Help! cooling fan, src

[italian job]

hi all I registered here just today and bought my zr1 less than a week ago. I'm Italian, so please excuse me for my poor english language

My 90 zr1 has 35.000 miles and today look very very well, but has many problems...

First: temperature raise near to 260F if I go at low speed or during stop and go or climbing a little hill at low speed and also in the traffic. I already know: I must clean radiator and ac condeser as soon. But I think one fan is not operative. I see car has 2 fans, so I make this try: I run engine and wait for temperature raise. looking at the fans I found the left side fan (the one placed on top and easy visible) don't start. While the right side fan (the one placed at bottom) start only when temperature needle is near 260F.
The fan itself is not burn or damaged and is working, also all cables are ok, and also the two fan relais are ok (I'm not sure "relais" is right english word: I mean that two little black boxes, with rounded edges, placed on front left side, near radiator box. These two little boxes are wire connected to the fans)
So, anyone know what can be the source of this problem?

Second: SRC service light; when I purchased the car the service light was already on. The SRC is actually not operative, so I first check for bad or damged wires, but all visible wires and connectors seem ok. Then I search for a damaged actuator, I pull out one actuator at once, disconnect the car's cable and test the actuator alone, at end all four are working. Then I pull out all four actuators but still connected to their cables on the car; every time I turn the ignition key all four actuators run for about 1/2 turn then stop.
Control box cables and connector are also ok.
Any suggestion?

Thanks

 

[gbrtng]

Both fans should run when the AC is turned on regardless of engine temperature. If the inoperative fan spins freely, check the terminal block behind the battery for a blown fusible link - there are about 6 of them and there is one link for each fan. Occasionally a fan will pick up a rock and then the fusible link opens up. If that's what you find, send me an e-mail and I'll help you further.

Check to see if each shock's shaft turns easily - you may need a pliers, but they should turn the full half turn. If they do, you should be OK after you clear the stored codes.

 

[Hib Halverson]

I know some will perceive this as flippant but, considering the car you bought is complicated electronically and it clearly has a lot of issues, if you are going to try and make repairs yourself, I think you 1) need to be able to read English well and 2) purchase the Factory Service Manual. There are a number of sources for these in the United States, but, unfortunately, the "FSM" is not available in an Italian translation.

As for the Selective Ride, besides the service manual you can read an article here on the CAC at: Corvette Action Center | Tech | C4 Corvette's Selective Ride Control - Six Steps for a King's Ride

Also, do not use pliers to turn the shock valves. If you need pliers to turn the valve, the shock absorber is defective. SRC shocks can be rebuild by Bilstein in the U.S.

As for the ECT, first know that the gauges on the instrument panel are highly inaccurate. Unfortunately, the 90s do not have the digital display function that the 91 and up cars had, however, there is a way to put the ECT on the hvac display and it reads in celsius. Problem is I can't remember how to do that and my 90 FSM is not available right now.

In the FSM are instructions on how to troubleshoot and service the cooling fans.

The small black boxes are called "relays" in English.

Lastly, what part of Italy are you in? I have acquaintances in Florence and Milan. Both are Corvette owners and are in the Corvette Club of Italy.

 

[italian job]

thanks for answer qbrtnq
in my car only the right side fan run, and only when needle is almost at 260F. the left side fan not only spin freely but also run perfect if I connect it to a 12V source. Will check soon the fusibles.

all four shock' shafts turn easily and all shock's parts are not damaged. I don't know how clear the stored codes, please can you tell me how to?

 

[italian job]

Yes Hib, I know well this car is complicated electronically, and also know it has a lot of issues.
yes I'm able to read english...not too good, but enough to understand.

At this time I don't have the factory service manual because I bought the car only last week, but soon I will have. Also I already bought the original owner manual and will have soon too. I own other 6 cars, so I know how much is important to have a service manual...

Will read that article reagarding SRC, surely will be very useful!

Sure I tried to turn the shock valve only with my fingers, and all valves are free and still do their job (soften or stiffen car's suspensions) so I think source of problem are not the shocks.

Yes relays! now I remeber: I know but forgive the right word!

I live in Sicily, city of Palermo.

 

[Hib Halverson]

Sicily, eh. Not many roads there. You'll get bored quick.


Once you get your service manual, I'd use it's instructions to diagnose the cooling fans. Also, in the section of the book on HVAC, you'll find instructions on how to get the A/C display to show engine coolant temperature in degrees C. That will allow you to see what the actual coolant temp is rather than just guessing at it based on the inaccurate gauges.

Good luck "italian job"

 

[italian job]

hmmm not too bored....don't forgive Hib, Siciliy is the land of world famous Targa Florio race Here we have so many curves that every road become a racetrack!:L

Regarding FSM I still searching for... Ebay have FSM but not for 1990, (there are manuals for 1991, 93, 95 ,but think is not same thing)

Also I see there are at least 3 manuals: a manual for c4 corvette; a manual for LT5 engine, and a manual for elecrtical system. I must purchase all manuals, or there is a single big manual including all of all?
You know a source selling FSM online?

And a source selling new PROM? I think my prom is bad because the car stalls, suffer of rough running and has high idles.

Thanks

 

[rebelZ]

hmmm not too bored....don't forgive Hib, Siciliy is the land of world famous Targa Florio race Here we have so many curves that every road become a racetrack!:L

Regarding FSM I still searching for... Ebay have FSM but not for 1990, (there are manuals for 1991, 93, 95 ,but think is not same thing)

Also I see there are at least 3 manuals: a manual for c4 corvette; a manual for LT5 engine, and a manual for elecrtical system. I must purchase all manuals, or there is a single big manual including all of all?
You know a source selling FSM online?

And a source selling new PROM? I think my prom is bad because the car stalls, suffer of rough running and has high idles.

Thanks

You need all three books. You are correct they are year specific.

Most likely not the Prom. I'd check the Map Sensor hose at the back of the engine. Search the forum for information on what to look for.

Rich

 

[italian job]

Many thanks Rich, wil search for all 3 books.

Will check the map sensor hose.
But I know there is a better replacement for early type prom. So I want replace the prom also if maybe it working at his best.

 

[Hib Halverson]

If you look for these books on eBay be certain you're getting the correct books before you bid. Do not bid on any FSM with a white cover. Those are preliminary 90 manuals.

You're better off buying the books new from either Helm, Inc. the publisher or one of the Corvette parts vendors in the U.S. such as Zip Products.

Also, if you have been there yet, check out the ZR1 Net Registry web site at ZR-1 Net Registry Home Page

From that site you should also be able to subscribe to the ZR1 net email list.

 

[italian job]

Thanks fo these tips! I just asking to me why a white cover manual listed on ebay was so cheap. I bough LT5 supplement and now there is a guy want give to the other 2 manuals for $70.00, think is good....
Zr1 net registry is very good!
Thanks Hib

 

[italian job]

Your suggestion about cooling fans was very useful!
Behind the battery I found 10 fusible links, all connected to a single bolt, all fuses look well (I tried to gently pull out and push is) so I clean all wire terminals, and all two fans now running ok when I turn on the AC! Now I must try if cooling fans run right also when I drive the car.
After cleaned wires terminals, also the windishield wash motor reborn!
Many thank