I went to put the truck in 4hi and it wouldn't go in 4x4. I have the shift on the fly and I know it didn't go into 4x4 cause the light didn't show up. I tried again a few minutes later and it went into 4x4 fine.
Was the transfer case too cold or is something messed up on the truck?

 

When you engaged the 4x4, did you notice your heater blower revving up a bit?

When I turned up my blower a bit, I noticed the 4x4 light going on (and the blower didn't change a bit).

 

I now figured out that the problem is only when the truck is moving. If I'm at a stop it will engage fine but when driving it won't work.
Is the shift on the fly feature broken?

 

You can't do it if you are going more than 20 mph or so. 4 Low requires you be in neutral.

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97 F-150 XLT 4x4 ORP SuperCab

 

Something is wrong I have engaged my 4 wheel drive at 45 mph before. I think you can do up to about 50-55mph , but never tried it over 45.
conway is right about 4Low you must be stopped and in Neutral.
Try engaging and dissagaging it a few times and see if it gets better. The shift on the fly uses a vacuum swith to engage the 4wd so maybee it was just stuck. It may work ok after a while.If not bring it to the dealer.



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1999 F150 4x4 4.6V8 regcab/shortbed
Oxford White with Wedgewood Blue two tone, with Blue Captains chairs
Bullet Cat Back, Superchip, K&N FIPK Intake.
Centerline Saber rims 17x8" with Firestone GTA 275/60hr-17 tires.
Alpine CDA-7845, ADS P640 Amp, Focal Poly Kevlar seperates.
SILVER 2001 LIGHTNING on order
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