I've read up quite a bit on this excellent forum, and am learning daily. Still cant really get a handle on what is going on with my 93 sl1. Bought this car for a hundred bucks, clutch was out. Got the new clutch in, then the fuel pump wasnt working. Replaced that, got fuel to the injector, and the injector failed to function. Got that replaced, and the car runs fine. But the cooling fan wont work. Checked the fuses.hot wired the fan motor, it works. Temp. sensor looks to have been replaced, but I bypassed with a paper clip...no fan...swapped relays...no fan...AC on...no fan...Checked the codes...got a 23, plugged in the air temp sensor. And the headlights, or wipers dont work. Wiring looks OK. checked the grounds...Is all this stuff related?

 

0) Have you checked the 30A Cooling Fan and 7.5 A fuses in the UHJB?
0.5) Does your AC actually work (compressor clutch kicks in?) If not, swapping the relays you have does not guarantee a true test b/c if your AC does not engage the clutch, technically you don't know that relay is good when you swap it into the cooling fan circuit. You can of course check at the AC clutch for voltage
1) pull off the ECTS connector. Does it have corrosion on it or traces of green (antifreeze)? If so it needs replacing. More on that later.
2) pull out the ECTS on an ice cold engine. Make sure it is brass tipped.
HOWEVER, just because it is brass tipped does not mean it is necessarily going to change resistance with temp as the PCM is expecting. Aftermarket ECTS s are generic and therefore their calibration of R vs T (the curve) usually doesn't match the OEM GM ECTS which causes problems.

Step A: Measure the resistance across the ECTS w ice cold engine and at operating temp, and report back. Include ambient temp the at the time of measurement.

I would have expected the paper clip short to throw a Code 15 for out of range high, and the fan to run continuously since it should think the engine is VERY VERY hot.

Since neither happened, you need to

STEP B: Check the wiring between the ECTS and the PCM.
For starters, the DC voltage between those two wires (the DC V applied across the ECTS should be 5V. If you find no potential between the two, there is a wiring issue and you must start tracing backwards to find the break.
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I have somewhat but not complete electrical schematics for the 93 and I am willing to help you trace the gremlins as long as you know your way around electrical circuits and are willing to do what I ask of you, which sometimes may seem to make no sense at all.
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Headlights

Have you verified continuity of the bulbs themselves, disconnected from the wiring harnesses? Might they be burned out?

If the bulbs test ok....

There are individual 10A fuses for each in the Underhood Junction Block (UHJB) Check those first.


If blown, have a friend with you when you replace the fuses. When inserted, if they blow immediately with the headlight switch turned off, there is likely a short to ground. If it kills both fuses at the same time, it is likely a short in the headlight switch itself, since it sits electrically between the bulbs and ground, and both bulb circuits are grounded through it.

If the fuses do NOT blow instantly w the switch off, stand in front of the car and see if you can catch any microsecond glimpse of headlight output when your friend turns the headlights on. If both fuses blow instantly, again suspect switch.

If the fuses do NOT blow at all, but the headlights still do not work, then you need to check for voltage at the bulb sockets with the switch on. No voltage with fuse good = wire tracing. Again, I would lean towards a switch issue.
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As for Wipers

1) Have you checked the 25A Wiper fuse (believe it is in the IPJB)?
2) The current feed to the wiper motor shares its upstream feed with the radio . So if your radio works, you can isolate the wiper issue to the wiper circuit.
3) With a good fuse, does the windshield washer pump work when the stick is pulled in? Also, do the wipers work on any setting?

If NEITHER work with a good fuse there are a number of possibilities

--wiper control module bad (controls both washer pump and motor function)
--washer motor and wiper motor bad
--wiring to / from switch bad
--switch itself bad
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Recurring theme seems to involve the multi function switch module (think that is what it's called, don't remember). The wiper controls and the light switch are both a part of this one large module that can be replaced if problems are traced to it. If you're lucky it is a loose wiring connection at the harness where it leaves the module.

 

I checked all the fuses and all are good. The AC does not work, and there is no voltage there.The Ects connector is clean, and 5v at the connector. 5k ohm across the sensor cold, ill have to check it hot, it is 70 f. now. Here again, it seems like the fan would kick on with jumping the connector?
Fuses are all good for headlights, I pulled a bulb, and put 12v to it and it works...as do the running lights. The voltage at the connector...both terminals are showing 12v...what's up with that?

Wiper fuse good..nothing works with the wipers...

I am wondering about the ignition switch...Previous owner did not have original key, but found a different Saturn key that works...could they have broken something in the switch, perhaps? That seems like it could be a possibility, with all these power issues...And maybe it's just the multi function switch, with unrelated cooling fan issues...I do have a gut feeling that these items are probably related, though, dont you?

 

Cooling fan:

Really need the operating temp resistance of the ECTS to fully figure out what PCM MAY be seeing when connected up. I agree that jumping the connector should kick on the fan UNLESS there is another sizeable unexpected resistance in that circuit, and your jumpering of that connector decreases the overall circuit resistance by a negligible amount.

When the resistance drops below a preset value in the PCM, it triggers a request for the PCM terminal that is part of the cooling fan circuit to be grounded, thus completing the circuit electrically, the cooling fan relay closes, and current is passed to the cooling fan.

Same thing for the A/C regarding the cooling fan. Request for cooling grounds both the terminals on the PCM for the cooling fan and the A/C.

I may have misstated the expected result for V at the A/C clutch w out AC on. I'll double check on that (sorry)


Wipers
I know you stated nothing works, but is there any V on either of the WIPER fuse terminals (each measured to ground) or the white wire which heads into the wiper/washer pump control module?

Headlights

Check all headlight sockets and see if they are all at 12V on both wires. Based on your finding and the schematics, they should be.

If 12V is on both leads, there is obviously no potential difference so no current will flow. More importantly, it seems to imply that there is a 12V line somewhere feeding the ground wire to that circuit such that the ground is being held at 12V, which could only happen if the other end of that circuit has physically lost its ground connection. Note that this would not have blown a fuse if the ground connection came off while the lights were off.

If you trace it back to the light switch, then you know that requires replacement of the multifunction switch -- meaning we can defer the wiper diagnosis until after replacement.

Out of curiosity I will check and see if they (light switch and wiper switch) share the same ground that may have become lifted.

EDIT: The wiper motor, wiper switch, and headlamp switch all share and I/P ground at a splice pack. However, I cannot tell physically WHERE they come together, and whether the two come together and then lead to the splice pack ground, meaning they both could lose their connection to ground and be held at 12V.
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Many older S cars suffer from overheated, melted, and/or damaged IP fuse and/or underhood junction boxes. Some damage leads to crossed circuits, other damage leads to open circuits, including relays that remain open when they should be closed

i would hold off on it until we are led there, but sooner or later we may need to examine the IP fuse box and check the male and female connections for signs of damage. then do the same for the UHJB, which is a chore (never did it personally), but there is alot going on under there and I have had many independent mechanics tell me that the fuse boxes are a weak point for the S cars.
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How many miles on it? I will guess 290K

 

Made some progress today. The car came with an extra ignition switch, with correct key, so I installed that. The switch is held onto the column with a couple of bolts with small round heads. I took my dremel and cut a slot in the top of them, and used a screwdriver to remove them, they werent as tight as I had figured they would be. All the connectors looked clean. When I got it back together, the lights still didnt work, but in goofing around with the switch, they began to, intermittently, and then after cycling the switch over and over, they began to work correctly. This car has been sitting for at least six years, and I dont know for how long, with the drivers window halfway down. Obviously, the contacts in the switch were a bit corroded, and just needed some exercise...
I pulled the cowl, to get at the wiper motor. I took off the hood to make it easier. I was not having any success getting the connector loose from the motor to check the voltage, so out of curiousity, I turned the wipers on, and tapped the wiper motor with the handle of my screwdriver....Bam...wipers now working at all speeds, squirter too....here again, from sitting in a damp environment, brushes just got a little green, I guess.
Still having issues with the cooling fan. Checked the resistance at the temp sensor at 3/4 guage hot, and got a reading of about 775, and climbed to about 800 with engine off. There is no voltage at the AC, with the switch on or off. I'm feeling better about this car...it has 160 k, so engine wise, it should be good to go for a while, if I get these issues pounded out...it still needs a muffler, some body fasteners, and a good cleaning, but I am encouraged

 

Good to hear!

In all seriousness, it would have helped to know this was a 6 yr + waterlogged vehicle.
Not that I didn't suspect some corrosion in the switches for the headlights and wipers, but when you're talking that level of corrosion, it obviously can drastically affect the behavior of electrical circuits more than just a couple of terminal sweeps can clean up.

Ignition Switch

The ignition switch itself MAY have had corrosion built up such that all switched connections were not making contact and completing their circuits. By replacing with one that had not been rained on every 3rd day and sweeping the contacts clean as you did, you may have restored its full functionality. The question is why was it replaced in the first place? Watch out for key getting stuck or hanging up. If it does and you can get it out, and you INSIST on using the original, take the title and registration to a GM dealer and get at least 1 brand new key cut from the VIN NOT the worn key you come in with.

My guess is that the orig owner had key hangup issues or possibly a stuck key and had to pull it. If you get a new VIN cut key in there soon enough, it should work ok if the cyl is not too worn or internally corroded. Only real way to find out is with a brand new VIN cut key, a generous amount of graphite powder, and time. I am amazed at the ability of graphite powder to change the behavior of a lock that will barely turn or let go of the key to one that feels as though it only has a few years' use on it.

It's a toss up; it's 23 yrs old. You do have the option of buying an OEM ignition switch and cyl from GM dealership if one can be found (if you get one online they should be willing to do it) and either disassembling the original to get the tumbler sequence or paying them to key the blank one to the VIN.

I can't remember if it was 93 or 94 that was the year that the saturn s series car was in the top 5 or ten of stolen vehicles because the cylinders were wearing prematurely and car thieves found it easy to use wiggle keys or screwdrivers to just unlock it, start it, and drive away.

Wipers

I guess you indirectly answered my question regarding whether there was V on either side of the wiper fuse by freeing up the motor. I'm surprised that fuse hadn't blown, as a motor trying to move Mount Everest usually pops the fuse. Maybe it flat out was not getting enough current through the corrosion to do so.

Headlights

Well, I guess the corrosion was the culprit in causing that ground to be lifted in the headlight switch and crossed with the 12V. Have personally never seen that before.

Now I have.
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So all issues with the multi function switch have been worked out? Turn signals? High beams, hazards. etc?

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ECTS (more to come)

 

Well, the extra ignition switch had been pulled from a donor car, I guess, because the original key had got lost. The trunk key from that lockset worked in the ignition in the car, if you put it in there right...I don't think my replacement of the ignition switch fixed the problem with the headlights, though...The switch just needed some exercise...There was quite a build up of debris by the uhjb, so I may pull that unit and see what I can see underneath there today to help eliminate that as the culprit to my cooling fan failure. Do you know if there should be voltage at the HI/lo AC switch? there is none

 

HVAC

Power to the entire HVAC system comes from the batt through a 30A IGN3 fuse in the UHJB. It splits into three branches where it exits the UHJB. Branch A, B , and C. A has 2 sub branches, 1 and 2, B has a single branch, and C has one branch.

Branch A
Sub Branch 1

From there the wiring travels to the ignition switch, where in ACC or RUN position, the ign switch contacts are closed, permitting current through to the IPJB. It splits within the IPJB with one leg going to the 15A HVAC fuse in the IPJB. This is the fuse for the HVAC Module (including the HVAC Module which includes the HVAC Fan switch and blower motor and relay , but NOT the AC Control relay and AC clutch. (that's branch 2).

There is what I believe to be a brown wire entering the HVAC module (ink on the printed schematic has bled and is blurred). This goes directly into the HVAC fan switch.

So yes, I would expect 12V at this brown input wire with nothing turned on. If not there, there is a wiring or fuse issue (possible corroded fuse socket needing sweeping, burnt connection underneath the fuse box, etc.

Branch A
Sub Branch 2

Wiring splits where it first enters the IPJB and is fused thru a 7.5A iGN3 Fuse in the IPJB. Wiring then goes into the resistive portion of the . It then goes to the resistive element within the AC control relay and back to the PCM.


Branch C
It runs from batt thru 7.5 A AC fuse in UHJB, through capacitive portion of AC control relay, through the hi temp cutout switch and to the AC Clutch.

Branch B

Branch B leaves the underhood junction box after the 30A IGN 3 fuse and runs to the IPJB which feeds part of the blower relay. (***The HVAC module resistor pack output and the HVAC switch settings except HI and the HVAC switch HI settings feed into the Blower Relay**** I did not mention this earlier b/c it would have been confusing to point to modules I wasn't going to immediately discuss. The high setting runs thru the resistive portion of the blower. The other inputs mentioned above route to two different capacitive elements in the relay. They are in parallel so the signal goes through just one or the parallel combo of both. The output of the capacitive branch then feeds the blower motor.

Damn that was not fun. Messy circuit as drawn across three pages. But I like helping people and I figured if you had more than one issue with the AC you'd want the rest of the info anyway.

Now that pesky ECTS......

 

ECTS temp turn on is 221 deg F. Should turn on at 3/4 to beginn of red. Your 775 Ohm reading corresponds to 140 deg F which does not sound right at all. Keep in mind your thermostat is a 180 deg F I believe, so if it isn't even open ( I find that hard to believe) there would be no flow in the head, so your temp reading would be a little suspect.

Maybe your thermostat is stuck closed.....

Either way the ECTS (2 wire device) and connector should probably be replaced. Be advised that the 93 has two temp sensors. The one wire device in the head drives the temp gauge , the two wire device is used by the PCM to determine coolant temp. You want to replace the 2 wire ECTS w GM sourced ECTS and connector. This way the PCM is getting as accurate data as possible.

You prob want to search for power at the AC and Fan relays. The ac not turning on the fan is troublesome but may just be a bad ground ---maybe the relay sockets and relay terminals need some sweeping.

Need to go. Will look up rest of ects circuit late tonight if I can

 

Solved the cooling fan issue. Was tracing the wire loom from the AC, again, and noticed a ground junction block, taped to the harness and somewhat hidden. It's right behind the right headlight. Checked continuity and the big wire on the end was dead. You have to have a real small screwdriver or similar to poke into the business end of the terminal to release it out of the block. Sandblasted both connections, plugged it back in,,,and viola. I knew it was going to work when I paper clipped the pcm and the fan kicked on. Took it for a drive, let it sit idling at home for a while...about 3/4 on the temp guage...the fan kicked in...sweet...I love it when a plan comes together. Thanks for your help, Derf...it kept me on task.

ThE AC is probably out of freon, which I assume would render the system dead. I did hot wire the ac clutch, and it works. Thanks again here, for the great AC info!! Hope this post helps others in need...