2003 silverado with 2007 siverado elec fans

[soldierboy]

alright fellas need help recently i damn near totaled my 03 silverado. i got a end from an 07 siverado with, computer, wire harness and fuse boxes for 1200 bucks the 07 front end has electric fans so i figured i would just use those
i did not change the computer or wire harness however i did pull the wires from the computer plugs at the pins and installed them in my stock 03 harness it was a green wire in the blue plug at pin #42 and ablue wire in the green plug at pin # 33 this was a 2 wire plug about 2 ft long from the computer to a plug that goes to the radiator support harness that leads into the smalller fuse box for the electric fan relays any ways the fans dont turn on im wondering if it has to do with the computer programming or lack there of or maybe some type of grounding i missed becaue i unplugged the relay and tried jumper wire and cant get them fans to kick another aspect that puzzles me is there are 3 relays for only 2 fans

[Tdragone]

Holy run on sentence!

To the best of my knowledge; this can be done with one of the tunes like Nelson.. I THINK. Try searching for nelson and electric fan and see what you get.

[soldierboy]

Originally Posted by Tdragone

Holy run on sentence!
lol

Originally Posted by Tdragone

To the best of my knowledge; this can be done with one of the tunes like Nelson.. I THINK. Try searching for nelson and electric fan and see what you get.

thanks ill check it out

[soldierboy]

i went today to a shop first they said they could reprogram my computer to kick them fans on. than they said i needed the computer off the 07 which i provided, neither worked.
so i went home and began going through the harness wire by wire and checked the polarity of the fans and tried to figur out what was going on in the fuse and relay box now am only more confused (one relay, the only 5 prong relay, seems to connect the fans in series wich produces a reduced speed, than connects both postives together when the relay is energized)

i assumed the fans should spin in the direction that would push air towards the radiator. but i couldnt really tell so i drew up my own wiring diagram of how the system and i double and tripled checked. i could only think that it must be wrong.
now where i stand i would like to know if anyone has a wiring diagram for that nelson harnes. and would also like to know at which point the the fans should turn on i thought by reading other informaation on various sites they should turn on in 3 stages sustainment of(low speed or single fan) need to lower temp (high speed) and when the AC is on if any one can provide any technical info plz do so we are to the point where i might just try and track down the clucth fan and shroud and go that route
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[j cAT]

unless you have a larger alternator i would go with the fan/clutch as the original was built.. the electric fans would need control circuits so as to permit proper operation with vehicle speed/hvac/engine temp etc...


having a manual controlled electric fan may be helpfull if you find this is needed at high temps with ac on..

[brcidd]

typically low speed is 6 volts to each fan- wired in series, and high speed is 12v to each fan wired in parrallel-- that is why it takes three relays to do this comversion between series and parrallel circuits

[wally91vhevrolet]

you can buy a kit from autozone for an electric fan and has a temp sensor that you put in the fins of the radiator and this controls when the fans come on. turn on temp is adjustable. also has a wire for the a/c clutch. kit runs about $30 could save you a lot of time. just a suggestion though. my buddy put this in a bronco with an aftermarker fan, works great for his application. could prob be used on your fans too.