Firstly, thanks for popping in, cause these topics are quite frequent I know.

I have this possible issue with my 1100 engine where it looses approximately 400 rpm when I turn the headlights on, to the point where the car sounds like it will stall if left to go longer than 10 seconds.

I replaced the alternator with another exactly the same, but the results were also replicated.

Anyway, If anybody would like to throw ideas into the arena for me to have a gander at
or tell me what I should be making my car idle at all would be appreciated.
Thanks.

400rpm.... Geez thats a lot.

How bright are your lights when u have them on?

Obviously when you have your lights on, your electrical system draws more current, which the alternator has to supply. This loads up the alternator which in turn loads up the motor to due magnetic flux.

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http://www.youtube.com/user/Hanras

The lights are stock rover ones (at low beam), as is the alternator.

Is your car a Rover?

Are they the correct wattage bulbs fitted?

Did this fault just occur out of the blue?

_________________

http://www.youtube.com/user/Hanras

Car is a rover, electrical system is as it left the factory.
Difference is I've just fitted ab 1100 engine to it.
The car's state of tune appears to be okay, however may need the timing adjusted
by a poofteenth of a degree, if that'll help?

Hmm ok... Cant say i know anything about the Rovers wiring system or engine management (if applicable)

Either way 400rpm is a huge drop...

_________________

http://www.youtube.com/user/Hanras

Hi,

What condition is your battery in? Try fully charging it and then do the same test.

Has the pulley size changed on the alternator?

What wattage are the globes?
What output is the alternator?
If you pick up the revs to say 1200 are the lights nice and bright?

just some ideas and things to look at.

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It's not a mini, but still a bloody lot of fun! (and keeps me poor)

Check a couple of connections and make sure they are metal to metal and not metal to paint or metal to rust and corrosion.

They are ;
The negative cable from the battery in the boot.
The earth strap from the gearbox to the body
The power feed on the solenoid.

Give each a quick hit with some emery paper and check to see if the problem still exists.

Mike

my deluxe did exactly the same thing,

i just checked all earths and cleaned up connections.

_________________
-jamie-
1963morris 850
1965 solid side van
1994 rover racecar

I'll check all of them later tonight.
Whilst I'm at it, if I put a little copper grease between metal to metal connections, (with intention of reducing rust/corrosion) will that help or would it be an insulator?
I know copper has good electrical properties, but don't know what else is in the grease.