear lug. The A127 doesn't use a woodruff key for the pulley, so I drilled and tapped the inner pulley groove and used a grub screw. They don't bother with a key, it relies on a very slight taper on the shaft plus bollocking the nut up very tight.

    The original adjuster wouldn't fit, so I used a Mini one, the fixed end on the alternator, the adjuster on the water pump.
    The three wires you found- were they applied with a yellow butt connector? The three you're assuming are really good guesses, but wrong on a stock D loom. The black PVC tape gives the game away immediately.

    If the insulation on the wire hasn't started to crumble off yet, I would leave that alone until you're ready to rewire the main. The reason being there are several taps that come away from that 10ga output wire as it travels behind the dash, your lights being one of them. The radio should be coming off the accessory tap ("green" fuse, I think), and IIRC your flashers actually should be taking a power tap from the light power by way of a jumper.

    Now, I am a dumb sumbitch- I don't know if your alternator requires an input from the charge lamp to switch on. If so, it's a very easy mod to make. First, disconnect the battery! Take the 'yellow' EXC wire, and apply that to the post that needs the light. Next, go to the regulator. Connect the yellow 'EXC' and red 'L' coded wires together. The white 'R' wire is disconnected from the alternator and the regulator- that wire is now dead. I do recommend removing the purple 'BOB' from the regulator and tying it away- that is hot with ignition.

    The last thing you'll need to do is find another ground point for your start switch IF your car is not '70-> without a battery mounted solenoid. Basically, if you have a start button or a BVH car, you'll need to do this. You're looking for a pair of wires, either nearly in line with the steering column connected to an open reed switch (BVH) or to a starter button, which normally mounts to the steering pod or the lower dash (pre 1970 BVM), both females, one red sleeve, one brown sleeve. The red one is out to the start solenoid. The brown one needs to now go to a solid ground. The reason is this: on a stock system, the switch finds ground by way of the alt light. The light goes off because the light relay in the regulator has gone off, killing the ground for the starter. It's an anti-repeat feature.

    Most modern alternators work differently- they "see" the voltage differential in the switched on and switched off states. Once that voltage differential is covered, the light goes off for the simple reason that an incandescent bulb requires power and ground to work. Power coming in from both sides of the lamp means no ground path, which means no light.

    OK- now that I gone wildly away from your question. Yes- add another 10ga for a charge line from your new alternator. But unless I were going to go underhood and do a major rework, I would leave those three alone for the time being, seeing as you don't seem to have any complaint about function.

    I'd love to see some pics of the install.
    The measure of your character isn't what you do when people are watching- it's what you do when they aren't watching.

  3. #3
    VIP Sponsor richo's Avatar
    Join Date
    Jan 2006
    Location
    Hobart, the other planet
    Posts
    1,448

    Default

    Quote Originally Posted by Hotrodelectric View Post
    The three wires you found- were they applied with a yellow butt connector? The three you're assuming are really good guesses, but wrong on a stock D loom. The black PVC tape gives the game away immediately.

    Now, I am a dumb sumbitch- I don't know if your alternator requires an input from the charge lamp to switch on. If so, it's a very easy mod to make. First, disconnect the battery! Take the 'yellow' EXC wire, and apply that to the post that needs the light. Next, go to the regulator. Connect the yellow 'EXC' and red 'L' coded wires together. The white 'R' wire is disconnected from the alternator and the regulator- that wire is now dead. I do recommend removing the purple 'BOB' from the regulator and tying it away- that is hot with ignition.



    I'd love to see some pics of the install.
    One thing Bill isn't is a dumb sumbitch. You're a clever cookie and a helpful one too.

    This reply is one of the more clear answers to electrical questions.
    Especially helpful to BVH equipped D owners changing over to modern internally regulated alternators.
    Thanks Bill.

  4. #4
    Now go make me a sandwich Hotrodelectric's Avatar
    Join Date
    Nov 2010
    Location
    San Diego, California, USA
    Posts
    3,543

    Default

    *blushes* Thanks, Richo. Coming from you that means quite a bit.
    The measure of your character isn't what you do when people are watching- it's what you do when they aren't watching.

  5. #5
    Fellow Frogger! badabec's Avatar
    Join Date
    Feb 2012
    Location
    Ongar / England
    Posts
    869

    Default

    Hello, I removed the old alternator lead and cut off the three spurs. All three spurs were joined together and a single lead taken from the connector to the battery. The whole lot has been tidied up and wrapped in rayon loom tape. There isn't a lot to see, it looks much like the old alternator, just no external regulator.
    It is a modern style, two wire alternator, one to the battery, one to the warning light. None of the other wires to the external regulator are used.
    I haven't gone to town polishing it up or painting it. When I retire, in a couple of years, I intend doing a proper 'Greenblood' style restoration.








  6. #6
    Too many posts! JohnW's Avatar
    Join Date
    Jul 2001
    Location
    Perth, WA, Australia
    Posts
    11,301

    Default

    Quote Originally Posted by badabec View Post
    Hello, I removed the old alternator lead and cut off the three spurs. All three spurs were joined together and a single lead taken from the connector to the battery. The whole lot has been tidied up and wrapped in rayon loom tape. There isn't a lot to see, it looks much like the old alternator, just no external regulator. It is a modern style, two wire alternator, one to the battery, one to the warning light. None of the other wires to the external regulator are used. I haven't gone to town polishing it up or painting it. When I retire, in a couple of years, I intend doing a proper 'Greenblood' style restoration.
    When you retire you plan to do what????

    Seriously, as usual I'm blown away by HotrodE's input.
    JohnW

    Renault 4CV 1950 (R1062)
    Renault R8 1965 (R1130)
    Renault Scenic Series II 2005 (wife's)
    Renault Scenic Series II 2006 (daughter's)
    Renault Scenic Series II 2007 (mine)

    CitroŽn CX Pallas 1980 (moved on to new custodian)

    National Co-ordinator, Renault 4CV Register of Australia

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Posting Permissions

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