Electric coolant fan wiring relay

[Highsteel]

I got my fan installed and wired up according to the kit manufacturer specs I got from the parts store. All went well, temp stayed normal, until I went to turn the truck off. Now there is like a 2 second delay from the time I turn the key off til the engine turns off. Its not dieseling, it just stays running for a bit, then shuts down.
Is this because there is no relay? I have a relay that came with the (used) fan but I wasn't sure where in the circuit to put it.

Jerry

[jhow66]

Your fan is acting as a generator while it is turning after you turn the switch off thereby adding a small amount of current to the system. When it stops turning, engine dies. Add a one way diode in the power wire to fan or add the relay.(between switch and fan)

[Longhorn Man]

I would never even consider running a fan like that with no relay.
Jhow is 100% right though, the fan is acting as a generator and making enough power that it back feeds through the system and triggers spark to keep the engine running.

[Highsteel]

Originally Posted by Longhorn Man

I would never even consider running a fan like that with no relay.

I guess if I possessed your unlimited and infinite wisdom I wouldn't have needed to make such a clearly ignorant post and you would not have had to make such a pompous and condescending reply. If I really wanted belittled like that I'm sure I could find a forum that catered to just that sort of treatment.

Thank you, jhow, for confirming my suspicions. I was pretty sure that a relay was needed, I just wasn't sure where in the circuit to put it.

[pcmcobra]

Originally Posted by Highsteel

I guess if I possessed your unlimited and infinite wisdom I wouldn't have needed to make such a clearly ignorant post and you would not have had to make such a pompous and condescending reply. If I really wanted belittled like that I'm sure I could find a forum that catered to just that sort of treatment.

I don't think he meant that in a "belittling" way, he was just making a statement, that he would not do it that way.
Anyway, ya a relay would help.

[67shortie]

[Highsteel]

True pcmcobra, I was not 'belittled' as nothing was said against me.

I apologize to you, Longhorn Man, for insinuating that you belittled me, as you most obviously did not say anything derogatory against me.

Jerry