Need some insight to a issue I'm having. 87 GTA 5.7 TPI dual stock fans. On any day just cruising with AC off it'll stay around 180 with my 160 t-stat. Turn the AC on and it climbs up to about 220-240 gradually but quick. I have a John Wayne chip and for whatever reason with his chip my fans come on as soon as the car starts even if the engine is dead cold. Recently I turned the AC on and observed my fans, they both shut off for a moment around 190 then kicked back on. Also my passenger side temp sensor is unplugged. Both of my fans were wired together by previous owner, but that's never been a issue. Is the chip causing this problem? I only went with him since I saw a lot of talk about it and recently did a auto to manual swap but I've had nothing but headaches from his chips and service. Can anyone point me in the right direction.

 

I never heard of John Wayne,Duke. Dump the chip.

 

I agree with jacksons89. Your secondary fan is probably pulling too much power from the primary, so they both may be running at the equivalent of a single fan.
The switch in your passenger side head closes when A/C is enabled and a certain pressure is reached.
That's when you need the secondary fan's power to keep the engine at operating temps.
You mentioned they turn off for a moment at 190.
If this is ECM influence, it's a bit early, so maybe your gauge is a bit off, unless your chip tells the primary fan to jump on at 190.
Anyway, if you can read your ECM data stream, you can observe if it sends a fan switching signal at that precise moment.
Still shouldn't turn them off, so something in the wiring must be wrong.

 

Each fan is supposed to be on it's own circuit but unless you are having an amp issues, I don't see a problem with how your set up is.

My single fan gets hot with the AC on eventually to the boiling over point if I"m not careful. I went to dual fans to correct this and it's worked, sort of.

It is NOT the chip doing this.

I'd personally go back to the factory wiring set up for the fans but it's always a pain to undo what someone else did because you have to figure it out first.

 

The new chip modifies when the fans turn on. Sounds like he's got both fans wired to the primary circuit. I"m surprised he hasn't burned something up yet with that kind of amp draw.

 

Thanks for the replies. I've had the car for some time now and never had issues with the fans or the car getting hot. When I first got it, fans would come on around 230 or so and immediately brought it back down to normal temp with the stock thermostat. After the chip and a 185 stat, the car never saw temps above 195 because the fans were constantly running. With my stock prom, I have no issues. I'll investigate what was mentioned about the fans but I've never had a problem from them before.

 

You need fans and the harness I have both I pulled out of my 87 IROC I had awhile ago. You're welcome to try it out.

 

My fans are good I'm sure. Just replaced the motor on one. With AC off the temp will hang around 180 all day, it's not until I turn the AC on it creeps up. I'd be interested in the harness though.

 

Let me know, your welcome to it.

 

Seems to be alot of mis-information in this thread.

First and foremost, having both the fans run through the "primary circuit" is not possible with just an EEPROM tuning modification. You have to physically alter the car's wiring.

Second, both the fans running at half speed if drawn through the "primary circuit", isn't factual either. This "Primary circuit" everyone is referring to is limited by nothing more than the gauge of wiring and amp capacity of the fusible links, fuses and relays. If ran through one circuit they both will run at full capacity until something blows (relay or fuse) or melts (wiring or fusible link). The stock thirdgen dual fans don't draw a ton of power also FWIW.

Third, was the car behaving this way before you put the chip in? Because I can tell you for certain there is nothing that can be done inside the tune that will affect the engine's operating temp with the A/C on. You have a whole separate issue such as blocked radiator rows, weak water pump, insufficient airflow and etc.

I can tell you I would have the exact same problem with my car every since I rebuilt the whole missing A/C system myself and the proble m is the crappy stock single fan they used in 85. Without the A/C running I'm at around 180-190 going down the highway. A/C on is 200-210 down the highway. Forget about getting stuck in traffic with it. It will hit 230-240 before I bite the bullet and turn it back off.

Also FWIW I do all my own electrical work and my own tuning.

 

Thanks for the insight. As stated previously both fans were tied together by the previous owner. It was done so well I didn't even notice at first.

In 87 and only 87 each fan operated separately. Driver side from the ECM, passenger from the switch in the passenger side head or if AC turned on to Max/Norm, etc. As of now they are both tied to the ECM side.

This has never been a problem before the chip. It had the stock t-stat and fan switch and the fans would kick on when they hit default values and everything was fine. Although at this time I didn't have AC. Ever since the chip, they turn on immediately after the car starts. I take the chip out, fans return to normal operation. I contacted John (Custom Chips) about this and have 3 chips from him (1 for auto 2 for manual) and they all do the same with the fans.

I need to tap into the ECM and check the actual engine temp with the AC on as I have the digital dash. It could be right around the 210ish mark for all I know since its only 2 notches above the 190 mark when I run AC. On cooler days it'll be around 190 with AC on.

For the record I have a new radiator and water pump.

 

Something is not right is his tune. In this screenshot I loaded up in TunerPro for you as an example, here are the five main variables affecting fan operation.



- Override, which turns the fans on regardless of any other conditions when the CTS exceeds this threshold.
- Engine run to start delay, which is the minimum amount of time that must pass after starting the engine before the fans can turn on.
- MPH disable, which turns the fans off when the vehicle is moving above this speed.
-Minimum run time, the amount of the fan has to run once activated before it can turn back off.

On the right side, you will see the table that affects what temperature the fan turns on and back off at.

Also one last item of interest, there is a flag setting in the BIN labeled "A/CHi". Consulting my EBL manual, this is what it states "A/CHi - Set A/C enable output polarity". Now I am not completely sure what that means, however I do know that the pressure switch contained near the passenger side frame rail in the A/C hard body line (The one that commands the fan ON whenever A/C is switched on) had two differing polarities amongst the years. I think they changed it from normally closed to normally open around 87 or 88.

IF that flag is what tells the ECM what kind of switch your car is equipped with and it is set wrong, it will think the A/C is on 24/7 and command the fans on all the time. Just food for thought. Maybe RBob can chime in on the subject and shed some further light (Try sending him a PM).

As a test, you might be able to unplug that switch and see if it causes the fans to turn off.

Now regarding your temperature issue, remember that all the heat being shed by the condensor has to then pass through the radiator. So the radiator not only has to do the job of cooling the engine, it also has to absorb some of the heat coming off the condensor. You said you redid the A/C in your car. Who did it? Overcharging the system can not only lead to poor performance, it will also generate excessive heat on the high side an in the condensor.

Also one last note regarding the John Wayne chips. I see him post (And I use that word loosely, as the correct term would be spam) alot of the thirdgen facebook groups offering his chip services. I am not speaking in fact, rather than speculation and opinion. Say someone gets their hands on a bin file, a chip burner and a copy of tunerpro. All they have to do is add a few degrees in timing, change the fan temperatures for "performance thermostats" and maybe a custom request here and there...bam! Suddenly everyone is flocking to his doorstep for what they think will add 30HP due to street cred (That is speaking for pocket tuners and custom chips in general) and the guy is making money hand over fist.

UNLESS he is custom tayloring each of these chips to the customer's specific vehicle, a generic tune will do very little for your car. This is coming from a tuner.

 

I've suspected the chip to be the issue of a few things to be honest. Which has been confirmed by taking it out and leaving my stock chip in. had I known then what I know now about his chips, I would have went the other way.

I have no clue how you got to that window where you can see the fan properties. Messed around with TunerPro while connected to my ECM but no luck, I just get the standard engine temp, IAC, etc. How do you get there?

I had the AC done by a trusted shop. I put in a new orfice tube, accumulator, and compressor and also new hi and low pressure switches. Shop pulled a vacuum and put the oil and refrigerant in. On a 90 degree day it'll blow out 40. I've noticed when I first start the car from sitting overnight and next day turn the AC on as soon as I get in, the compressor will continuously cycle on and off until the engine temp gets around 200 or so. Once it's up to temp it stays on. Is this normal operation?

The only reason I have a JW chip now is because I went from auto to manual recently and he claimed he could fix up a chip for me that'll work correctly for the swap and I wanted the fans to come on at lower temps but was stuck with them turning on and staying on. I'd like to remove it to be honest but with my fan harness altered and the fans turning on at stock values, I'm not left with much of a choice. This new chip was supposed to fix problems with the previous ones I got from him and add features like my shift light on my dash but to no avail.

 

UPDATE:

Discovered my air damn was all mangled and folded back and one of my fans weren't bolted to the top mount. On the highway she does around 190 now. I still need to verify the temp when stopped. Once I get my fans working properly I'm sure my temps will be better since they continuously run on the highway and I'm sure that's creating a negative affect. AC blowing nice and cold. I'm satisfied for the moment.

 

When dealing with cooling, it's usually something fairly simple.

 

Once I have a fan harness I think it'll be all good to go.

 

I have a harness if all falls through.