The 'E' Type Forum

Hi Everyone

I've been reading this topic on alternative alternator options:-

viewtopic.php?t=6668

I've never been happy with the charging circuitry of my car right from day one of ownership. In my many attempts to cure this I've changed every component, even the ammeter but to no avail. The ammeter still bounces wildy about and the needle often disappears past the +30A point when the revs build. I strongly suspect the 4TR regulator is the culprit and initially thought of solving this by fitting a modern alternator with an integral regulator.
I've now decided to investigate a modern replacement for the 4TR itself, or more accurately change the internals for an electronic unit.
Ebay has umpteen for sale but the one I was interested in was this:-

http://www.ebay.co.uk/itm/Voltage-Regul ... Swg3FUgESo

I see from the the images that it appears to have no less than six wires coming out of it instead of the three from the 4TR. Has anyone attempted this before and if so which unit would fit into the 4TR casing?

Cheers

Alan

The 4 TR is elecronic. Trouble is it uses 1970s electronics. Basically monitors the battery voltage and uses this to regulate the current fed to the alternator field coils and thus regulate the charge delivered to the battery. The one you have seen would probably need some figuring to get to work given it has/needs six connections. No reason why a 4TR circuits could not be developed using modern electronics....the 4R circuits is readily available and dead simple. I built an electronic version of an RB340 box for a dynamo for the same reason....the mechanical RB340.....or at least the modern repro ones....are rubbish.

Julian

Make that 1960's electronics- basic to say the least! This particular item interests me because it appears to be compact and made by Durite who I've used before. I'm hoping it comes with a wiring diagram.

Cheers

Alan

Hi Alan....the Jag maint manual has a circuit diagram for the intetnals of tne 4tr...sorry tried to paste it but cant.. may be of help if hou can get a diag of the one you have....but dont think the internal components will be much different

Thanks Steve

I've checked it out in the manual and it will come in very useful. I've also been told that the Durite unit comes complete with a wiring diagram so hopefully I can marry the two up. I'll post an update once I've tried it out. Fingers crossed.
In the meantime I've discovered that my ignition warning light is controlled by the oil pressure switch alone. No 3AW relay involved. The clue was no wire from the AL post on the alternator. Every day's a school day here.

Cheers

Alan