bud40oz

i keep trying to read all these different posts about cooling fans, from what i gather on older pre 90 models there is a relay on the firewall where on my 91 there is 2 relays down on the driver side radiator shroud, also the sensors are in different spots on my 91, from what i understand after reading all the different posts from over the years, a 91 model l98, should have the temp sending unit for the dash gauge on the drivers side between 6-8 plugs.. which i have but the wireconnector is broken and rigged .. easy fix for me.. the temp sending unit to control my fan on a 91 is supposed to be on the drivers side between 1-3. which it seems the original owner relocated to the aluminum intake when they put the carb/intake combo. but that is also an easy fix for me really, then. i have the ac compressorswitch which makes the second fan come on as soon as a/c is turned on. i am going to attempt to make the fans work properly using factory ecm and everything before i look for an after market fan control unit. if i have all new sensors and relays it should work properly. next thing i see is people saying that you must use the gm delco sensors or the system doesn't work correctly, so can anyone give me proper part numbers for each sensor i need and relays also? again this is for a 91 model.

after thinking on it for a while, i decided really i have to do is pull the wire from the temp sensor .. which in my case would be the one on my intake manifold as i described above? then ground that wire and my fan "should" come on with ignition on, correct? that should pretty much test the entire system and if it works tells me i need a new sensor, or am i thinking wrong here

Hot Rod Roy

My first observation: What is your problem? Or are you just trying to figure out how the system works? You apparently don't have a FSM ( Factory Service Manual ). Is that true? You NEED one!!!
Second is a question: If I ask you a question, will you answer it? If not, I'm out of here!
Third: How long ago were the mods done on your '91 to install that (horror!) carburetor? How long have you owned the car? Has the system ever worked right?



Probably a simple error, but plugs 6 & 8 are on the passenger (RH) side of the car, or is this a RH drive car ( in Jackson, MI )? I'm already confused. The temp gauge sensor is between plugs 6 & 8.



The primary radiator fan control in the '91 is by the ECU. The ECU uses info from the CTS (Coolant Temp Sensor) in the front of the engine, not between plugs 1 & 3. Do you still have this two wire sensor in the front of your engine? Is this "relocated" sensor one wire or two? Is there a sensor in your engine between plugs 1 & 3, or is there a pipe plug in this location? That sensor in your intake manifold may be for the secondary fan.

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I have the ac

Does the fan come on when you turn on the a/c?



So you want to get the fans working properly, then rip out all this wiring?

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If I have all new

Before you replace all of the sensors and relays, why not find out where your problem is? The ECU and all of the wiring also need to be correct.

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Next thing I see is people saying that you must use the

Easy answer: BS!

The CTS is a variable resistance device, and the signal from this device goes to the ECU, which establishes the actual engine temperature. Grounding this wire is wrong.

bud40oz

well. let me read through all of this and answer each question in order for you but first let me run you down on how i even have the car.
i was at work one morning and a buddy of mine called me and says hey. i know a guy who has a 91 corvette he is trying to sell me for 500 bucks, i said ya right. you mean 5000.. nope i mean 500. so i finally got to meet up with the guy and sure enough he meant 500 bucks. this was last november 19'th, my birthday. i peeled the 500 bucks called a flat bed truck and had it towed home as is. never knew or seen the guy i bought it from before. all i know is he told me it had a fuel leak and caught on fire under the hood and luckily someone ran out with a fire extinguisher and put it out or the whole car would of gone up in smoke. and really the fire damage appears to me to be minimal, however. the owner had his buddy "fix" the car by taking all the tuned port stuff off and installing a torker 2 intake and edelbrock 4 barrel. which after reading i see why they chose that set up. there is a torker 2 intake i have seen that says fits under stock hood of corvette.. so that's the route they went, obviously. even though the boneheads used a 1 inch spacer/adapter plate on the carb and ended up cutting a nasty hole in the hood anyway.. the guy said he drove it to a car show with his wife in grand rapids mich or some place out of town a way and it over heated.. well.. they have a thermostat housing that points straight in the air instead of forward, i am thinking that is part of the over heat problem.. they also had the fans coming on as soon as you hit the key.. also he said the engine had run on.. well we all know a fan hooked to ignition runs until the fan stops. so i figured that was the problem there. now.. the fans do not come on at all and my temp gauge has stopped working also but i found the wire for that laying off to the side. it was working i saw it.. i tried to wrap the broken wire around the sending unit stud there on the pass side but i don't think it is making a good connection. i am going to solder a wire on it, use a single terminal weather pack connector for male/female and connect it back up this weekend. hope it works

i know very little of the cars history or what has been done or how well any of it was done, i have absolutely nothing as far as original tuned port injection goes. and i do not even see any of the wire harness under the hood for it. i am fine with that.. i guess it is what it is. a 500 dollar hot rod toy for me, which i have wanted for a long time now. never thought it would be a corvette but hey.. it could be much worse right? the car really is not all that bad, first thoughts of a 500 dollar vette is wow PILE OF JUNK. but the car is a triple black convertible zf 6 speed with leather interior the dash and everything is in quite good shape also. a couple minor flaws in the seats and carpet is worn some.. but it has a brand new top the guy said he paid almost 2 grand for that alone it is pretty nice really. engine compartment is currently ugly as ugly can be though but i can fix that.

first to answer is no, i do not have a fsm i would love to have one as i am quite capable of doing repairs myself i have been wrenching for 30 years rebuilt many engine and entire vehicles on a backyard and professional base and i know a factory service manual tells you about anything you could ever want to know.

second is, i pretty much understand how the fan system works. i didn't really know a second fan came on with a/c but i do now thanks to corvette forum though, actually i think it was you... in another post.. lol. i am on the fence between trying to make the whole system work as factory normally, i do not like the temps it is set up to run at though. but i have been looking around for a tuned port injection system to put back on the car because i know as is with carb the value is gone down the drain but deep down i am a hot rod type of guy and i love a carb to be honest, that is another post though really.. some of these new carbs are really nice btw. i have also been looking at a flex lite fan control that looks like it would fit my situation also. but that would be better situation of me staying with the carb set up and going with the brodix head and building the **** out of the engine.. which deep down again.. that's more my style.. i do not really plan on driving the car hundreds of miles out of town.. i plan on driving to state parks and picking up women and having a good old time and burning off tires and you know...
ok third, yes, you are correct i put driver side 6-8 wrong. it is pass side of course.. and yes there is a plug between 1 and 3 which made me think they did that when they changed the intake and relocated the sensor to the intake since there is a single wire sensor on it, i could take a pic if you like. i assumed it is the fan switch sensor.

lets see this is turning into a book, fourth question, no.. if i get the system working properly using the factory stuff or even replacing sensors/relays i am good with that really. i will not rip anything out.. i am a firm believer in, if it aint broke, don't fix it plus i can use my budget on better things like a new tires and rims.. or a deck for my house i have been wanting for 5 years.

i think i answered everything. i got lost in it but mainly i want to say thank for for even taking the time to try to help me.. i didn't want to jack that other post there.. i just wanted your attention on this . i will admit right now.. i do not know a damn thing about a corvette, never owned one never thought i would have one. i am quite capable of fixing stuff though with the proper instructions

bud40oz

this is some pics of the car..

this one is the first time i saw the car the day i bought it. 11-19-18
guys wife told him to get that pos out of the garage so she could park her new jeep in it... it was always garage kept before this and has been in my garage all winter..

bud40oz

it took me about 5 hours to figure out how to open the roof up, turns out it was just stuck a little and had to use some force to pop the pass side loose, it works perfectly now, called the guy i bought it from and he said. i do not know how to open it. i had it installed brand new and new took the top down once.. i figured it out after about 12 beers.

bud40oz

here is where it starts getting ugly, you can see the sensor there on the front of the intake, that's what i am guessing is the fan switch and a good chance part of my problem. especially if that radiator hose i explained is not flowing water properly and has air trapped in the system, you should also be able to see the said upper radiator hose in question going straight up in the air. i plan on finding a new thermostat housing which point forward instead of up to the moon this weekend.

bud40oz

the car has probably never ran "right" in my opinion it does start and it will hold an idle.. but withing the few short hours i have been able to look?work on it over the winter months i have noticed several things that has made my head shake and think damn. them guys didn't know ****. for one i can tell by looking at the distributor cap that the distributor is not installed properly. again. easy fix and i have a very nice digital snap on timing light that says i can make that problem go away in about n hour.. carb is junk edelbrock and not tuned properly... plugs are fouled i am sure..all simple fixes but still...i have owned this car for what 6 months or less and have only had maybe 5 hours of looking time at it so far and done pretty much nothing to it at all so far but half *** diagnose a couple problems. it is about to get warm soon here and i will be working on it every night soon, starting this weekend so. things will be turning around for the car...now that it has a owner who can work on it himself... other owner was a check writer not a wrench

bud40oz

okay new question for anyone who can answer. if i remove the ecm completely and make the car brain dead basically. will the factory dash gauges all still work? or will i have to go in and re-wire it all?

bud40oz

ideally i would make this car an ls swap.... but i am not really that rich. surei can throw a few hundred dollar bills at the car hear n there ya know and some day i might come across a totaled out older LS based truck with all the wire harness n everything i would need but for now. i am trying to make the most of what i have with this old vette i bought for 500 bucks as is.. with no fsm or even an owners manual, it should make a fun little hot rod for the summer months.. i know 99% of you guys look at that engine compartnent there n think wow. car is ruined...but me. i vision a nice set of ceramic coated hooker super comp headers.. a shiny new demon carb,.. msd ignition.. can't help it.. i am a 50 year old hippy guy who likes it old school simple

bud40oz

Before you replace all of the sensors and relays, why not find out where your problem is? The ECU and all of the wiring also need to be correct....
thats why i am trying to talk to you hot rod roy..... i am asking for your help. but i will probably figure it out on my own i suppose regardless, or just get fed up and buy the flex lit fan control kit.. the ecm may be smoked for all i know. as i said the car was in an as is condition when i purchased it..i can take that ecm out n smash it in the drive way also.. i have done it before with gen 3 camaro's

yd328

For 500 bucks w/ a zf6, hell yah. Not bad, get the front wheels switched around, cleaned up and running good. It would be nice to see the original induction system back on it but thats just my opinion.

Gary

Kmcoldcars

The front wheels are on correctly. The rear wheels are the ones that are wrong and need to be switched from side to side. Unfortunately that means the rear tires have to be taken off and switched too as the tires on a C4 are generally directional.
That looks like a GREAT car for $ 500.

bud40oz

yes, you are correct the tires are actually mounted on the rims wrong. i thought i could just change the rims to be right but the tires are all going the right direction i do not know who mounted the tires but damn the original owner should of made them fix it when he noticed, the tires are not even the proper sizes so when i get all the bugs worked out i will buy the proper goodyear tires, they are only about $650 or so i think. cheap, i paid a whole lot more than that for my truck tires

65Z01

On my '89 the rear relay on the fender under the MC is the CAGS relay; the front one controls the booster fan.