Hello everyone! I've been having trouble with my Deere 750C series II speed control. It just started a couple days ago, I was operating and speed suddenly went to 1 on its on. I turned it off let it sit a while and it worked fine on start up, but continued to do it off and on the rest of the day, at one time doing the opposite and running up to 3 and sticking but back to 1 when code flashed. I was getting the codes F654 and F658 randomly. Took the speed switch out of the joystick to examine/clean it and it worked fine for a whole day after. Yesterday it went back to 1 speed and hasn't moved no matter what. I've checked all the visible wires for shorts etc. and I don't see anything. While I was working on it, it did work fine for a minute but then back to 1 with code. I've listed the codes below. Any help is appreciated! F654: B12 (1/2 mph) Transmission Speed Control Switch / Signal Voltage Under 0.5V / F658: B9 Decelerator Sensor and B12 Trans. Speed Control Sensor (Single Lever Steer) / Excitation Short to Ground
I forgot to mention that my Deere dealer seems to think its the speed control switch, which is $700.....I'm just not sure it is and wouldn't want to buy one plug it in and fry it too!
I think it throws both of those codes any time the TCU sees less than .5v coming back from the SIG. I would back probe the signal wire from the switch and read the voltage. Also make sure there is a good steady 5v going to the switch. If that is good go back and check the signal wire at the TCU and see if it is lower than what's coming out of the switch. You may have a harness issue.
Thanks for the reply! Would you know which wire is which going to the switch? They are all marked and one yellow with green stripe.
Sorry, not off the top of my head.
So I've got an electrical gremlin that has moved from my dump truck to the dozer. Fun FUn FUn.......
Had a buddy help run a few test with a multimeter and discovered that the push buttons on the speed control switch were shorting out from time to time. Pulled the switch out took solder gun heated the solder to remove old buttons and found new ones on internet for $3.85 each. Should be in Tuesday and we'll solder them back in and hopefully be in business. My local dealer wanted $700 bucks for this switch. Find someone who's good with a solder gun and familiar with circuit boards and you can rebuild this whole switch for $20.
This is a picture of it all put together in case anyone is wondering.
I'm curious where you got the switches from.
The link is to the button that was specific for my application. Most of these parts will have numbers on them somewhere to reference too. This place has about anything you'll need in electronic parts. http://www.digikey.com/product-detail/en/K12C 1 5N/401-1159-ND/417544
Great, Thank you.
I don't have anything new enough to have electronics or switches like that, but that's sure some good information to have. Might come in handy someday, thanks for sharing!
Glad to be able and share! Give back when I can, sure have received my share of help. I'm curious, what 69 do you have. My father and I have been trying to track down one he owned for years. His was a red, white top, white houndstooth seats, auto, all gauges, ac, etc. 396/375HP. Ruled the road in the day!
That's a good looking car! I would like to have one like that myself. Mine is strictly a drag car, the shell is about the only thing left of the original car. I think it had been a drag car for a long time before I got it, originally white or yellow I believe.
So did the buttons work?