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I have a Champion radiator with twin electric fans. I am running one relay and I just ordered a second relay to split the fans.
but now Im stuck on the side of the road without fans and the car got too hot to drive. I swapped my fuse at the fuse box but they still did not come on. I grounded the temp switch and I can hear the relay kicking on but the fans dont move. Im stumped.
Just sayin- might not be the fans-
Sounds like you have torched the relay(s)- I recommend real Bosch relays ( few bucks more) not the China stuff.
Dewitt's radiator might solve the problem.
Also don't know how the fans are wired- or if you've upgraded the electrical to handle the extra draw from the fans.
IIRC you were messing with a one wire alternator - which I don't recommend.
Done correctly with quality stuff- you'll never have an issue.
My fans don't even run if the car is moving. They will only come on if I am stopped at a light. I have a real-time calibrated digital gauge that shows the accurate temperature, and shows exactly when my 195 degree temp switch turns the fans on, and then turns them off again at 185. Two fans, two Bosch relays, two fuses, two circuits, but a single temp switch in the intake manifold for grounding the two relay coils.
I only mention this because you didn't say how you are stopped at the side of the road. Do you need your fans when you are driving normally? Were you stuck in traffic at the time? Is there some other problem with your cooling system (or timing) that makes you need the fans?
I agree that the relay is a likely culprit. The standard Bosch-style relays are available at any Autozone, but do check with a multimeter throughout the circuit, before and after the relay, to see where the power stops flowing.
It fits in the storage compartment and is soft sided - it has a little bit of everything in it, and I also have about 4ft of 10 AWG wire in it too for just such an issue.
With just the little test light, you can test where you don't have power and where you do. If you determined your relay is bad, you could jumper it with a little piece of wire or worst case connect your fan right up to the pos lug on your alternator and get you home.
You have to have the ability to do a little on-the-spot troubleshooting and maintenance with cars this old, things will come up. A bolt will come loose, a wire will break, a hose will split, and you should at least have a handful of tools available with your car so you can make it home when it happens.
So I made it home. I had a spare relay (not sure why) but when I plugged it in the fans came on and I limped it home.
I certainly know what my issue is and I wont drive it again until I add a second relay which I already ordered. Its just the single relay seemed to work fine for such a long time…until it didnt.
I also cant hear the fans come on because my car is so loud with the side pipes so my only clue that they are not running is if the temp starts to climb. It has gotten e paranoid where I drive with one eye on the road and one eye on my temp gauge.
So I made it home. I had a spare relay (not sure why) but when I plugged it in the fans came on and I limped it home.
I certainly know what my issue is and I wont drive it again until I add a second relay which I already ordered. Its just the single relay seemed to work fine for such a long time…until it didnt.
I also cant hear the fans come on because my car is so loud with the side pipes so my only clue that they are not running is if the temp starts to climb. It has gotten e paranoid where I drive with one eye on the road and one eye on my temp gauge.
I'm glad it worked out!
Are you crawling along in traffic? My sidepiped car runs at 160 or so at highway speeds. 170 on Virginia roads, and as low as 150 coasting down a mountain. This is with a 180 degree thermostat, with a small bypass hole. If you need the fans to come on while you are driving, perhaps a second relay is not your only problem.
When you add the second relay, consider an indicator LED or two to let you know when the fans are on (energized by the load side of the relay). I can hear my fans over my sidepipes, no problem.
I have a Champion radiator with twin electric fans. I am running one relay and I just ordered a second relay to split the fans.
but now Im stuck on the side of the road without fans and the car got too hot to drive. I swapped my fuse at the fuse box but they still did not come on. I grounded the temp switch and I can hear the relay kicking on but the fans dont move. Im stumped.
Sure sounds like a relay problem. I assume you're running power right off the alternator so the whole circuit should be pretty easy to check. Did the relay come with the fans? Make sure the relay has the appropriate amperage rating for the fans. Doubling up on the relays could help, as long as the relays are good as I'd think just one fan running should keep operating temps in line.
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Sounds like to many amps going through a single relay. Did you upgrade the wiring to the relay and after it? where are you getting your power an how are you dividing it between the fans?
If you have your radiator seals installed in front of the radiator in the air box then you wont need the fans once you get above 40 as long as you have a good air dam to force air up into the air box. WWhat year is your vette?
The cube relays (Bosch) , which I assume you are using, are good for about 20Amps Max. each. What's the amp draw for each fan? You may have exceeded the rating of the relay. Chevy used a cool setup using three relays and two fans, I noticed it on my Dad's 2000 Monte Carlo. Not sure about this, but I think it is a parallel/ series arrangement of the fans. But it's the three relays that caught my attention. Maybe this is the way to go. I wish I had more info for you, but Google is your friend!
Two radiator fans will not reliable run on a single Bosch style relay, period.
You need a relay per fan, and you need good wiring and terminals in the relay and fuse sockets. Lots of junk being sold these days called 30A or 40A but not capable of actually supporting much more than about 10A reliably.
Vehicles with stock electric fans can easily go 100-150k miles without any issues, so arguments about why electric fans can't reliably work are just noise.
From: Who says "Nothing is impossible" ? I've been doing nothing for years.
I have a failsafe wire to my fans. It is a thick wire that connects the battery through a heavy duty switch the directly to my fans if my fan controller, fuses, relays or anything else fails.
From: Who says "Nothing is impossible" ? I've been doing nothing for years.
Originally Posted by 1Hotrodz
The cube relays (Bosch) , which I assume you are using, are good for about 20Amps Max. each. What's the amp draw for each fan? You may have exceeded the rating of the relay. Chevy used a cool setup using three relays and two fans, I noticed it on my Dad's 2000 Monte Carlo. Not sure about this, but I think it is a parallel/ series arrangement of the fans. But it's the three relays that caught my attention. Maybe this is the way to go. I wish I had more info for you, but Google is your friend!
This third relay is probably designed to take the startup current surge which is usually much more than the rated or nominal current the fans draw while running. There are electronic devices to ramp up or slightly delay the current on startup instead of hitting the relay instantaneously with a higher current than the relay is designed for.
as I said before- a real Bosch relay not just a Bosch "style" Chinese knock off.
They are not created equal- left junk- right real Bosch- the only one I use. Easily have used them in the thousands of products/applications-have never had one fail-
I have written before many times electric fans are the MOST POORLY ENGINEERED aftermarket part you can buy.
They never take into account PLENUM SPACE, blocking the cooling fins, poor thermostats and nothing is for free...AMP and WATT draw.
I know a guy who killed his alternator (working its guts out) and battery as well as the main cables sheaths melting. FOR WHAT?
You are far far better off going back to the Chevy fan and shroud. 1,000 Chevy Corvette engineers can't be wrong.
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I hate my electric fans
