cooling fans stay on key off,
Installed a 1200hp kit on 540BBC, Used fan1 and fan2 wires to 2 relays for cooling, fans work fine, went on drive, shut car off, nothing running, came back to car, one fan running, relay is good, anybody have this issue or do i need to wait on fone 3 days getting in touch with fitech tech support? It's Still under warranty.
I had the same issue. I added two diodes between the key on line and each relay. I sent a .bmp of the schematic.
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i kept mine simple i just used a aftermarket adjustable fan controler and did not use the fan 1 or fan 2 wires
I don't know for sure, but it is probably intended for the fans to stay on until the temperature goes under the threshold. Temperature typically increases when the key is turned off so they may be on for a while. I remember having a stock Fiat back in the 80s that had an electric fan and the fan will stay on couple minutes after the engine was shut off.
I don't even give power to the fan relay with the key off, solves that problem.
what most people miss is if the fans are running with the key off unless you are running a electric water pump on a relay with the fan control you are only cooling down the radiator the motor is still hot i run the autometer cooling relay kit a electric pump and the electric taurus fan when my power switch is off everything is off but if i leave it on i can cool from 200 to 100 in about 3 or 4 minutes if i need to but i also have two 1000 amp batteries so i can be reassured of a restart
I agree to this logic up to a point, but what about the principle of hot water rising and creating circulation (albeit poor) that was the only form of cooling before water pumps were developed and also the cooling effect of air passing over the engine, this is a normal part of heat transfer along with the radiator.
Regardless of the science behind it I believe that if you don't have a timer they could stay on for a long time relying solely in convective circulation. I assume that in those OEM application where the fan stays on they likely use some sort of timer, unless FiTech has a built in timer. To be sure, I will do as Bdhulderman suggest and supply only key on power to the relay that will activate the fan.