C40l dynamo problems

[nicmk1est]

hi all

got up this morning and car wont start,,,flat battery,few hours of charging car running as normal
big terminal on dynamo charging at 14v`ish but small terminal showing missus charge coming out?
should this be normal? ive checked all connections
any ideas anyone?

thanks

[piman]

Hello Nic,

the small terminal is the field terminal and the voltage varies depending on what the regulator is doing. If you are getting 14 or so volts from the main terminal the dynamo is charging.

Ale

[nicmk1est]

hi piman
that means the regulator black box is gone? any way of checking the black box?

[piman]

Hello Nic,

no, if it is charging, which 14v says it is, then the black box is working, I'm just saying you may get variable voltage readings at the dynamo field terminal.

Alec

[nicmk1est]

hi piman
that 14 volts is when ive got 2000rpm,,,on tick over im only getting 6-7volt at around 800rpm,,,check the reg box and that not holding,voltage fluctuates. and on top of that---
the discharge/charge gauge dont go into the charge,,,only in discharge even when everything has been turn of.when engine is off,needle in the middle position,,,when starting and running on tick over it drops into discharge,when the sidelight or main lights is goes half way in to discharge and when you build up rev`s it still stays the same and dont go into charge

[nicmk1est]

think ive just found them problem!!  burn out reg box

[piman]

Hello Nic,

if you had said earlier that your ammeter was always in discharge it would have put a different light on things?
Yes, a new regulator is required :-)

Alec

[nicmk1est]

hi piman
i got there in the end

thanks for all your help :) :)

[nicmk1est]

dynamo and reg box now binned!!!hooray for the alternator :) :)