Joseph0284

hey guys, i just bought a 94 z28 with a rebuilt 355 LT1 the other day.For some reason the cooling fans arent turning on at all. I already checked all the fuses and they are all good. These Lt1's are new to me, any and all help is appreciated. Thanks

scorpion_z28

iTrader: (6)

Check the fan wires they might be cut or something,also look for a manual switch it might be there somewhere.

Zralou

iTrader: (3)

Are you sure?, the LT1 doesn't kick the fans on till around 225*, which is way to hot but that's GM's wisdom!.
The easiest way to check if they work: as you sit in the driver seat, under the dash by your right knee is the ALDL port. Place a jumper wire across the 2 top right terminals of the ALDL, then turn the ignition to "ON' but don't start the car, the fans should now operate if everything is ok.
Don't forget to remove the jumper wire before starting the car.

Sara Lou

MadMike 97 Z28

iTrader: (3)

how hot does it get in traffic. as said by some others already the temp gets very hot (around 230) before the fans kick on many people either retune the fans to kick in sooner or they get a manual fan switch. trust me i know its nerve racking but thats how GM designed to run. you could check them by driving the car with the a/c on though as soon as the a/c is switched on it should kick in the fan.

Joseph0284

the fans wont turn on with the ac on at all. and it gets about to the red line on the gauge

infinitebird

iTrader: (11)

there's only a few possibilities really, blown fuse, blown fan relay, bad wiring or electrical connection, bad fans, bad tune or pcm.

MadMike 97 Z28

iTrader: (3)

just to make sure the car does run fine when its not sitting in stop and go correct? cause if its getting hot while driving at constant speeds above 35 and overheating then its not a fan related issue. sorry for the dumb question but some people have been quick to blame fans only to learn later that the car overheats all the time not just stop and go.

if you have a meter and you know its deffinitely a fan problem then get you some wiring diagrams and go to town i would check the relays first they seem to usually be the problem. if you need any more help or dont have a multimeter then let us know.

sorry for the long post

WFW_maro

i put manuel switch for it

ThoR294

iTrader: (6)

is there a way to change at what temp the fans come on, besides a manual switch? or is it always going to be like 80billion degrees?

Next level

iTrader: (5)

i just rewire them to a igition fuse and leave them on all the time. My car has never overheated or caused any issues at all. I was going to spended 80 bucks for a fan switch when i can custom make one. It sounds like you have a bad wiring issue like i did.

MadMike 97 Z28

iTrader: (3)

no no no dont ever do that the fans are only needed when you are going lower than 35mph if you have them on all the time it will prematurely wear out the fans then you will be spending much more than $80 which a switch can be made for like $10. i actually have the SLP switch which cost me like $45 i bought it because i didnt want to have to cut or splice any wires i just wanted it to plug in.

MadMike 97 Z28

iTrader: (3)

yes you can have your PCM retuned but that would cost more than a switch. its one of those things you just automatically get done when you retune your computer for other things.

hyperzone

both temp sensors good? pcm uses the one in the WP. gauge looks at the one in the DS head.

Joseph0284

nah man the fans arent turning on whatsoever at any speed and the car will get hot when i stop. but i am positive they arent turning on and i have considered the manual switch or hard wire approach. i had an iroc a couple years back and i ended up doin that to her. just looking at the LT1 makes me appreciate that L98 lol

Zralou

iTrader: (3)

Jumper terminal 'A' + 'B' on the ALDL (same as getting the trouble codes on your old 3rd gen). Doing this should turn the fans on, if they work then its probably PCM related like mine (PCM only see's 180* when its boiling over). If the fans don't turn on, then its into the wiring, sensors, relays, etc.

Sara Lou

FAD2BLK93

+1 for checking temp sensors.