High Idle Engine Mod - Upfitter #4

[Rattler-FX4]

I've had this hooked up to the #4 upfitter switch for well over a year with no issues. Now it doesn't activate for some reason. The light on the switch lights up when flipped, but nothing. The only thing I've had done to the truck was to have the EGR blocked, new oil cooler and new HPOP about 2 weeks back. Any ideas as to what I should be looking for? Re-did everything and it simply won't activate. On the #4 nor the #3 switch.

[F250SixOH]

Have you checked the voltage?

[ve7fet]

You checked the associated fuse for that upfitter switch?

Probably want to probe the aux 4 upfitter wire with a test light or a volt meter and see that when you turn the switch on, you're getting 12V.

Other than that, you need to verify all the conditions to enter high idle are being met... things like being in park with the emergency brake set. So, you may need to check those switches too and see if they are working correctly.


Lee

[Rattler-FX4]

Sorry - been super busy.

Have not checked the voltage but will tomorrow. All conditions are in place to work as the factory bump in rpm kicks in after it's idled a few minutes but not like the high-engine idle. I've used this for well over a year.

[Rattler-FX4]

OK, voltage when switch thrown on. Switch led lights up. Nothing else. Have noticed my gauge panel parking brake light isn't on as well. But this morning, for whatever reason it was when I started her up. Hit the #4 switch more out of habit than anything else and the high idle kicked right in as it should. Foot on brake pedal, high idle drops out. Foot off, back on. Drove a bit today and noticed emergency brake dash light wasn't on anymore when I parked at Lowes. Nor did the high idle work. So, I thought maybe the bulb was burnt out but thinking it's possibly the switch now to all of a sudden come back on today. Will check/replace that sometime over the holiday and update hopefully the last time on this one....

Merry Christmas!!

[ve7fet]

Sounds like you have a bad emergency brake switch.

It is one of the conditions required for high idle (emergency brake set). It is NOT required for the standard "idle-up" that the truck will do on its own after starting (parking brake does not need to be set for that to work).

Check, adjust, repair, or change the emergency brake switch, and you'll probably make it all happy again.


Lee

[Rattler-FX4]

Thanks. Took it off and re-hooked it and it worked. Seems to have simply just come loose a little. Not sure how seeing where it's located, but thanks again!!

HAPPY NEW YEAR TO ALL!