Ok i can not find an answer to this ANYWHERE >.> so here is my question, I am working on a 89 Iroc with the dual cooling fans, the fan will NOT turn on and the engine will run all the way up to 260. but if i jump pins a and B on the ALDL the primary fan will kick on (not the secondary) there are no codes stored for a coolant tempurature sensor. also the engine runs great for the first few minute of running, but gets progressivly rougher as the car warms up, though i beleive that to be due to a couple of injectors that drop to approx. 10 ohms and lower after warming up. what do you guys think? im going nutd here.

 

I was having the same issue with my 90 GTA. If you check the wiring from the relay, follow the orange wire from the relay down on the LH side of the engine compartment and it should go to a connector which has 2 wires on each side. Check to see all that is intact. If so check the fuse that should be in a fuse holder mounted on the LH side of the upper rad support. If those are both good check the positive cable to the battery as there is a junction on there with a smaller gauge red wire which run to the afformentioned fuse, if eveything is connected and checks out with the test light... then replace the relay . I hope this helps

 

What is ALDL? I have a 88 iroc and my fans have cease to work. Everything is connected and fuses good I'm think its the relay.

 

ALDL is the link under the dash for the scan tool to be plugged in. It oculd be the ECM as well as all orders go through the ECM. I would recommend unplugging the harness from the relay and jumping the power wire to the fan wire and see if your fans come on. If it comes on then you're relay or ECM is the issue

 

before doing that set the a/c to max a/c and look if the fans are running

 

AC is a good idea but if you're AC needs to be charged it won't reach the propper pressure needed to trigger the switch. I had that problem lol

 

that why i said max a/c, the fans don't run on a/c pressure the run constanly while its on max, a previous owner ripped out my a/c and my fans still work on max a/c

 

That's weird. Mine wouldn't work on AC or Max AC and the primary fan kept it form getting hot enough for the fan to kick in. I recharged the AC and tried it again and it worked on Max and regular. Weird. And in the service manual it say must reach 1600 kpa I believe. It doesn;;t say anything about it running always with Max AC. Out of school and i'm still learning lol

 

Th coolant temp switch doesnt turn your fan on, theres a fan switch above the stater screwed in the head close to the #8 spark plug. thats what turns your fan on once it reaches 230 deg, I know thats hot but thats the way it is

 

well bubba is correct, but if you have a single fan setup, like the rs. it will allways run on max ac

 

Yeah i was speakin on dual fan. haha when I replaced the switch in the side of the head i got a pretty nice coolant shower haha

 

yeah that will happen if you never done one before

 

Well I started undoing it and was thinking Hmm, I wonder if this is gonna go block heater style, and by the time the coolant was coming out it was too late lol. All in good fun

 

Got an 88 IROC and my secondary fan isnt coming on. I believe my refrigerant is too low. It doesn't cool at all. I'll find out when I charge it. I replaced that switch in the block on mine thinking it was the problem. I had a feeling coolant was gonna come out so I made sure to keep my face out from underneath it. Glad I did lol. My relays are fine so I just wanted to back you up on the part about the secondary fan not running if you are way too low on A/C charge. Dual fan setup

 

You should see a relay mounted on the passenger fender wall. It's for the secondary (passenger side) fan. There will be a relay just like it on the radiator support bracket. Look below the filler neck of the radiator. Swap those out and see if your fan works. It's unlikely they are both bad.