Jump to content

Alternator Drain


Guest bikerdcr

Recommended Posts

Guest bikerdcr

Thought I had this wring cracked....wrong. Engine test stage without dash and stalks connected yet was a massive success. However, battery went flat overnight. Charged it up, thought about taking it back, but checked voltage flows first. Am using alternator with 3 threaded posts. Would asume thick brown to the thick post, other battery wire next to that and third wire to the bottom terminal. Battery shows charging when running. When I take off battery live, with ign off, have 12v flow between battery and live lead. Traced it to the alternator. Have same 12v between both brown wires and the alternator. Is this my drain, or is the new battery shot?

Link to comment
Share on other sites

Guest chris brown
Thought I had this wring cracked....wrong. Engine test stage without dash and stalks connected yet was a massive success. However, battery went flat overnight. Charged it up, thought about taking it back, but checked voltage flows first. Am using alternator with 3 threaded posts. Would asume thick brown to the thick post, other battery wire next to that and third wire to the bottom terminal. Battery shows charging when running. When I take off battery live, with ign off, have 12v flow between battery and live lead. Traced it to the alternator. Have same 12v between both brown wires and the alternator. Is this my drain, or is the new battery shot?

Rather than checking voltage you need to be checking for current flow.

Start at the battery and disconnect the +ve term and with ammeter in series with +ve term and lead check for current flow if there is then disconnect things in turn until you find your fault BTW if the alt you are using is off the Sierra then only two connectors are used, the large one goes direct to battery or battery via starter solenoid and small wire to warning lamp then to switched 12v

Link to comment
Share on other sites

I made the same mistake with a 3 pole alternator on the V8. The 3rd connector is to supply 12 v to the alternator to excite the beast, but is not needed. The alternator self excites at about 3000 revs. If I had wired it through a relay i might have got away with it by dropping of the 12v as soon as the ignition off pos 3..

 

Only 2 wires needed --large browns to battery/starter and blue to ignition bulb.

 

Graham B

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...