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Glow Plug circuit dropping resistor mod 6v to 12v system

Posted: Mon Oct 31, 2011 8:59 am
by Artie Fufkin
Have observed many referring to modding their 6v system to 12v by wiring in a manual switch and bypassing the glow plug control circuit and of course installing 12 volt plugs.

Correct me if I'm wrong but my understanding is in the 6v system the glow plugs are first "super heated" by being hit once with 12 volts. (12v/6v is reason for there being 2 relays in GP circuit). Then the glow plugs are hit on/off (hence the relay clicking) with 6 volts until the sensor senses the correct operating temperature and shuts the glow plug circuit off.

In theory, since the 6 volts is created via the 150 ohm dropping resistor could you not rip out the dropping resistor and place a jumper there? Then you could install 12 volt glow plugs and you now have a 12 volt glow plug system without bypassing your controller and manual switch addition?

Artie

Re: Glow Plug circuit dropping resistor mod 6v to 12v system

Posted: Mon Oct 31, 2011 10:14 am
by jessef
You can but you're adding an additional failure point in a starting system that is critical in the winter. Something to consider.

Re: Glow Plug circuit dropping resistor mod 6v to 12v system

Posted: Mon Oct 31, 2011 10:48 am
by TardisDeli
Hmmmm, you are A very brave guinea pig to test such an unusual mod.

Especially in a town where you don't have dozens of helpful handy Delica owners and specialist repair shops. Before you press the switch, ensure you have replacement parts: 4 new glow plugs; a rebuilt motherboard; new relays; replacement wire and fuses; and maybe a spare engine because we have all seen the demonstration result at CVI when a heated glow plug metal end breaks off and drops into the engine cylinder and then the piston instantly welds it to the cylinder. Fiasco.

The World According to Christine: a team of highly trained Mitsu engineers spent many an hour with Sake and Schematics designing our BeLoved Beasts, then we of the Red Green School of Mechanics spend many an hour with Cans of Canadian and the Canadian Tire Catalogue.

Christine

Re: Glow Plug circuit dropping resistor mod 6v to 12v system

Posted: Mon Oct 31, 2011 12:31 pm
by Artie Fufkin
Oh I haven't done or tested this guys, just an active mind and an electronics background. Wondering if anyone else had done such a thing.

Artie

Re: Glow Plug circuit dropping resistor mod 6v to 12v system

Posted: Wed Nov 02, 2011 11:23 am
by Artie Fufkin
Just realized the fatal flaw with my idea ..

The control circuit would not be able to "see" the correct resistance with the 12 volt glow plugs to work.

AF