foolwitools

Hi Guys,

I tried to do a search but it's like looking for that tiny part you dropped in the grass............

06 xlt 5.4 auto 4wd

My 4wd is intermittent. sometimes fine, other times nothing. no light, no clicking sound, nothing. Sometimes if I shut the ignition off and start it again it works. this has been going on for 2 months or so.

It was snowy this morning and of coures it wouldn't work..... so i thought I'd throw some parts at it. I got a new solinoid ( the one behind the battery.,. $45 from ford) and changed it. nothing. no light, nothing.

So I put the old one back and... nothing.

I had to go to the store a while later and tried it again.... and it worked! I cycled the switch several times on the way to the store and it worked every time. It worked on the way back too.........

but I expect that tomorrow morning it won't work........ who knows.

What do I change next?

Bob the Fool

jhelrey

I would unplug and clean all of the connections regarding the 4x4...

foolwitools

good suggestion.......

where are the other connections located? I think there is another solinoid, but where is it? Is the dash switch known for going bad?

Bob the Fool

bambo2888

get under the truck and make sure the harnesses for the transfer case are firm, like wise, look at your hubs and see if they are wet, get the system pressure checked for a leak.

rabbithound

I have a question related to this .....

When someone's 4wd will not engage, why would you be looking for a vacuum leak.... this is not the first thread I have seen that suggested.... just curious... logically, it would seem that vacuum leak = engaged 4wd right?

asking totally out of ignorance... I am having a problem with mine, but must wait till after the New Year to really dive in and try to fix it ...

bambo2888

im 99% percent sure the vacuum unlocks the hubs into 2wd drive.

pushnf8

I thought the vacuum is what held the truck in 2wd? If there's a leak then the truck would be in 4wd. Not positive though.

redranger1

Yes i believe that vacuum maintains the hubs in the unlocked position, no vacuum allows the hubs to engage.

ford4wd08

check the transfer case motor, ive heard of a few go bad, and yes the vaccum holds the hubs out so its in 2wd, if you get stuck and the soleniod wont do right for some reason and release you could unplug your vaccum lines on the solenoid to make you hubs lock in then put the truck itself in 4x4 if you needed 4x4

bobkyle2

i dont know about this model of truck...but my 98 had a vaccum leak and it would not lock into 4wd...i bought the truck with the 4wd not working and they said the transfer case was bad...and i see the vaccumme line was busted...took it home fixed the line...never had another problem after that...and i used the 4wd almost everyday for a year or so