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transformer coil problem

Posted: Mon May 28, 2012 3:17 am
by shuggy
So today i installed a Transformer Bosch Coil as replacement of the GT40R i had on it. Had it idling for 1 min and it cut out. No Spark.

Turns out i fried the coil..

Why?

I have a resistor that comes from the positive side to the yellow black wire, and i have the carby slenoids and the dark blue wire from the electronic module running straight to the positive. I have pink from module and green from tach stright off neg..

This is a standard sigma electronic module dizzy, why did i fry the transformer? Do i need to put the resistor somewhere else?

Thanks guys

Re: transformer coil problem

Posted: Mon May 28, 2012 7:33 am
by davetrees
This might help ? http://www.repcotrade.com.au/go/news/hi ... tion-coils

I don't think you can necessarily assume that a GT40 coil and a transformer coil are just interchangeable. (Remember there are resistor & non-resistor versions of the transformer coils, too ...)

What was the problem that required it to be changed in the first place ?

Re: transformer coil problem

Posted: Mon May 28, 2012 5:35 pm
by geezer101
There are 2 types of Bosch GT40 transformer coils - red for points ignition and black for electronic. If you used a black GT40R/T on your siggie I have no idea why it would fry out :\

Re: transformer coil problem

Posted: Mon May 28, 2012 7:10 pm
by A112H
I have a brand new red one in the shed, I bought it before reading the packet and lost the receipt :(

Re: transformer coil problem

Posted: Tue May 29, 2012 2:41 am
by shuggy
No i had the GT40R in there, and i replaced it with a transfomer one. The newer small one with the nipple not the hole. It fried.

So i swapped it and put the GT40R in and its all sweet.

I put the transformer one in because i was told you get a much stronger spark and i had it lying around. I was also misfiring so was trying to help that.

I read that article, didnt help as doesnt say where the resistor goes. Cant read wiring diagram because galants dont have resistor and siggy wiring isnt right for the galant with the leccy module..

Re: transformer coil problem

Posted: Tue May 29, 2012 10:48 pm
by davetrees
Can't read wiring diagram because galants dont have resistor
Some do ..... the wiring for coil with ballast resistor is shown in the GA/GB workshop manual ... want a scan of it ? PM me your email address

Re: transformer coil problem

Posted: Wed May 30, 2012 3:20 am
by shuggy
I have a GB book i will have a look thanks!

Where should a resistor go in line with in general though? from ignition to coil positive yes?

Re: transformer coil problem

Posted: Wed May 30, 2012 7:26 am
by davetrees
Yes - goes to +ve side of coil BUT remember that :
- wire from "B" position on the ignition switch (black/white) goes through the resistor; and
- wire from the "R" position on the ignition switch goes to the coil side of the resistor (ie. not via the resistor ... resistor is only in place during starting)

GA/GB automatics had a ballast resistor, according to the book. You can of course just ditch the resistor and use a non-resistor-type coil (with points ignition, anyway ... dunno about the electronic setup you have ?).