okay so i got the MSD box wired as i had it on my other GSLSE. No problem. hooked up a switch the the fuel pump. Gave the car power. The top fusible link smokes out. Great. undid the fuel wire, replace link with one from other car. give power, lose link. okay....so....the MSD box is wired EXACTLY as it should be. Could the fusible link be taking too much load with the MSD box switched 12v wire running on it? Everything i did worked on the other car, granted i had a striaght wire instead of a link so there was no fuse really.

thoughts?

 

Yeah, you are probably overloading that link. Is it the top one on the group of three or is it the top one on the group of two. Anyway, I would just run the power to the battery and use an inline fuse if you need a constant source. Check the MSD manual for the proper fuse rating. For a switched (I think what you need), do the same (power with inline fuse) and get a relay to switch the load. The relay could be switched from say the stock trailing coil +.

 

The thick MSD lead wire should be connected straight to the battery or alternator. But be sure to install an in-line 40 amps fuse for safety reasons. My cars have upgraded S4 & S5 alternators with FC fusebox. The MSD lead wire is in the FC fusebox.

 

the thick red is connected to the battery correctly. the wire for the switch 12v signal is comign off the injector fuse which is the top most link.

 

While your doing all that wiring, upgrade to a 2nd gen fuse box. You will love it!

 

+1 on the 2nd gen fuse box.

Something seems strange. I wouldn't think the MSD switched line would cause enough draw to blow out that link. I believe that link is rated around 40A. Double check the wiring and make sure nothing is shorted. I would still consider an inline fuse on both MSD power inputs just to be safe. The 2nd gen fuse box will give you some extra spots, so you could have a fused constant power source from there. You just need to add the swicthed.

 

the thin red wire can be connected directly to the thick black wire that came off the stock leading coil's + terminal OR directly in the trailing's +.

 

but wait, do i have to connect those back to the trailing coil? or can i have it connected to the trailing coil (or leading if you prefer) and not affect the signal reaching the coil. The method i am using now worked fine on the 85 GSLSE. i dont see what change. i took off one car, walked over, put on the other....

 

You connect to the + side. It is just a switched 12v source. The tach signal is on the - side of the coil. It just seems strange that it would be blowing that link unless something was shorted/connected wrong.

 

100% there.