88 7mgte auto major electrical prob

MA70-3.0GT · 06-07-2013, 02:56 PM

I wonder how long he had it connected in reverse... long enough & it's possible he could have melted insulation somewhere in the loom causing the problem you now have :/ There's some good wiring diagrams & troubleshooting info here http://www.cygnusx1.net/Supra/Library/TEWD/MK3/

If I get time I'll have a look see later, see what's on that circuit that could cause issues but the fact that the windows work without their fuse & stop when the IGN blows would suggest melted loom to me at the moment...

EDIT-: as the windows stop when the fuse blows, are you sure it is definitely the IGN fuse and not the 7.5A GAUGE that's blowing? I say this because this fuse operates the power window relay amongst other things. If it is GAUGE then the loom may be OK after all & you need to check the circuits related to that fuse instead ( Can't copy/paste them but theyre listed here http://www.cygnusx1.net/Supra/Librar...x?S=Main&P=032 ) Also, as it takes time to blow the fuse I'm led to wonder if it's related to either the ABS or ECT systems, possibly something in their self-test regime that causes the fuse to blow after XX seconds?

06-07-2013, 02:56 PM	#2
MA70-3.0GT 12psi boost Join Date: Oct 2009 Location: Crewe, England Posts: 356	I wonder how long he had it connected in reverse... long enough & it's possible he could have melted insulation somewhere in the loom causing the problem you now have :/ There's some good wiring diagrams & troubleshooting info here http://www.cygnusx1.net/Supra/Library/TEWD/MK3/ If I get time I'll have a look see later, see what's on that circuit that could cause issues but the fact that the windows work without their fuse & stop when the IGN blows would suggest melted loom to me at the moment... EDIT-: as the windows stop when the fuse blows, are you sure it is definitely the IGN fuse and not the 7.5A GAUGE that's blowing? I say this because this fuse operates the power window relay amongst other things. If it is GAUGE then the loom may be OK after all & you need to check the circuits related to that fuse instead ( Can't copy/paste them but theyre listed here http://www.cygnusx1.net/Supra/Librar...x?S=Main&P=032 ) Also, as it takes time to blow the fuse I'm led to wonder if it's related to either the ABS or ECT systems, possibly something in their self-test regime that causes the fuse to blow after XX seconds? __________________ '89 MA70 Supra GT aero 3.0turbo JDM, Rebuilt motor, K&N intake, 3" stainless turbo-back. New turbo and braided line kit... '89 Honda NC27 400, NC23 cams, open pipe, PC36a shock & possibly Showa USD forks... '83 Yamaha 29R XJ750E-II, number 69 off the line, only runner in the country? Original except Koni shocks '95 Honda PC26 CB500R, Winter hack, hateful, trying to sell it I'm not paranoid, they really ARE after me!!! Last edited by MA70-3.0GT; 06-07-2013 at 03:17 PM.