Hey guys. I need some help understanding and using what's called a delay relay. I know what they do, but when I go on eBay or one of the electrical sites I get overwhelmed with all the information about amps and numbers and so forth and end up not getting one.

Maybe if I tell you what I'm doing, you'll have a better idea of what I need and will be able to guide me through the purchase and installation. I have been running a dual fan on my radiator for several years. However, when the fans turn on there is a huge spike for a millisecond that causes the engine/ignition to stumble. I would like to eliminate that stumble. I know there are soft start PWM controllers out there that would solve this problem, but what I enjoy about the system the way that I now have it wired, is that if one of the relays goes out, I just pop a new one in and I'm on my way again. With one of the controllers, if two years down the line it dies, I'm stuck wondering how to replace it. Anyway, I run a Ford contour/mystique dual fan. Each fan draws 20 A running. I have a good strong relay triggering each fan. Each relay is ground activated through a thermal switch on my top radiator hose. I want to install a delay relay to inhibit the activation of one of the fans. That would mean that when the thermal switch trips the relays, only one of the fans would initially activate. And then the other fan, that I would wire with the delay relay, would activate 10 or 15 seconds later. It is my hope that by installing the delay relay I will be eliminating the ignition stumble.

I thank you in advance for any help offered. Maybe I should also say that I've been running the system from several years, and that it has a good 130 amp alternator supplying power, that the relays are beefy enough to handle the current amperage, and that the whole thing is wired with the good quality 10gauge wire.