ALCL diagnostic connector on '94 Cutlass Cierra?

This is a 6 cyl SFI model. I'm trying to figure out how to do a basic diagnostic on this car. I know with Most GM's of the early 90's, you can short the pins A and B of the 12 pin connector under the dash. Then
turn the key on, and the engine light is supposed to blink indicating any error codes.
I found the 12 pin connector. Problem is, only 3 pins actually have wires running to them. There is no connection to the B pin, a nd therefore, no way to short pins A and B
Here is a picture of what I am talking about at.
http://home.tampabay.rr.com/zc/images/ctlass/IMG_0647.jpg
I also found a connector under the hood. This is a 10 pin connector with 9 actual connections.. You can see this one at.
http://home.tampabay.rr.com/zc/images/ctlass/IMG_0650.jpg
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In article

Hybrid system, in between OBD1 and OBD2, found on some 94s and 95s. You'll need a scan tool to extract codes.

Component connector, possibly for the cruise control, definitely NOT a diagnostic connector.
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Thanks for the info! I'm guessing that one of those cheap code readers found in auto parts stores will not work with this system? or am I wrong?
Also, I am trying to verify that the ECM is actually turning on the radiator fan when it is supposed to.. I've ran the car idle for over 20 minutes, and the fan does not come on. The fan does work, however when connected directly to a 12v power source.
Neil Nelson wrote:

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No, they won't work either (they basically are just a jumper for those two pins, and yes, that does mean that they are, in fact, a complete ripoff)..
As far as the fan, what temperature is the gauge getting up to (if it has one)? The fan doesn't generally come on until the temperature is getting close to the overheating range.
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news:_DMfb.19127$, that does mean that they are, in fact, a complete ripoff)..

I would have to agree. My 94 Grand Prix does the samething. If the fan isn't coming on though, I would recommend looking at the relays for the fan, and make sure they aren't bad. Normally using a known good relay is a good test.
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Since the cheap code readers are nothing more than a jumper and a blinking light, you are correct.

If one knows how the cooling fan is controlled, it is easy enough to simulate the conditions under whiich the fan should come on.
If the cooling fan relay is controlled by the ECM according to the coolant sensor voltage, disconnecting the coolant sensor and jumpering the pins will simulate a hot sensor reading and should turn the fan on. (note, this -will- set a coolant sensor trouble code, but will not harm anything)
If the cooling fan relay is controlled via a separate temperature switch/relay not connected to the ECM, grounding the lead to that switch will simulate a hot sender reading and should turn the cooling fan on.
GM cooling fan come on at around 230*F, so idling for 20 minutes is not always sufficient to generate enough engine heat to verify proper operation.
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The temp gauge on the dash has not worked for a long time in this car. (This isn't my car. )
I'm not able to find the Coolant Temp Sensor..
However, if this is not functioning correctly, I should get a "check engine" light on the dash, correct? And if it is working correctly, and I am overheating, I would get a "Temp" light on the dash, right? So if I don't get any lights, it means it should all be functioning correctly.
I did notice one thing.. If i'm using an almost dead battery in this car, the fan comes on as soon as I turn the ignition switch. Is this some sort of fail safe mechanism in case the coolant temp sensor isn't getting enough voltage?
Neil Nelson wrote:

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ahh, the fan did turn on after about 30 minutes.. I just wasn't waiting long enough before..
THanks for all your answers.
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Is water supposed to boil into the secondary tank before the fan stars?
Water was bubbling into there like 2 or 3 minutes before the fan actually turned on. I opened the secondary tank, and the steam almost burned my thumb...
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Are you using straight water in the cooling system? Not a good idea... Anyway, after 23 years of dealing with GM frontwheel drive applications, most if not all of which had at least a 50/50 mixture of antifreeze and water, I'd have to say no, there should be no boiling or bubbling of coolant into the overflow tank prior to the cooling fan turning on.

You could merely have a radiator cap that isn't holding pressure as it should (easily tested), a blown head gasket, a thermostat that isn't opening at the proper temperature, a faulty coolant temperature sender that isn't signaling the fan to come on at the correct temperature.
You should have the problem checked out by a professional to avoid serious mechanical problems and to avoid further chances of personal injury.
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Put a t-bag in there next time. If it's boiling, you'll be toiling, if it's hot, you're not.
Neil Nelson wrote:

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I'm using a 50/50 antifreeze/water mix.
I think I might wire the fan so it turn on when the ignition is on temporarily (preferrably using the fan relay) until it can be taken to professional. I am going to look for the fan relay tomorrow when it is daylight, but just in case I can't find it, where should it be located? There is a line of 3 relays that look the same on the passenger side near the radiator. Also where is the coolant sensor supposed to be located? I dont mean to be asking too many questions, but that's one of the ways I learn. Also, I don't have a book for this car.
Neil Nelson wrote:

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Coolant temp sensor is located right under the throttle body. (If I remember correctly), that tells the computer to turn on the fans.
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Okay. Your original question about "water boiling" into the recovery tank was a bit misleading...

It is one of the three that you see on the PS of the radiator support. To tell which of the three it is, look at the wiring color and compare it to the wiring that goes to the cooling fan. You're looking for fairly fat wire that matches what feeds the fan motor.

Under the throttle body, near the thermostat housing, it's a two wire connector one wire being yellow, the other black. There's nothing you can do to the coolant sensor circuit to make the fan run constant without creating other havoc with the EFI system.

You should get a book. preferrably the factory manual if you're going to attempt repairs or modifications.
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I replaced the coolant temp sensor. Everything fan related seems to be working fine now.. Now I need to fix the temperature gauge, which doesn't move at all.
Again, this is a '94 cutlass ciera V6 VIN M.
I found a few wiring diagrams on the Internet, but none of them had anything to do with the temp gauge.
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Cheap place to start is the coolant temp SENDER. Gauge and computer have different parts for sensing coolant temp, you took care of the computer with the sensor, now it's time to take care of the gauge with the sender...

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230*F ?? Can water even get this hot without antifreeze? This is beyond the normal boiling point of water. Seems a little high to me. What happens without antifreeze?
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In article
snipped-for-privacy@hotmail.com (sempe) wrote:

Cooling systems are pressurized, raising the pressure in the cooling system raises the boiling point of the coolant (even water) considerably.
Besides, who runs straight water in their cooling system?
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Approximately 10/8/03 17:05, sempe uttered for posterity:

230 F is only slightly higher than the normal boiling point at sea level. You could reach that temperature without boiling by simply digging a deep enough hole in Death Valley, or just use any available hot rock style geyser--which is how they work in the first place.
It can also be reached by your grandma's pressure cooker. Or that old steam engine.
Sorry it seems so high, but any physics websearch could give you a pressure/boiling point curve. Boiling occurs when the vapor pressure of the water is the same as the external pressure on the water. With a roughly 30 lb pressure cap, you get a boiling point of about 270 F if I did the math right in my head.
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