Yesterday I installed a Jet fan switch(Pt#60600). The Jet switch lowers the temp at which the fan comes on to work better with my 160* thermostat. The install was really easy. Just remove the factory switch from the drivers side head( its in between and just below #1 and #3 spark plugs) and put the Jet switch back in. Then you cut the factory connector off and crimp on the connector that came with the Jet switch. After that just hook up the wire, go for a test drive and your done, unless you have problems like me.

On the test drive(which was about 30-45min across town and back) the temp guage never got above 100*. About half way through the test drive I stopped to see if the fan was working and the temp guage wasn't or what. After checking, the fan was working and the car was hotter than 100*. When I started the car back up to leave the temp guage was pegged out over on the hot side, way past 280*. The guage stayed that way all the way home.

When I got home I got my laptop out and hooked it up to run WinALDL and see what I could find out. After hooking it up it showed the car to run from 194* to 213*. The guage was still pegged out though. When I tried unpluging the fan switch the temp guage fell to 100* and the fan quit working, but WinALDL still showed the temp. When I unpluged the temp sending unit(on the intake) the temp guage stayed the same and WinALDL quit showing the temp.

When I cut off the factory connector I noticed it had a lot of black tape and a crimp connector on it, I cut all this off. After this problem I took another look at the factory connector I cut off. It had two resistisor's(tan in color with two black stripes around them with a gold stripe on one side of the black stripes and a rust color line on the other side of the black stripes) hooked up inline.

Does anyone know whats wrong with the car(I feel that the previous owner had a problem and used the resistisor to band-aid fix the real problem)? Or what size the resisitors are(the ends broke off so I can't try putting them back, which I don'really want to do)? Someone PLEASE help me with this, I don't have any idea why the resisitor would be needed on the fan switch to make the guage work.

Thanks to any and all who help with this, Bobby

 

You replaced the wrong sensor.

The one you replaced is for the gauge.

The one you needed to replace is on the passenger's side, between #6 and #8.

 

No the guage or temputure sending unit is a two wire and its on the intake up front. There is nothing on the passanger side other than a plug. The problem has some thing to do with the resistisoirs.

 

If I recall correctly, the temp sensor on the intake manifold senses the temperature for the computer and has nothing to do with the temp gauge or fan switch.
Th fan switch is located on passenger side of cyl.head, between #6 and #8.
The sensor on the driver side of the head is for the temp gauge.
Jimjohn

 

On my '92 TBI LO3 there is a sensor or something on the passenger side down by the spark plugs on the block. It has a green wire. I am not sure what it is thought.

Bill

 

This is where the Jet fan switch should go. It is in the passenger head as shown.

 

I looked at the motor again today and I dont have anything on the pass side head. There is a plug between #6 and #8 spark plugs. All heads are like this though, being that a head can go on either side, thats why the plug is in the rear instead of being in the front, if that head was on the drivers the plug would be in the front.
I installed a Jet fan switch on my '97 Z28 and it went on the pass side. I had to remove the plug( it took a male 5/16 square socket to remove it) from the hole between #6 and #8 and put the Jet switch there, but its wire ran to a connector that went to the PCM.
As for as the sensor on the intake(its has two wires) I've unpluged it before and the temp guage would quit working.
JimJohn & AJ_92RS, have ya went and looked(today) and saw the sensor on your pass head? If not please do. AJ_92RS I would really like for you to look and be for sure, being your car is a '92 and the '91 & '92's had some things different from the older ones. I'm not saying that ya are wrong but this is problem really getting to me and I keep going to look for the sensor that ya say is there but its not there.
Also does anyone have a idea why the resisitsors were wired in to the factory plug. JimJohn, if you would unplug the sensor on your intake and be sure that it "has nothing to do with the temp guage", if you would please. Like I said I'm not saying that ya are wrong but everybody makes mistakes. And now I've got a problem and the people here on the TBI board are the only ones that I know that have the same motor as me and at least half-way know how the TBI motor's and wiring REALLY work.

PLEASE continue helping me with this and check your cars to be sure for me. All I'm asking is one to unplug an easy-to-get-at sensor and another to look real good and make sure of something, that depending on how much factory smog stuff you still have could or could'nt be easy to see. I know when I still had all the smog pump, air things going into the manifolds, the pipe coming from cat conv and EGR that the pass side was pretty full up with stuff.


Thanks and with a little more help maybe this thing gets figured out and fixed, Bobby

 

If thats true then something is seriously screwed up. That sensor is connected to the ECM only.

 

I've looked again after ShiftyCapone posted the picture(you can really tell whats there with headers). I have found a wire going to something on the rear of pass head, it's in the correct area but its dark so it'll have to wait till morning.

AZVolFan, as far as a green wire that is the color of the wire on my drivers side head. But you said yours was in the block? If so this is likely to be the Knock sensor. The sensor that I'm looking for is beyond doubt in one of the heads.

I looked in my '82-'92 Camaro{All Models} Haynes Repair Manual and it said the same thing as the Jet fan switch's instrutions, "the switch is normally located on the cylinder head between spark plugs #1 and #3 or #6 and #8".

I hope this wire that I found a few mins ago is the right one. I'll just have to put the factory drivers side sensor back in and reinstall the factory connector. But then there is still the question of: Why had the resistisors been wired in and what did they do? I still think they was somebodys band-aid fix for another problem. Oh well first things first, in the morining I'll look into the wire I found on the pass head. May be this is it, cause it did'nt seem like the fan came on much if any eariler.

Also I would still like to know what size the resistisors are? Like I said I broke the ends off of them removing them, maybe I won't need them after I get all this wired in right.

Thanks everyone so far, Bobby

 

Shifty,

So on a stock engine is that also the sensor for the fan switch?

 

Yup.

That is the fan temp switch. That is its location from the factory.

 

And if you ever put in headers thats the first thing you break.

 

Ha you can say that again. In that pic I posted the sensor os broken. I just recenty replaced it. It was kinda convienent having the fan on all the time.

 

I think mine is broken. Would this cause the fan to not come on if you are sitting in traffic while I watch my temp gauge rise???

I got the temp down by turning on the a/c.

 

I don't have to look today. I remember all to well when I changed mine to the Hypertech switch.

I had to get under the car to get to it. Antifreeze running down my arm, all over in my arm pit, burning like hell after it got there because I was working on the car on a 100* day and my arm pit was all sweaty.

Nope. I won't forget that.

 

No. If you break it your fan will come on all the time even when the car is not on. As soon as you turn that jey it will kick on and stay on until you shut the ignition off. It is sorta the default in case it goes bad so that you do not burn up. It is nice in the summer but not very good to promote fan life.

 

AJ_92RS, are you saying that you put a Hypertech Fan Switch in your car?

Iwent to the parts store a little earlier and got some heat shrink and a new end for the sensor I took out since the wire on the factory plug was to short to reuse.While I was there I saw new ends for a '86-'98 GM temp sending unit and it was a two wire connector just like the plug on my intake. I didn't question anyone about what specific modles it fit though. I'm using some alt wires to put the sensor back in though. The sensor uses a single flat blade connector and the alt wiring package has two of the single flat blade connectors in it.

Does anyone have any ideas why the resisitisors were wired inline on the temp guage's sensor(I decided if everone here says thats what it is that many can't be wrong)? I can't think of any reason anyone would put them there. I just hope it will work with out them.

Did anyone unplug the sensor on there intake to see if the temp guage works without it? I'm 95% sure that I unpluged it a while back and it killed my temp guage but will let ya know for sure what happens in the moring. Anyone else thats put in an aftermarket fan switch let me know how it worked for you. On my '97 Z28 I had the PCM reprogramed and it got it done in the programing but the Jet switch helped it even more.

Thanks alot guys without the help I've got here on the TBI board I probley wouldn't be running now. After letting the car set for 2 1/2 years it seems all the bugs it had before has doubled. I just hopeto get them worked out before my 388ci is ready. I'm going to get the rotating assembly and carry it to be balanced tomarrow then maybe the shop will get the short block togather in the next couple of weeks. I'm still wanting to use a 4bbl TBI unit on it and keep the factory ECM, but I'm going one step at a time. Howell keeps telling me my ECM will run it, but most here keep saying I'll need another injector driver board and I don't even know what that is or where to get one at?

Thanks, Bobby

 

Well I got the sensor back in and hooked up on the drivers side head. And I've now got the one on the pass head unhooked but the fan don't run with the switch on as someone said above & the oil dip stick is in the way. I'm going to refill it with water and see if the fan runs when the motor is running.

 

Passenger side between 6 and 8 = fan switch (what shiftey posted)
Intake next to the thermostat = what the computer uses
Driver head = Temp guage

Its that simple isn't it?

 

Alright I got everything hooked back up about dark. And all is back to working. Not perfect but at least its driveable again.

The temp on my laptop thats running WinALDL will show the car to be at 180* +2 or -2 and the guage in the car will show about 260* +10 or -10. I don't beleave its running this hot, I think WinALDL is showing the correct temp. It had never gotten this HOT before. Even before I started to install this Jet fan switch it only got up to around 220* or so and that was only in slow, heavy traffic.

I've sat outside and watched the coolent fan go on and off several times for about an hour. The motor seems to be running good. I can even tell that the Jet switch makes the coolent fan come on a good bit more often than before. On a test drive I took my laptop along to watch the temp and WinALDL showed the car to have never get above 208*, which I really like

But like it or not I think its back to WTF were those two GD'd resisitsors doing wired inline with the temp sending unit for in the first place. They had to correct it somehow or something, you think?

I just don't want to put more resisitsors back in and keep it band-aided up. I'd really like to fix it correct so that I don't have to worry about it all the time. This bugs the **** out of me! I've always liked looking and know temp the coolent was, thats kinda a good one to know. But now unless I care my laptop around everyhere I don't know if the heads are about to pop or not! But like I said the motor really seams to run quite a bit cooler. But like it is you'll never know for sure now. But even if I go buy two more resisitisors and put them in what ever is the REAL problem, is still there and waiting to bite me in the a$$ oneday if not fixed.

If anyone has any ideas on what the resisitors were put in for or what they fix or any insight on this at all, Please Help

Thanks, Bobby

 

If they were on the fan switch wire, and your fan switch is working fine now, you probably have nothing to worry about.

You said the car only used to get up to 220 in heavy traffic, doesn't the fan kick on at 230? Perhaps the resisters had somthing to do with getting the fan to turn on earlier.

 

The resistors are there becuase there is a problem with either the temp sender or the gauge which causes high temp readings.

 

PyRo9862,
They were own the temp guage's sending unit. The drivers side, betweew #1 & #3 pluges.

Brent,
Yea I talked to this other guy today and he said he had heard of people having the wrong temp sending unit and that it would be possiable to make them work like that. But he had never really seen it done before though.

Does anyone have the correct temp sending unit Pt# and is it on the sending unit itself?
Thanks,Bobby

 

Does anyone else have any ideas about why the resistisors were on the temp sending unit(sensor on drivers side head)? I've got to do something about this. I don't feel safe driving around with the temp guage showing 250*-275*.
Thanks, Bobby

 

Brent is right about using the resistors to calibrate a wrong part.
It's really simple how the system works if you just take a deep breath, forget everything you've done, and pretend that you just opened the hood for the first time.
Now for the explinations, some of which is rehashed from posts before this one.
The sensor in the intake manifold is for the ecm. It is a 2 wire thermoresistor just like the IAT sensor in the air cleaner. Winaldl reports the coolant temp using this sensor.
The sending unit for your temp gauge is a single wire in the drivers side head. This sending unit shouldn't be wrapped with teflon tape since it grounds through the engine.
The fan switch is in the passengers side head above the knock sensor which is in the block. Both of these sensors have a similar connector. The fan switch is a single wire that grounds out through the engine to turn the fan on (fan always gets +12 volts).
I think you've gotten this far already. Now you need to get the correct sending unit for the temp gauge and you can remove those inline resistors. Sorry I don't have the part number but go to any parts store and ask them to get you all of the sending units out for your car. The sending unit with a flat top like a thumb tack is the correct part.
Good luck and I hope you get it working.

 

Yea I was going to just go and get a new temp sending today but ending up sleeping all day(Yea I know, but it Sunday). Tomarrow I getting a new one and will post what happens then.. the one in the car now has no pt# on it that I could find.

Thanks everyone, I'll update lator, Bobby