TR4 charging issue

[Brian Sculpher]

Hi am wandering if anyone else has suffered a similar issue.

Engine starts quite happily from cold, ammeter indicates charging however within minutes the ammeter reverts to a negative reading.

This is linked to the ignition light which will not show when switching on and off.

The car is left overnight and the following morning the above issue is repeated again - this occurs time after time although a couple of instances when the car was left running for some 10 minutes the ammeter returned to normal charging although briefly.

The alternator was checked by a friend and was considered operational although whilst spraying the alternator with an electrical contact spray the ignition light came on again continuously.

Is there anyone who could advise me - perhaps my alternator is the issue?

Thanks Brian

 

 

[Guest]

Hello Brian,

Is your alternator the ACR type or AC which runs with the 4TR module and own loom etc ??

If ACR, then yes I would say alternator issue; if AC then perhaps one of the three units (including the 4TR) may be at fault. 

With regard to the IWL, did it flicker or pulse on / off in relation to engine revs which is a common fault sign of this type of module playing up. 

I'm not versed with the charging system of a TR4, hence the few questions.

Regards.

Richard.

[poppyman]

Hi Brian, you need to check the output of the alternator with a volt meter, it should read approx 14.8 volts. If it does that it is a wiring issue. But a simple check will save stripping the alternator or buying a new one.

Tony. 

[Brian Sculpher]

Hi thanks for the immediate response however I have limited experience with electrics. Whilst the car was running I checked the output at the battery terminals readings varied from 12.5 to 12.6. Is this check good enough to indicate an alternator fault?

Brian

 

 

[poppyman]

3 minutes ago, Brian Sculpher said:

Hi thanks for the immediate response however I have limited experience with electrics. Whilst the car was running I checked the output at the battery terminals readings varied from 12.5 to 12.6. Is this check good enough to indicate an alternator fault?

Brian

 

 

Hi Brian, It does sound like alternator, bot if you do the same check on the two terminals on the back of the alternator, it would rule out any wiring faults.

Tony. 

[Brian Sculpher]

Hi (classiclife)

Re; alternator type am not sure as was with the car when purchased some 14 years ago. The ammeter goes straight to +30amp on start up, by tapping the unit face it returns to charging around 15amps prior to settling down and returning to a negative charge with ignition light permanently out until next day.

Brian

[Brian Sculpher]

Hi Tony - sounds like the best option checking the current directly out of the back of the alternator terminals.

However being nervous of electrics what would you consider the safest way to connect my positive/negative terminals as the location for direct contact is a little tight.

Brian

[poppyman]

Hi Brian,  You could just disconnect the two wires and make up a couple of new leads giving you extended wire to clamp to. Or if the wires are not insulated just carefully put the probes or clamps from your volt meter direct onto the terminals. You wont get a shock of any sort doing this. (Unless you drop your volt meter into the pulley's)  

Tony.  

[Pete Lewis]

 

if a tap on the case made a change i suspect the brushes have worn down,

 

Pete

[NonMember]

Worn brushes are pretty much top of the list for reasons an alternator (or dynamo) doesn't work right.

[Brian Sculpher]

Hi All - I’d like to thank you all for the replies (my charging issue). The fault has been now confirmed as an alternator failure.

Thank Guys for your assistance in this matter.

Brian (Newbie) Sculpher