The dreaded 4 hi blinking light

This seems to be a common theme. I use my 4wd all the time( part time farmer) but all of the sudden the other week it would not engage. The 4Hi drive light would blink with the dial turned but no luck. Now even with the dial in 2wd as soon as I start my truck the 4Hi light is blinking. There seems to be a lot of conflicting posts, I see some things saying that the ADD is vacuum operated but from what I can see it is all electrical. I am not hearing my transfer case engage, engages first from what I have read. I have checked all the plugs- very clean, fuse act. Is it possible that the 4wd ECU is faulty or that the ADD switch is stuck? I lost my fuel pump ECU earlier this year, that was easy to diagnose. This not so much!!! Any help would be greatly appreciated. I plan on pulling the ADD this weekend and powering the motor leads to see if it moves but I don't want to screw with the transfer case actuator until I have tried everything else

 

Mine like many others was rusted to the point where the motor wouldn't spin. Freed it up with 12volts and some WD-40. The vacuum line on top of the actuator leaks water into the actuator itself.

 

I took a pretty close look at the vacuum line, which I have read is a breather, looks intake with no cracks. I have not plugged a reader in yet. There are not any faults on the dash but I really don't know if it would have one being that this is not an engine fault. This is the second electrical headache that I have had since having the frame replaced last spring.

 

Meant the line is intact not intake. My brain is going to mush trying to figure this out. I put 600# of tube sand in the back yesterday so I could move. Good thing, I live in central NY and we got about 8" of lake affect snow yesterday. Back to the bad ole days of 2 wheel peel !!!!!! HA HA HA Giggle Giggle what fun!

 

I had Haley Toyota replace the frame under Class Action Suit on my 2005 Tacoma AC/TRD Off-Road that I had before getting my Tundra. I did not use the 4-Low for over a year (never tried it, I should have!). When I went to use it it would not engage. I took it to Haley Toyota and they checked it, they said they were losing power from the glove box area connection to the Park/Neutral Switch. I told them it had to be something that they did because of pulling the frame. We went round and round but they ended up screwing me. They ran another wire, and charged me $600. I will NEVER go back to them! Consumer Beware!

 

Thought I would post an update. Got my truck up on a lift this weekend, ran a scan- no codes. I had the key on and the 4Hi engaged on the dial and I could hear the shifter motor making noise. It is definitely locked up. The crews are so rotted I couldn't even get the cover off. Have a new one on order, going to drop the transfer case later this week.

 

Replaced the shifter last week. Not a bad job if you have a lift. 45 min to pull it, used a tranny jack to pull it out put back in by hand. Easier to line up, not too bad with 2 guys. Got the OEM shifter on E-bay for $560 with tax. Direction suggest replacing the front seal. flange o-ring and nut. The nut has a crush collar that is peened into a key way that can be opened up with a small pin punch. The idiots at my local stealership gave me the back seal, about 20 thousands smaller O.D. so I put the old seal back in. It can be replaced in the truck so I figured it is better than waiting 3 days for the new one. The shifter comes with very good directions, but did not mention that you have to pull the rear output flange also to get the shifter out. Truck was a little weird at first when we got it back together because the shifter was in the 4lo position when it was installed. Had to put it in gear and let it shift up to sync the transfer case, finally shifted to 2hi and everything is working well. Besides for the delay to call and yell at my local dealer and taking a lunch break the whole job took a total of about 4 hours. It was a fairly easy job for two guys that are used to turning a wrench. I flipped my friend a couple of hondos for the use of his shop and tools. I am into the entire repair for about $800; a hell of a lot better than the $2500 that I have heard the Dealers want!!!!