40th Anniversary salvage rebuild

[simps80]

Pin 7 mod or nah?

 

[HDavis]

Pin 7 mod or nah?

I did not do the Pin 7 mod yet.

 

[simps80]

Then the switch is ineffectual to override default 4 low locking of cdl should work regardless

So are you saying cdl doesn’t engage in default 4 low?

 

[HDavis]

Then the switch is ineffectual to override default 4 low locking of cdl should work regardless

So are you saying cdl doesn’t engage in default 4 low?

Thats right, I got it to engage in 4 low last week. I know it's not the bulb because it was working fine then and yesterday when I engaged 4 low, I didn't feel binding like I typically would in low range.

 

[nakman]

Odd that it would lock up a week ago…

 

[HDavis]

Odd that it would lock up a week ago…

Agreed, It's got me perplexed. I am glad I took a photo, otherwise I would be questioning my own memory.

 

[Basaltfj40]

Did you check the fuse? My 80 just blew the 30amp fuse for the lockers a couple weeks ago.

 

[HDavis]

Did you check the fuse? My 80 just blew the 30amp fuse for the lockers a couple weeks ago.

I did check the fuse but I might swap a new one in there just in case.

 

[HDavis]

I've driven the 80 to work all week for the total of 200 miles. On the way home on the first day, I got a trouble code P0401. Thanks to my Ultra Gauge I was able to read it immediately and determine what the code was. So, I will need to diagnose what the culprit of that code. Yesterday I pulled the center diff lock sensor and tested it and determined it to be good. I am going to do the 7pin mod next and see if it switches on with that and go from there.

 

[ODY80]

P0401 is related to the EGR i believe. Been digging through this one on mud if it helps. https://forum.ih8mud.com/threads/p0401-defeated-with-pics.363575/

 

[simps80]

One of the best threads on here
Authoritative

Same condition I know why for me
Y pipe is cracked wreaking intermittent havoc

Haven’t fixed it clear code pass emissions rinse repeat

Oh joy, P0401 is back... (and how 80's fail emissions)

So on Wednesday night driving home my CEL came on. Pulled the code last night and yup, PO401. so I cleared it, driving the 80 again today and it hasn't come back on yet. I have 2 theories: one is I am pretty sure I've got an exhaust leak, maybe multiple. Occasionally when I start the truck I...

risingsun4x4club.org

 

[HDavis]

One of the best threads on here
Authoritative

Same condition I know why for me
Y pipe is cracked wreaking intermittent havoc

Haven’t fixed it clear code pass emissions rinse repeat

Oh joy, P0401 is back... (and how 80's fail emissions)

So on Wednesday night driving home my CEL came on. Pulled the code last night and yup, PO401. so I cleared it, driving the 80 again today and it hasn't come back on yet. I have 2 theories: one is I am pretty sure I've got an exhaust leak, maybe multiple. Occasionally when I start the truck I...

risingsun4x4club.org

I suspect my y-pipe has a leak somewhere. Someone has tried to fix it in the past and the repair looks good, however, I think I can hear a leak when standing on the passenger side while its running.

 

[subzali]

On two different trucks my P0401 has been a bad EGR VSV. But it could be any number of things as seen in that mud thread.

 

[HDavis]

On two different trucks my P0401 has been a bad EGR VSV. But it could be any number of things as seen in that mud thread.

I ordered the Dorman one from amazon thinking that if it didn't solve the problem, I would return it. It seems to be the simplest solution to try first. fingers crossed that's it.

 

[HDavis]

I was able to dig into the diff lock issues and tested the diff lock for resistance, and it tested fine. I then pulled the relay and started testing for continuity and resistance per the fsm. I didn't` do the tests where you supply power to the relay, but I definitely was not getting continuity between terminals 1-2, 2 -4, and 6-7. So, I suspect that the relay has bit the dust in the last two weeks. What are the odds??

Also, has anyone ever used a 100 series relay in their 80 series? I ask because they look very much the same with slightly different part numbers and I could pull the one from the 100 to see if my theory of mine being bad is correct.

 

[Hulk]

I am going to do the 7pin mod next and see if it switches on with that and go from there.

I've never done the pin 7 mod. I do have the center diff lock switch.

 

[HDavis]

I've never done the pin 7 mod. I do have the center diff lock switch.

I did the 7pin mod when I was checking for resistance and continuity and the diff didn't lock after the mod.

 

[Stuckinthe80s]

I was able to dig into the diff lock issues and tested the diff lock for resistance, and it tested fine. I then pulled the relay and started testing for continuity and resistance per the fsm. I didn't` do the tests where you supply power to the relay, but I definitely was not getting continuity between terminals 1-2, 2 -4, and 6-7. So, I suspect that the relay has bit the dust in the last two weeks. What are the odds??

Also, has anyone ever used a 100 series relay in their 80 series? I ask because they look very much the same with slightly different part numbers and I could pull the one from the 100 to see if my theory of mine being bad is correct.

I know the plug works for both the 80 and 100 but I haven’t tested for functionality. I do think I had to change the wiring around but I think it was just because I was using 1992 wiring to interface with 1999 drivetrain

 

[HDavis]

I know the plug works for both the 80 and 100 but I haven’t tested for functionality. I do think I had to change the wiring around but I think it was just because I was using 1992 wiring to interface with 1999 drivetrain

I pulled the two apart to see how different they were. The circuiting is very similar but I just don't feel confident enough to plug it in to see. I ran the same continuity tests and it tested the same as the 80 relay so now I am questioning if the 80 relay is good or bad.

 

[Stuckinthe80s]

This is from a 97 LX450 EWD, which I would think would be the same but I don't see a pin 6 on the relay itself. If anything, Toyota uses the same wiring principles for years so you may be able to derive what you're looking for from this schematic.

Here is the schematic from a 1999 EWD (just because...):