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View Full Version : Pin 36 toasted again.



drifter180
08-06-2006, 01:31 AM
ok after searching it seems like theres a few people that have had this pin on the ecu blow. Now I otasted my first ecu, soldered past it got it to work for about a year. then just 3 weeks ago it really toasted and I wasnt able to repair it. so I got a new ECU and got it all put together, anyways after 3 days tonight it fried in the same spot. I am so frustrated it ridiculous as this is my daily driver. Obviously something is wrong with the harness or something But was looking for some expert advice. It is on a 1991 240sx with a s13sr20det redtop, wiring harness i believe is a converted ka but not sure, got it pre-assembled. I know pin 36 is ign on, but have no idea what could be causing this, I think my electric fan is hooked up to ign on but not sure, it turns on whenever the car is on or key is on acc. anyways any help is so appreciated as I cant afford to keep frying these things thanks in advance.

steve shadows
08-06-2006, 06:51 AM
first of all drop the converted ka wiring harness that sounds like a crap shoot.

get a fresh wiring harness and wire it per heavy throttle etc. problem should be solved.

drifter180
08-06-2006, 04:13 PM
after looking further into it, it is a sr wiring harness,. of course i would love ot throw away this harness but my budget doesnt quite agree with me. Looking to see what others have done to fix this problem as it seems that theres quite a few horror stories about this issue.

janders211
08-06-2006, 04:28 PM
Just a guess, but if you're running fans (a lot of current draw) off of an ECU pin that's just designed to turn on solenoids, and run low draw electronics then that could definitely cook something. On the other hand if you just use that pin to turn on a relay for your fans (not directly power them)- than that is probably not doing harm.

S15xedS13
08-06-2006, 05:07 PM
Good point. Solid state devices don't like hi amperage loads when they are designed for low loads.

drifter180
08-06-2006, 05:19 PM
well after messing with the wires all morning i found that on the f8 to e9 plug by the battery tray, the shop that installed my fan soldered the ignition power, coilpacks power, a orange wire that comes from the harness (still trying to figure out what that is) and the fan power all together. needless to say wont be taking anything there again. where should i rewire my fan to for power i would like to have it so its on whenever the cars on. also does anyone know what that orange wire might be and if it is needed the diagram i have just says to connect the coilpacks power, and ignition power to the ignition power on the plug?

BostonS15
08-06-2006, 06:13 PM
Run it off the battery with a thermostat and a relay.
P.S. It doesn't sound like the harness is causing the problem.

S15xedS13
08-06-2006, 06:47 PM
If the orange wire has continuity to pin 25, it is the exhaust overtemp signal. Definetaly should not be hooked up to +12v.

drifter180
08-06-2006, 09:22 PM
ok so found out that the wire was actually brown, so i believe it was the o2 sensor power which needs to be hooked up to 12 v. reworked the ecu, and hooked the fan and the o2 power up to a switch and then to the battery. havent drove it much but it seems fine. the next few day ill know for sure. so in generel conclusion it had the fan, and the o2 sensor power and coilpacks, and ign on all of the ign on wirre Im guessing all that is what has been frying things.

forcefedS13
08-06-2006, 09:29 PM
Theres a relay under the hood near the battery called EGI pump. Use this for the fans, and splice in a fuse to protect the fans. Easy day. The ACC turns on the relay and turns off when you take the key out, unless you have a turbo timer of course. Works like a charm. I have never had a problem since.

drifter180
08-07-2006, 03:36 AM
OK so after working on re-wiring all day i was driving around and the ecu died on me again. at this point I have no idea what is causing this I checked wiring schematics and everything looked right. could my apexi afc2 be causing this somehow welcom e to any ides. and yes i already know i should just go get another wiring harness but at this point it isnt an option ant help is greatly appreciated at this point.

drifter180
08-08-2006, 01:27 PM
nobody has any advice, at this point just want to get it running again and would like to fix it before i toast another ecu.

janders211
08-08-2006, 04:19 PM
Remove everything you don't need to eliminate them as problem areas, such as the E-fans (or at least don't run them off of the ECU). Remove the S-AFC, and recheck ALL your ECU connections to see if something is shorting out. Remove any crimps, and resolder. Smell the ECU , or take off the lid to make sure everything is seated, and there are no burned out leads.