SR20DET 240sx wiring issues

[rwpowell015]

I picked up an sr swapped 240 last week and ran out of time to check everything over before heading to the track yesterday. Couple of issues popped up that I could use some input on as for how best to fix them. Previous owner didn't do the best job with the wiring and it needs a lot of love.

Issue 1: overheating after a couple of runs, fan switch is poorly wired and kept cutting in and out. One of the guys who helped me out suggested running it through a relay as opposed to how it is setup now (pic attached). Would something like this take care of the issue? http://www.enjukuracing.com/products/circuit-sports-electronic-fan-controller.html ...if not can someone go into more detail about the relay setup? Wiring isn't my strong point...

Issue 2: having alternator issues and discovered the wire going to the back of the alternator is sheared clean in half. The alternator tested bad when I tested battery yesterday. How hard is it going to be to fix that wiring going to the back of the alternator? Where should I start with trying to fix this? I see plenty of replacement alternators but nothing about the wiring.

Thanks for the helphttps://uploads.tapatalk-cdn.com/20170521/57c753bfa33ec9603aac66b1809ba8ba.jpghttps://uploads.tapatalk-cdn.com/20170521/f83d17ae7b2f2efd4d31e06cf8a37d7a.jpghttps://uploads.tapatalk-cdn.com/20170521/842a5e944affc436f99a9e2fde3179f8.jpg

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[rwpowell015]

Can the alternator wiring be fixed without having to replace the whole harness?

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[gaz_moose]

that bit of wiring on the alternator is just going to be a ground/earth down to the chassis. have you got a multimeter? if so use it to check for continuity between the alternator and the chassis. although it should work without it as the alternator is earthed through the engine.
is the engine earth strap in decent condition.

you really don't need to spend $125 on a fancy fan controller, I bet you could pay an electrician that to supply/fit a circuit for that.

basically you need to measure the current draw of your fan when it firsts starts and when it is running (use your multimeter) to determine what wire size/ relay /fuse etc.. you need to get.

[rwpowell015]

Thanks for the response, I live in a small town and there's no auto electricians up here that I've been able to find.

No multimeter but I should probably investing in one. Where does the engine earth strap run to?

Sorry, I'm not the most knowledgeable about wiring. Is the earth strap something easy to source and replace?

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[gaz_moose]

an engine earth strap is basically a thick piece of wire that goes from your engine to the chassis. if you think about it the engine is isolated from the chassis by rubber mounts so you need a good piece of wire to complete the electrical circuit between the two. a bit of old jump start cable or battery cable with a bolt down connector at each end, then clean up where your going to bolt it to.

a multimeter is a good tool to own for electrical work probably cost $20

an electric fan circuit is a nice little starter wiring project. I bet you can get a wiring diagram off google images. but first you are going to need to know what current those fans are pulling.

[Kingtal0n]

The fans I like to use, 93-97 Nissan Altima Radiator & Condenser Cooling Fan Assy $75 from ebay


Each one should get it's own relay. At least 40amp each. Track the car? 160*F thermostat and turn fans on right at 180, reading 180 coming out of the engine, off at 168. Keep oil temperature around 205-212*F.