SOLVED! 4WD flashing.

I've taken a break with my Tundra's 4WD issue. Im the OP.
I definitely need a new transfer case actuator. The plastic housing is cracked a the screws that hold it to the actuator body are corroded on. There's only 3 or 4 bolts that attach the body to the transfer case. I need to see if the 3 screws for the small cover plate will come off. They might be rusted on too. I'll cut them off since I am replacing the housing. I just need to remove the small gear inder the cover so I can then pull the body. I won't replace the shift rod inside the transfer case but that is a big job. I bought an aftermarket rear actuator. Im hoping i can separate the actuator assembly from the shaft that it came with and attach the actiator to the original shaft thats in the transfer case. I have no idea if this will work but I'll assume the two shafts are identical and it will work. Then I need to take a look at the front ADD. I had it apart and I doubt I have in timed correctly. Similar situation as what Papoajohn 777 described. The electric wiring was damaged but I replaced the damaged piecr with a new OEM harness. The issue now is that its 90 degrees in the shade. I'll get to it soon. Pappajohn, check that the wires at the both actuators a good. Mine were damaged at both ends. Also check all wires going to the 4Hi and 4LO sensors, which are located about the rear actuator. One of the 2 wires connecting to the LO sensors were broken.

 

shifty, I did watch that video and was hoping I could see how the contacts traveled across the cap, but saw that the transfer case ADD is competly different relating to the front axlw ADD. I have done most of the steps that were mentioned excecpt the driving and reversing to see if it would loosen up the ADD on the Tansfer case.. RIght now I am not sure how my transfer case ADD and the lo and hi sensors fit into my issue,, I just want to get the Front axle ADD back together on the differential and have it synced with the transfer case thanks for the advice jr

 

Ah. Yeah, that small but important detail went WHOOSH right over my head

 

Update on my ADD issue. I put the mechanical part of the actuator back on the front differential, and tried to engage the front axle by using the gear and shaft that has a gear on it that engages the rod that moves the shifting fork/yoke. I got the truck up on jack stands and and tried to manually move the collar that slides back and forth in the dirrerential housing. I could not get the axle to engage , which probable means that I never got the fork lined up in the sliding collar, or my front axle is bad.
So off comes the actuator and I slide the collar back and forth with my fingers and I can get the axle to enbage.. I know the transfer case is in 4 wheel drive because I had it in gear, running up on jacks and could see the front input shaft spinning.. I tried several time smacking it with a rubbber mallet as the truck was running in gear , and could not get any response from the rear actuator.. I still am not getting any sign of dc voltage frome any port in the front wiring harness. I will next try to remove that harness and test it for continuity.
I am going to make a gasket for the front ADD so I dont have to play around with messy and sticky gasket maker. I have only found one fuse marked 4 wh in the cab.. Does any one know if there is any other fuses or relays that apply to the 4 wh drive system?
Once I check the harness and wiring around the 4 wh hi and lo sensors, I think I will break down and buy one of the discounted ADDs just to deal with the alignment issue. At least then, that will take a lot of pressure, off the project. I can pull it apart to check the alignment and set up my original restored one so I will have a backup. If I can get power to a new ADD and I see it that cures the flashing light issue and posibily returns the transfer case back to 2 wheel drive , I will be a very happy Tundra owner
If it wont shift back into 2 wheel, I will try to remove the rear ADD and see if that motor is functioning by manually powering it. If that motor is bad, then that might be one of the main trouble causers.. 2 bad ADDs If it tests good, then it could point to the ECU..
I will post another update after I test my wiring and the transfer case ADD. I think I will create a video doing the alignment and even restoring the ADD motors. I did the front one and it was not really not that bad. Getting the brushes back into place was the worse part. ANy suggestions and comments are alway welcome.. Shalom pj fron Auburn

 

My Update: New transfer case actuator works fine. In 2WD, no flashing lights and the front axle is unlocked. If I press for 4Hi, the actuator responds and locks up the front drive shaft. However the lights is flashing and there's no response from the ADD front actuator. I plugged in a new ADD actuator and it didn't respond either. I'm glad I decided to test it by plugging in the connector. It would of been very disappointing to install the new one only to find out it's not getting any power. Decided to test the connectors for both actuator for continuity to the 4WD ECU connector. I was able to verify continuity for each wire on the transfer case connector and the 4WD and 4Lo switches. I checked the ADD connector and wasn't able to confirm continuity between gray wire on #3 of the connector and #19, which becomes a green/black with at a connection with gray #3. I was hot today and I did 4 hours of troubleshooting and checking wires. Had to call it a day. So the question is...why isn't the ADD actuator getting any power when the 4WD button is pressed? There is absolutely nothing; no clicks, buzz, movement. It's dead. I need to check again there's no #3 to #19 continuity and if so, I'll track down the connector where get #3 connects to become GRN/BLK going to #19 of the ECU. #19 is connection point marked "ADD" on the diagram. (I attached a diagram for a 2002 model but my Tundra is an '04. If anyone has the '04 diagram, I'd appreciate if the can confirm the #3 to #19 wire is the same for both model year---my Tundra is a DC and they weren't available in '02. Thx.

 

As mentioned on page 1 post #24, EWD's can be had for an 04 and other years at the link below.

This link ---> Ultimate TUNDRA Wiring Diagrams Collection | Toyota Tundra Forum (tundras.com)

Also in that post was a pdf file that is the appropriate EWD pages for an 04 DC 4WD....4WD flashing. both actuators ok

 

Thanks BubbaW!

 

SOLVED! (Finally!!!) So it turns out the small electric harness that attaches to the front differential actuator was shot. Fortunately Toyota had that small section available so I replaced it. Then there were issues with the wiring attached to the 4hi and 4lo switches, that are attached to the transfer case actuator. Next, 8 of the wires attached to the 4wd ECU were cut or had the sheathing trimmed off so I fixed all that. I checked continuity for all wires going to both actuators, both switches and ecu for those wires that connected to the ECU. I cleaned up the front actuator but had a difficult time putting it together because I wasn't sure of the timing of the internal rotary gear. However, the transfer case actuator was beyond salvaging. I bought a cheap actuator instead of OEM since I didnt want to dig myself to far into the hole without knowing the outcome. It turned out ok but I didnt use the shift rod that came with the actuator, since I would have to take the TC apart to use it. Instead I used the original shift rod abd attached the cheapo actuator body to it. I had to fanagle a bit to get the rod timed with the actuator gear, but I finally got both actuators timed with eachother and 4WD is working smooth. I can't say I enjoyed the project since it was a bictxx..but I'm glad it worked out. Tundra is an '04 DC with 233k miles. When I bought it 4 years ago I saw the prior owner (this was an auction purchase for me) had damaged the TC and declined Toyotas $4,200 repair quote. Apparently a bootleg repair was done and that is why many wires were cut and poorly spliced together. I got 3 years of good 4wd service but the last year issues started up until 4wd finally crapped out. Thanks to all that responded and helped me out.