I am new to this forum thing and new to owning a diesel and need some assistance. I have a '04 F350. 6.0 L when I bought it, there is a switch on the left of the steering wheel that I have no clue what it's for and the used dealership couldn't help me.I think it may be a high idle switch bc when I flip it up it idle slightly higher but not by much however I think it performs better with it on (faster response time etc). Secondly, when I go to start it , it takes a couple cranks before finally starting. Why can I do to have an easier start? Third, when I let it run to warm up before I go out the drive, it randomly idles higher (from 500 to 1k RPM) then when I hit the brake it goes back down. Is this normal or something I should have checked out? Thanks for the input.

 

When cold the idle raises a little to warm up quicker but drops to allow you to change into gear. Factory setting . . Post pic of switch if u can . .

 

Can't get a picture to upload via phone but it looks like an aftermarket blue flip switch. Up and down. It doesn't indicate on off or anything. When flipped up I notice it sound like it idles higher, it isn't noticeable by the RPM meter however.

 

It is possible it is just what you think. There is a thread on here on how to wire a switch like that in.

The truck is prewired from the factory for the high idle and used if the truck came with a PTO device. Off the top of my head I can't remember the color code (green & purple maybe) for the wire.

When I did mine I took power from the feed for an uplift switch. If the switch is on and the parking brake is set the truck will "high idle". Step on the brake or release the parking brake and it will kick back down. So if you have the switch in the "on" position and start the truck it will start and idle at the "normal rpms" for a few seconds then kick up to the higher idle. Step on the brake to put the truck in gear and the idle will kick back down.

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here is the link to that thread - hope it helps


https://www.dieselbombers.com/ford-p...-you-guys.html

 

This is great guys thanks for the info. How about the hard start? I know to turn the key forward until it primes then try to start, but sometimes it still takes a few seconds before it finally turns over. And is there any other tips, pointers, and upkeep directions you can give to a first timer like me? It's an '04 with 90k miles and lots more to go and I want to do what I can to keep it running in purrrfect condition.

 

Test the FICM - easy test also described in a thread on here.

Does your glow plug light come on when you turn the key? - Do you wait for it to go off?

 

Like I said before new to this sort of thing so I will check up on the diesel lingo and see what test you are talking about thanks. And if by glow plug you mean the coil looking light yes it does come on and I have always waited for it to go off before trying to start it. But to no avail it sometimes takes a little bit to start.