8070 How/Low Power Source

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   I am curious if anyone knows where the power source comes from the high/low transmission switch on a 8000 series Allis. We got the transmission overhauled to the tune of $9,300. I am not going to lie, the transmission was making noises when pulling up a hill before. Now I don't even hear anything from the transmission when pulling something. 
Anyway the high/low wasn't working when we got it back. The shop guy said it worked for him, and thought it was a short of some kind. We tested the toggle switch over the weekend, and no power. I tried to see if the power source came from the fuse panel, the alternator, the key switch... You name it, I can't find where the green wire connects to. As you can see in the picture it goes into the wiring loom. The solenoid only has two wires going to it, which is black and white. 

To sum things up I tapped into the key switch to power the (high/low) toggle switch for the transmission and everything works as it should. I am just curious if anyone knows where the high/low get its power from to power the high/low solenoid. I could not find the power source. 

(I hope I uploaded the pictures correctly.)

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tthams Members Profile Send Private Message Find Members Posts Add to Buddy List Bronze Level Joined: 18 Oct 2020 Location: Denison, Iowa Points: 140	Post Options Post Reply Quote tthams Report Post Thanks(0) Quote Reply Topic: 8070 How/Low Power Source Posted: 22 Mar 2021 at 10:59am
	I am curious if anyone knows where the power source comes from the high/low transmission switch on a 8000 series Allis. We got the transmission overhauled to the tune of $9,300. I am not going to lie, the transmission was making noises when pulling up a hill before. Now I don't even hear anything from the transmission when pulling something. Anyway the high/low wasn't working when we got it back. The shop guy said it worked for him, and thought it was a short of some kind. We tested the toggle switch over the weekend, and no power. I tried to see if the power source came from the fuse panel, the alternator, the key switch... You name it, I can't find where the green wire connects to. As you can see in the picture it goes into the wiring loom. The solenoid only has two wires going to it, which is black and white. To sum things up I tapped into the key switch to power the (high/low) toggle switch for the transmission and everything works as it should. I am just curious if anyone knows where the high/low get its power from to power the high/low solenoid. I could not find the power source. (I hope I uploaded the pictures correctly.)

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Lynn Marshall Members Profile Send Private Message Find Members Posts Add to Buddy List Orange Level Access Joined: 13 Sep 2009 Location: Dana, Iowa Points: 2355	Post Options Post Reply Quote Lynn Marshall Report Post Thanks(0) Quote Reply Posted: 22 Mar 2021 at 11:29am
	Early tractors used fuses,later tractors had circuit breakers. I believe that there's a decal on that one brown panel that shows the purpose for each fuse or breaker. Owners manual has a detailed wiring diagram in it.

tthams Members Profile Send Private Message Find Members Posts Add to Buddy List Bronze Level Joined: 18 Oct 2020 Location: Denison, Iowa Points: 140	Post Options Post Reply Quote tthams Report Post Thanks(0) Quote Reply Posted: 22 Mar 2021 at 11:58am
	Thanks for the reply. I'll have to check again sometime. I looked the circuit breakers over. I must have missed the sticker on the brown panel explaining each breaker. I couldn't even find one with a green wire going to it.

Ron(AB) Members Profile Send Private Message Find Members Posts Add to Buddy List Orange Level Joined: 27 Dec 2009 Location: Alberta Points: 959	Post Options Post Reply Quote Ron(AB) Report Post Thanks(0) Quote Reply Posted: 22 Mar 2021 at 2:25pm
	Check the clutch pedal safety start switch. I believe it has to work before the hi/low switch will work. It could be stuck...need of replacement, etc.
	405, 7000, 7050, 8050, 8070, L3, 2300 & 2600 disk

tthams Members Profile Send Private Message Find Members Posts Add to Buddy List Bronze Level Joined: 18 Oct 2020 Location: Denison, Iowa Points: 140	Post Options Post Reply Quote tthams Report Post Thanks(0) Quote Reply Posted: 22 Mar 2021 at 3:17pm
	That does make sense. Prior to the transmission going bad there would be days where the transmission would shift great, and then later in the day it would not want to shift for awhile, and then it would start to work again. Maybe a failing sensor switch? I will have to check and see if I can start the tractor now without pressing in the clutch. Stepping in the clutch has always been the normal for me.

Lynn Marshall Members Profile Send Private Message Find Members Posts Add to Buddy List Orange Level Access Joined: 13 Sep 2009 Location: Dana, Iowa Points: 2355	Post Options Post Reply Quote Lynn Marshall Report Post Thanks(0) Quote Reply Posted: 22 Mar 2021 at 10:14pm
	There is a clutch safety start switch in that area, but it doesn't have anything to do with the power director part. There is another switch in that same area that is used as a kick down to the low side of the power director every time that the clutch is depressed. That is so you always start the load in the low side and then you can always shift up. The low side has more plates and is made for inching a load also. I believe that those switches are identical. If that switch was stuck, you wouldn't be able to shift to the high side. When you look at it again, I think you'll see which switch does what. There's also a relay there by the fuse panel that is for the power director. It could be bad.

tthams Members Profile Send Private Message Find Members Posts Add to Buddy List Bronze Level Joined: 18 Oct 2020 Location: Denison, Iowa Points: 140	Post Options Post Reply Quote tthams Report Post Thanks(0) Quote Reply Posted: 23 Mar 2021 at 5:51am
	That makes perfect sense. Thanks everyone for helping me figure this out, and look at it from a different approach. I will be calling AGCO today to pick up parts.