2-105 warning lamps and fuel sender test

[Jake Collie]

Here's a dumb question, so please go easy on me. How does a person replace a warning lamp? (parking brake, trans oil pressure) Does the red plastic cover come off from the front of the dash or do you have to remove the dash and replace the lamp from the back side?
Also, can I test the fuel tank sending units with an ohmmeter from the sending wires at the gauge to ground (removed from gauge of course) or do I need to test the sending units at the units themselves? The gauge goes to full when I ground the sending lug and goes to empty when I remove the wires from the sending lug. Both tanks are full.
Thanks

 

[MikeO-WI]

I had a non-working fuel gauge on a purchased 2-105 that took a little bit to track down. There is a trick to how the wires are hooked up to make the connection between the two sending units. Someone provided a wiring diagram and I found the wire between the two tanks was missing. Ran a new wire and hooked it correctly and it worked. You might find the posts to my question in a search from mid year last year.

 

[Jake Collie]

Thanks Mike. Will do

 

[rvirgil_KS]

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Page 2 7/8/22 update on 2-105 gauges

 

[MikeO-WI]

I think the last two letters are extra. Just checked to see all my posts.

 

[MikeO-WI]

If I recall correctly, one of the two senders is not grounded and therefore there is a wire needed to run from one sender to the ground on the not grounded sender and then from that sender to the guage. It was a bit odd but I was surprised when I found the post that were used and ran a test or jumper wire. It worked.

 

[random_farmhick]

First thing first, if I remember correctly, the early ones, pre gravity flow, only had a sending unit on the top tank. If that s the case, testing is going to be different than the later ones. So which style do you have?

 

[Jake Collie]

Later style. Both tanks have senders.

 

[MikeO-WI]

Jake, I went out to the farm today and looked at the White 2-105 I worked on this past summer. The wire I ran to the lower tank connected to a blade type post on the outer ring of the sender unit. The post in the center of the sender unit has a wire attached to it but I never really tracked that one down. As best I could determine that wire connected to the frame of the tractor to provide the necessary ground to complete the circuit. As best I can tell, the lower tank is insulated from the frame so there is no direct grounding. Maybe someone with a little bit more knowledge on this can chime in. I can't remember what the connection was at the sender for the upper tank but this wire made it finally work. I have a picture and will try to load it up.

 

[Jake Collie]

Mike - FYI - The wire in your picture with the blade type connector should be an orange wire. It goes from where you have it connected up to the upper fuel tank sender and then on to the fuel gauge. The other wire in your picture should be a black and white wire which goes straight to the fuel gauge. I will have to do some checking on my wires for continuity when it warms up.

 

[random_farmhick]

Well this is what my service bulletin says for what they should test.

 

[Jake Collie]

Great information. Thank You

 

[Woodyw]

Well this is what my service bulletin says for what they should test.

HI , any chance you would have like the .pdf images of these pages so I could Print off ? Thank you !

 

[Jim.ME]

HI , any chance you would have like the .pdf images of these pages so I could Print off ? Thank you !

I use a computer. I just right click on pictures like those and save a copy to my computer. I can then print them off same as any picture. I expect you can download them to your phone or tablet and print them as pictures on those devices.

 

[Woodyw]

Yes , I already did that , just seeing if u had better images , but these will work , thanks for Posting ! I have 2 2-105's one with sealed lower tank and older white has lower tank with cap, kinda wild how senders are in series ?

 

[Jim.ME]

Yes , I already did that , just seeing if u had better images , but these will work , thanks for Posting ! I have 2 2-105's one with sealed lower tank and older white has lower tank with cap, kinda wild how senders are in series ?

You will need to wait to hear from random_farmhick to see if he has pdfs of them, I didn't post those pictures. I just passed on how I save such, in case you hadn't tried that.

 

[random_farmhick]

HI , any chance you would have like the .pdf images of these pages so I could Print off ? Thank you !

I do not have them in pdf form. I just took a picture on my phone and posted it from there on here. My scanner I can't hook up to my laptop either anymore, not sure why. I will try to dig out the bulletin sometime, but I don't think it had the wiring diagrams in it. Now if I remember correctly, the tractors that had the sealed bottom tank, were an isolated ground, meaning that it's rubber insulated from touching the frame. If you have the older style with the cap on the bottom tank, there is only a sending unit on the top tank that is the 33-240 ohm sender. If you have the gravity flow from top to bottom, then you have the sending unit on both tanks. You have the wire that comes from the gauge, to the lower fuel sender, then you have the "ground" wire that comes from the lower sending unit to the top tank sending unit. Then the top sending unit is grounded to the fuel tank, and ultimately the tractor frame. The ground wire on the lower sending unit is shown in Mikes post number 9 above. The spade terminal on the lower tank goes to the ring terminal on the center of the sender on the top tank. Clear as mud?