OK, everything is wired up correctly... engine is cold, we start it... do all the first start up things... the engine tenp guage hits near 200... fans kick in....then off, then on, then off 74stingray4542007-03-25 16:19:41

Check the wiring for the relay(s), and verify it is as it should be. You may want to hook a voltmeter up to them to see if they are loosing power when the fans don't come on. If they are not loosing power, then the relay(s) may be defective. Even new stuff don't always work.
The "key on/key off/key on" scenario sounds like it may be a bad relay.

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Joel Adams
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"Money can't buy happiness -- but somehow it's more comforting to cry in a CORVETTE than in a Kia"

but one bad relay would not keep both from coming on or would it?

It shouldn't, but it would depend on how they were wired.
I'm assuming from your question that there is a separate relay for each fan. Depending on the schematics, or how the power feeds are wired, it is possible. Do both use the same temp sensor?

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"Money can't buy happiness -- but somehow it's more comforting to cry in a CORVETTE than in a Kia"

yes, both relays are fed from the same ign source, power source and temp sensor.

I have the fans hooked up to get power from a little two wire  ( one is red, the other is tanish colored with black stripe, its tapped to the red wire side)  relay thats on the firewall just to the left of the brake power booster, maybe thats not a good spot to tap into??? 74stingray4542007-03-25 18:05:29

That is the circuit breaker for the power windows on my car...does yours have P/W?
When I bought the '74, they had the 'lectric fuel pump hooked up there!
If yours is an early built '74, you may have the delay relay for the TCS(Trans. Controlled Spark) in that area.
You might try just connecting the power for the relays directly to the batt. for a test, to see if the problem goes away. If it does, then you'll need to find a new power source for the fans.

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Joel Adams
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haven't hooked mine up yet (will be shortly) but i believe schematics said to take power source from the positive off the starter.

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My schematics had me wire both leads directly to the battery.

yes, my car has power windows.... prob not a good spot to hook up to!

starting to install mine and called spal up. said there would be no problem with hooking the power line to the starter where the positive cable connects. also said main reason teflon tape can affect the sensor is that people use too much of it. one other tip the tech suggested was to run a groung line to the radiator as the supports usually have rubber inserts in them and may not be making a good ground connection. hope this helps out.

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thanks eddie, all good things to do, gonna run a ground wire to the sensor next time i feel like working on the car!

understand about working on it. i would run a good ground to the radiator not the sensor itself as doing that might keep the fans on all the time. when i get my radiator in i will hook a ground wire to one one the mounting screws for the fan unit as they are screwed into the frame of the radiator. just a quick question...did you have to unbolt the mounting frame of the radiator to remove it or can it be done with it in place?

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no, the rad support stayed in the car through it all, i just removed the fan shroud and the rad...

Well, i check the sensor and it has a perfect ground...

wonder if it has anything to do with the sensor being in the radiator. maybe better off putting the sensor in the intake manifold. hopefully will have mine in by this weekend. will let you know how it works. btw, i got the radiator with the connection for the sensor in it so i will check on how it works.

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[QUOTE=eddie20875]wonder if it has anything to do with the sensor being in the radiator. maybe better off putting the sensor in the intake manifold. hopefully will have mine in by this weekend. will let you know how it works. btw, i got the radiator with the connection for the sensor in it so i will check on how it works. [/QUOTE]

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Click on images for Before and After pics!

my temp sensor ofr the fans in on the drivers side tank, just below where the water comes into the rad, so the water is still gonna be plenty hot...

in post above, i called spal up to ask what should be used to seal the threads. they told me one reason they say not to use teflon tape is because people generally use too much. he said you could use it but at the least amount to seal it. i asked about rtv sealant and he said the basically the same thing, the least amount of anything to seal it. the connection on the radiator is under the return hose but with coolant circulating thru maybe it cools it too fast. just guessing on this. will let you know as i should be getting mine in hopefully this weekend.

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well, tonight it ran and it ran just fine... I THINK what was happening was the new rad and engine were still "burping" air pockets out as tonight when I check the water level it was low and took about 2 qts....

great to hear it.  you are so right, that something like that can really get to you and it winds up being a simple solution. 

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Way to go Dude. Makes a lot more sense than a little teflon tape on the sensor. Always remember to bleed out air when filling system.

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Click on images for Before and After pics!

What do you do to bleed it out? My uncle always said to run it a few mins with the rad cap off....

What I do is run the engine with the cap off until the stat opens. The level should drop down.  Then I throttle it a few times, hold the rpms up while I top it to the fill line and cap it. After I drive for a while and it cools down, I check the level. From there you should be good to go.

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Click on images for Before and After pics!

Hum, sounds just like what my unlce used to do.....

If you drill a small, 1/8" hole in the flat surface of the thermostat, it will allow you to fill the system with no problems, as this will create an "air bleed". You'll find that most thermostats you buy today have this hole, just for this reason.
The old method of running till the 'stat opens, then filling the radiator is a tried and true way to do it. It's also a good idea to have a recovery system, as this will let the engine take in what it needs as you drive.
Glad you got it fixed!!!

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Joel Adams
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Is there a down side to wiring these fans directly to the ignition,thereby the fans are running 24/7?

More wear & tear on them, as well as the alternator/charging system, for one. Plus, they don't really need to be running all the time.
At road speed, you can have enough air coming thru the rad. to actually fight against the fans, trying to spin them faster than they normally turn. This can create undue stress on the fan motor(s).
A better set-up, if you don't want to go with the temp. activated method is to just wire them thru an "On-Off" switch and relay, but you have to make sure the fans are on when they need to be on...

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Joel Adams
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I highly recommend using the temperature sending unit for the fan setup as the source of power for the fans.  I have dual spal fans in the 69 Corvette and the 69 Camaro.  The sending units for both cars are installed in the intake manifolds.  Some people wire them separately to come on and go off at diferent temps.  Both of my fans are run parallel.  They come on when they are needed (200) and shut off when the temp is below 190.