Clicking/relay when Engine is warm

Discussion in 'Mech Tech' started by 77bay, May 9, 2021.

  1. Trying to figure out why my engine is running rough. Sat idling waiting for it to warm up and when it does the alternator starts to intermittently slow down with a constant clicking noise from this relay/fuse thing.

    Any ideas what this relay is and what’s going on with the alternator?
     

    Attached Files:

  2. Could be a split charge relay. Pull the connection to it off from the alternator light terminal on the alt.

    What do you mean by “alternator slowing down”?
     
    77bay likes this.
  3. Is it a split charge relay for your leisure battery?
     
    77bay likes this.
  4. Started to whine slightly, the best appeared to slow down and the engine began to splutter.
     
  5. If the relay kicks in would the extra load of a partially discharged leisure battery "load" the alternator and slip on a loose fan belt
     
    snotty likes this.
  6. Do you have a leisure battery?
     
  7. Y
    Yep have a leisure battery.

    The belt doesn’t appear loose but the alternator picks up and clicking stops if I increase the revs. Only started to happen as it got warm.
     
  8. 77 Westy

    77 Westy Supporter

    It will run rough if you let it idle to warm up – start it and drive it.

    That looks like a split charge relay (blue wire from the alternator light) and as the engine runs rough and slows the alternator stops charging, warning light comes on and relay clicks off.
     
    77bay likes this.
  9. 77 Westy

    77 Westy Supporter

    What does the ignition warning light do?
     
    77bay likes this.
  10. Was letting it idle to see if I could hear anything and check the timing which seems spot on.
     
  11. Didn’t check that, had my head in the noisy cupboard but will take it for a run tomorrow evening to see. The joys of working on a van alone.
     
  12. Is the ignition/alternator light on the dash going on and off?

    I would disconnect that relay and see what happens. A poss is that the leisure battery is knacked and putting a heavy load in the alt.
     
    77 Westy, Valveandy and 77bay like this.
  13. Go for a bloody good run down some local bypass and then see how it is:)
     
    77 Westy and 77bay like this.

  14. Will try this and test the leisure battery as well. It was only a cheap one I bought a couple of years ago, small enough to fit under the wheel well.

    https://www.batterymegastore.co.uk/product/hankook-65ah-leisure-battery-12v-xv65/
     
  15. Will do, I’ll report back tomorrow evening.
     
    Valveandy likes this.
  16. 77 Westy

    77 Westy Supporter

    Cold engine just making enough revs for the alternator to charge, split charge relay clicks on, load increases to charge the leisure battery, engine slows, alternator stops charging, relay clicks off. And repeat.

    Solution – start engine and drive off.
     
    Iain McAvoy, DubCat, matty and 5 others like this.

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