93 Century 3300 Radiator Fan Not Turning / Fuel Gauge Flux / No Cruise Control

[BxOutkast2009]

Greetings All!

Owner of a 1993 Century Special with a few problems, mostly cosmetic, but of course engine problem...but hey, for $100, its still money well spent (my insurance with full coverage is frickin GREAT!...:D)

PROBLEM #1: The radiator fan has not been working since brought...Not the biggest concern because of the damn cold (below 15 degrees Fahrenheit right now) but no sense in pushing towards a total engine rebuild. I've replaced the fan relay on the left hand side near the fuel EVAP canister, but no luck. I asked at least 2 mechanics and they suggested that its more likely the sensor than the fan motor itself (i was ready to swap the whole damn thing out, still am if its Worst Case Scenario here)..

...thing is I cant FIND the damn sensor! I have a subscription of ALLDATA, and I have access to a Chilton paper manual at the library (dont forget folks, your TAXES are paying for that $20 book, better use it, LOL) and the Chilton online manual that I found on here from this site (BIG H/T to Cutlass, you are my HERO for that link), but no luck.

I was told to basically cut the leads to the fan and jump the power to it to see if the motor turns if so its the fan, if not, then the motor. I just figured it would be easier to to the sensor first before cutting and splicing anything unless needed...

So its either the Fan Sensor, The Fan Motor, the Thermostat (?) or the ECM?

Problem #2: I had to replace the Instrument cluster because the servo motor on the speedometer was dead, so no speed gauge (which made driving most days...fun, NOT). On both the original AND the replacement, the fuel gauge seems to jump back n forth a little as much as 2-3 gallon from the actual reading...especially when I'm accelerating or braking. When Idle or car is off it seems perfectly fine. I had also replaced the fuel pump relay (same location as the fan relay from problem #1) and Im praying its not the damn fuel pump.

Could this be a vacuum problem or something simple like a clogged fuel filter or bad O2 sensor or also bad ECM?

Problem #3 Cruise Control is shot. I turn it on, get the green CRUISE light, hit the button on the stalk and NADA, drops speed...sigh

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Things is, especially for this car (which was a lot like my old LeBaron 4-Banger) is that a majority of the work I can do myself, which saves me A LOT of $$$ for the stuff i can't do (lack of air tools/experience/safety)...I rather save money on Labor to do this kinda small stuff, and THEN go to the garage to have my brakes & shocks and struts done....and buy new rims & tires...:D...Hell I was even thinking Maaco for rust spot removal and paint job!


OVERALL the car still runs amazingly well! For a 18 year old engine (still the original) with 185k on the clock, it runs well, and i get the added pep of a V6 that runs on regular gas, AND has plenty of room for 4!

....Now, if ONLY GM didn't put that damned Las Vegas pimp-red interior inside, I'd be VERY pleased indeed...LMAO..ah well, Carpet swap will be the next step...!:cheers:

[CieraSL92]

On the radiator fan issue: Look underneath the dash near where your right knee is-you should see a diagnostic connector and a cover over it that says just that. Jump the top two right terminals to each other (A and B) and turn on the ignition (do not start), the SES light will begin to blink codes, and the ECM should start running the engine fan. If the fan comes on this way, it's probably the Coolant temp sensor. If not it's the wiring or a relay between the ECM and the fan, or a bad fan motor. If it doesn't come on in diagnostic mode, leave the key on with the pins jumped and move around the fan motor harness a bit-mine was worn and would come on in a specfiic position until I replaced it. This engine only has two temp sensors-One for the gauge, and the other for the ECM. They are both located behind the alt on the intake manifold.

The erratic gas gauge issue-I have no idea, I had on mine and I put a new pump and sending unit in it and it didn't do anything to alleviate the problem. It never caused driveability issues, and was mostly still accurate on flat ground so I didn't bother with it

[SilentWing]

On the fuel gauge issue, it likely has nothing to do with the pump. It could be the sending unit, but seeing as though it only does it during acceleration and braking most likely there's a wire under the hood that gives signal to the speedometer that's touching ground or broken in some way. Unless it's irritating you to the point where you want to try and find it and fix it, you could probably just let that one be as long as you still are able to read at idle how much gas is in it.

I'm not sure about the cruise control on the 3300, on my 94 with the 3100 thee's a cruise module in the form of a black box near the drivers side strut tower under the hood. My cruise control never worked either, but in my case it's because the cable under the hood was shot. You can try tracing the cables from the cruise module under the hood (assuming you have the same setup as mine) to see if any of them are frayed or stretched out.

[BxOutkast2009]

Just a quick reply/update...and a grateful thank you to the fast posts so far...

CieraSL92: I pulled the codes for the engine...Only getting codes 26: Quad-driver sense voltage shows a low voltage when battery voltage should be present or if the sense voltage shows battery voltage when a low voltage should be present.. Didn't hear the fan come on in diagnostic mode, so I will assume it is the motor (luckily, Advance Auto only charges $25 w/warranty or i can probably get a yard pull for half that. Will continue to try the wiring, and hope for best...

SilentWing: I will live with the gauge..at the very least, agreed its only a mild irritant in the long run...But since i'll be under the hood in that area looking at/for the cruise control, maybe i'll get lucky; if i need to i'll try to get a yard part for this also...maybe at the very least, i can take a toothbrush to the grimy areas...lol

Will Update on findings and results...pictures maybe if it warms up to freezing...LOL

[SilentWing]

I'm not saying this is for certain and maybe someone else can confirm but any GM we've run across with a quad-driver failure of any kind in the end has needed a computer. The quad-drivers are the actual transistors inside the computer that drive different relays and solenoids, so if you get a code more than likely one of them is going out. You might want to go ahead and jumper the fan motor to battery power and see if it spins before you go putting a motor in it. You'll probably be able to take the connector off of the motor and use a couple of alligator clips and heavy gauge jumper wires (not the thin ones) to get it to battery power. You don't have to cut the wires this way, and if it spins it's more than likely a computer since you've already checked the relays.
Also I'm not sure if this is the case on our cars, but on certain models of GM's they grounded the power for the cruise control module through the third brake light. If the third brake light was out on the cars where GM did this then the cruise control module wouldn't work. I had brain farted on this earlier until my fiance reminded me.

[Pontiac6ksteawd]

No need to hotwire the cooling fan. Putting the paperclip into his ALDL port will activate his relay for his cooling fan, as well as flash his check engine codes.

[SilentWing]

I agree that this is usually a good test, but if the computer is going bad and the quad-driver for the fan motor relay is shot, regardless of ALDL port activation it still wouldn't activate the relay. I was just letting him know how to verify whether or not the actual fan motor itself works since he was going to go ahead and buy a new one.

[BxOutkast2009]

Well, from all the above mentioned fixes, i did the port test, got code 26 only, and i tried tracing the wiring back..no dice. So instead of hunting for sensor or fiddiling with the fan motor, im going to try to swap out the ECM. I have a few yards from me that have them in stock, and between that and Ebay, it about $25. If that doesnt work, its okay...I got a spare ECM...

Like I said, I like the car for the majority of fixes can be done with a minimum of fuss...I used to have a 85 Lebaron Turbo Hatchback...4 cyclinder but the damn thing would not die as long as you tweaked it right with just a few wrenches and diagrams...If i can find the money to do a proper repaint job and rally get rid of some of the rusting from the underside and such, i think i can get to 300k without a major rebuild...and for less than $500 in insurance? Hell yeah!

[Pontiac6ksteawd]

Dont forget to swap the EEPROM from your old computer, to your new computer.

[Prospeeder]

Im gonna go with bad fan motor. Iv replaced the one in my 6000 and my Ciera

[mechanizeddeath]

I thought the swinging fuel gauge was normal for these cars? Mine does it, and I seem to remember every A-body I've ever been in doing it as well.

[SilentWing]

The fuel gauge really depends, when I first read the post I thought he meant it was changing very quickly. I haven't had the full gauge cluster in long enough to watch the fuel gauge to see if it still moves as much as the stock one did, but I know in my stock gauge under acceleration and braking the needle wouldn't twitch, but it would move back and forth quite a bit. It took me a while to get used to that when I first got it, because I was always paranoid something was wrong.

[Prospeeder]

i think its normal for the gas gauge to swing around like crazy, my 6000, Ciera, Grand Prix, dads silverado and suburban all do it. If its too extreme its posible the baffles in the tank somehow broke and the gas is just sloshing around

[BxOutkast2009]

Okay as another quick update...

Placed an order to get another ECM, via Ebay $30...as I stated before, if for no other reason, I'll have an important spare just for a rainy day.

While underneth the hood, I had again jumped the dataport to diagnostic mode and listened for the fan as well as watched for any movement...Nothing...

...But i did hear a repeated 'clicking' sound from the vicinity of a small black box device that's mounted next the air-box on the 3.3l engine...offhand, I'm not sure what the device is for and forgive me for the lack of pictures, but i didn't have the camera phone handy at the time. I'm checking the manuals from both ALLDATA and Chilton for descriptions...

[lemons bob]

Did you try turning on the ac. If you turn on the ac it should automatically turn the fan.

[SilentWing]

Does the black box you're talking about look anything like this?
http://i618.photobucket.com/albums/tt270/SilentWing/cruisemodule.jpg

That's my cruise module, the one the air filter is "pointing" to by the strut tower. Keep in mind though that mine is a 94 Ciera with the 3100 and I'm not sure what the module in your Century would look like. I'd assume with the only one year age difference though that the box could be what you're talking about. As far as the clicking I'm sure someone can say all of the things it could be, unfortunately I have no idea ATM.

[Prospeeder]

Easiest way to test the fan, pull it out, 4 10mm, and then use some jumper wires from the battery and see if it comes on, thats what i do fast test. Iv seen a few chryslers with no fan operation and the ECU wasnt suppplying the ground for the relay, replcment of the ECM solved the problem.

[mechanizeddeath]

Does the black box you're talking about look anything like this?

That's my cruise module, the one the air filter is "pointing" to by the strut tower. Keep in mind though that mine is a 94 Ciera with the 3100 and I'm not sure what the module in your Century would look like. I'd assume with the only one year age difference though that the box could be what you're talking about. As far as the clicking I'm sure someone can say all of the things it could be, unfortunately I have no idea ATM.

Unrelated to the thread question, but thanks for posting that. I've been wondering what that box was on my '96 but keep forgetting to ask. :D

[93centsp]

Regarding DTC 26, below is a bit of information I grabbed from my '93 Century factory service manual:

(Page 1 of 3) QUAD-DRIVER (QDM) CIRCUIT 3300 (VIN N) “A” CARLINE (MFI)
Circuit Description:
Quad-Driver Modules (QDM) are used to control the components shown in the illustration above. When the ECM is commanding a component “ON,” the QDM closes the switch completing the circuit to ground.Each QDM output has a sense line. When a component is commanded “ON,” the voltage potential on the sense line is low, and when the component is commanded “OFF” the voltage potential on the sense line is high.
DTC 26 will set when the ECM is commanding a component “ON” and the voltage potential on a QDM A” sense line is high, or if the component is commanded “OFF” and the voltage potential on a QDM “A” sense line is low. Either of these conditions will cause the QDM “A” fault line to display “HIGH” and set DTC 26.
On all vehicles, the QDM “A” fault status on the Tech 1 will display “HIGH” with the brake applied or if the engine is not running. On vehicles with a 3T40 transmission, the QDM “A” fault status on the Tech 1 will read “HIGH” until the TCC inline switch is closed. These conditions will not cause DTC 26 to set even though the fault line displays “HIGH.” To simulate driving in second gear and change the QDM status to low, disconnect TCC connector and connect a test light between harness terminals “A” and “D”.
DTC 26 will set if: • The system is running in “Closed Loop.”
• Brake switch is closed (brake not applied).
• Transaxial in mid or high gear.
• The ECM detects an improper voltage level on a QDM “A” controlled circuit for 10 seconds.

[BxOutkast2009]

Ok folks...I know its been awhile since i posted on this, but with the weather in the northeast being crappy (REALLY FRICKIN COLD), which left me little time to really work on the car, so I haven't had a lot of information to post. But its warmed up and a nice tax refund helped on the repairs.

First: the Rad fan motor was definitely bad. I had it replaced along with the thermostat and now we have standard working cooling.

2nd: My fuel tank has in the tank or at the junction to the fuel line a hairline crack so i have to shop for a new tank. Ive driven the car and I've seen no noticeable loss of fuel when parked, but yeah its a problem that needs fixing soonest. Thats kinda out of my expertise so Its a garage on that one.

3rd: Cruise control is kaput. I will try to swap a sensor if possible, but i am checking for a yard donor.

4th: TRANSMISSION was leaking at the seal (the prior owner drove to and from the shore so salt air did nothing for the seals and parts of the undercarriage and lines) so i had a fun time driving 300 miles on a dwindling oil supply at 65-70mph until the car stalled out in my driveway. After trying leak seal ($10) I just knuckled up the time to change the tranny oil n seal myself. Brought the kit from Autozone for $13, put the car on ramps, and drained the pan. The gasket was a rigid plastic vs a flexable rubber. The tranny fliter? The car had a genuine GM part with MADE IN THE USA stamp...the replacement was a Made in China production...lol.

Sadly, all that work was for NADA...The hoses and clamps were so rotted they blew on start, so i lost $20 in oil and additives. New hoses and clamps $60 (garage and tow). :sad:

5th: A/C! I'm buying a Interdynamics R134a kit next week to changeover the R12 system in now (no a/c just hot air) It'll be about $45 and a few hours but doesn't seem that much a problem.

Just a note for those that may need them...I cannot CANNOT recommend MORE than to invest in a pair of portable garage ramps for doing repairs. It gets the right amount of height and way more sturdy than using jackstands. The best $40 Ive ever spent this week...lol