been a lurker here for many years, im a dedicated 405 hasbeen street racer from way back well before midweststreetcars website was around, was a member there years ago, been a member on yellowbullet since chief took the site down. Spent many late saturday nights at sonic drive in on council preparing/locating/doing security detail/etc with the 405 boys when street racing was the real deal out here. Back when we would haul big tire cars into sonic at 2am on trailers...

I own a 70 nova 6.0 ls motor, th400 trans, quickfuel 830 carbed, shitty 12 bolt rearend. Among MANY other cars/trucks/projects/too many to list...

currently working on a 99 sierra 6.0L, 4l60e small tire truck im building, have some questions regarding various efan issues i need to address, hoping for a little guidance for this project, figured it was time to create an account, lurking for the answers i need is not working out lol. anyway, glad tobe here, hopefully i can get some help with things I need, and im sure I have plenty of knowledge I can provide to the board myself for other things.

Thanks,

Jay.

 

Jay, welcome aboard!

What are the efan issues you're having?

 

Well, I bought OE fans/harness/fuse and relay block from an 05+ Silverado. Basically, I'm looking for the absolute best/easiest way to wire this. I've read various threads and seems there is/has been a handful of ways to do this throughout the years, and all of it just has me beyond confused lol.

Not sure if there is a sticky somewhere with maybe a step by step detail for the older 99 pcms or what? I planned on starting my own thread regarding it all, with a list of questions I have. I sometimes wonder if it would be easier for me to just run some toggle switches, with a temp sender as a failsafe backup.

Im probably making it way harder than it actually is... I'm just having trouble following the threads I've found. My brother has HP tuners and should be able to do whatever is necessary, just need to know what is necessary haha. "I'm gonna learn a little tuning through this and eventually get a program to start tuning it myself".

 

https://www.performancetrucks.net/fo...-chevy-484892/

 

I guess I don't understand the need for the extra relay, aftermarket harnesses like the black bear and nelson only have 3 relays to my knowledge, why the additional relay here?

Is this how everyone is doing fans on the older 99 pcm still? Or is there any other ways that don't require the need for the extra relay? It almost makes more sense to me to go with the nelson harness over the factory, simply because it's one less relay to have to deal with, and all the wiring is tight and relays are arranged in a nice neat inline bank. Bad thing is, I already bought the special cover with the relay block access door.

So per those instructions in that writup you posted, where does the blue wire he has coming out of his added relay actually go too? I don't understand which blue wire goes to pin 42, the one from his relay, or the one on the pigtail near the fuse block that terminates on the fan harness "has green and blue wired pigtail from factory fan harness"

 

This pigtail, where exactly does the blue wire and green wire go from this pigtail? Are both used or just one?



and is this where you guys are hooking up your power?