John Deere 997 Seat Safety Not Working

[StarTech]

That's okay as I will DL a copy of the TM2259 for my shop too since I don't have that copy here. GFP hasn't responded to me yet.

Update

And I just looked over that TM2259 and it appears to be the correct manual. Tnx for the TM PN.

Partial seat switch circuit diagram. Boy I haven't seen a PNP transistor used in a long time.

Remove the module and temporary jumper green wires 640 and 641 together. This will bypass the time delay module for test purposes.

 

[Auto Doc's]

OK, the rain finally stopped and I got to dig a little deeper. I found a picture of a 2x2 pin configuration delay module that showed wire colors and I checked resistance reading that Kenbu posted on my 1x4 pin configuration delay module. They were very similar readings as shown in the attached pic so I don't think I have a bad delay module. More digging ensued.
Aha!, I found some more wire modification shenanigans put in place by a previous owner. Under the control panel, i found another jumper that picked up power off of one lead coming from to the ignition switch and fed it to a solenoid on the hydraulics pump. The other leg of the plug at the solenoid was jumpered to a wire on the PTO switch. Again, no idea why someone put this and the other jumper (delay module to fuel cutoff solenoid) in place. Not sure if the previous owner was a genius fixing a problem I haven't found yet or a hack just finding power/ground somewhere and using it willy-nilly to get something to work rather than fixing what was really wrong. Use of these blue piggyback splice connectors probably eliminates the genius probability.
I think I found the service manual on Ebay for this mower that should have schematics I can use to figure it out. I'll write the seller to confirm it covers my particular mower.
The saga continues...!

Hello J.,

When I see tap splices like that, it spells "rednecks and beer" around my area. Those things should be outlawed. Small utility trailer companies use them by the bags full, they are nothing but trouble.

Your test measurements are not terribly off, so I suggest you correct all the creative wire passing attempts and restore it back to original before you condemn the delay module.

Marine butt slices with sealant in them are ideal for this kind of repair. Wiring can be tedious, but if done correctly, it will last you for many years.

Last item I will mention is to remove all the cable ties that appear to be overtightened. That causes broken wire strands inside the wire insulation.

 

[jshep1102]

That's okay as I will DL a copy of the TM2259 for my shop too since I don't have that copy here. GFP hasn't responded to me yet.

Update

And I just looked over that TM2259 and it appears to be the correct manual. Tnx for the TM PN.

Partial seat switch circuit diagram. Boy I haven't seen a PNP transistor used in a long time.
View attachment 72153
Remove the module and temporary jumper green wires 640 and 641 together. This will bypass the time delay module for test purposes.

OK, I've run out of daylight but we're getting closer (I think). Still weird response, this is what I have:
1. With key in "RUN" position, I have 12+VDC on yellow 509 at seat delay module (expected)
2. With key in "RUN", I do not have any voltage at yellow 510 at the seat switch (unexpected)
3. With key in "RUN", I do not have any voltage on green 641 at K2 seat relay (Unexpected)
4. However, in "RUN", I do have voltage at green 640 at delay module (unexpected) even with the seat switch unplugged. Obviously, i'm picking up 12V on green 640 somewhere but I haven't found out where yet. I'm guessing somewhere, the previous owner jumped 510 yellow to 640 green
5. I have a 5th wire attached to 87A terminal on the seat relay. Is it possible this partial schematic isn't applicable to my mower.

I like a good electrical troubleshooting problem. I got one here for sure. Thanks for hanging in there with me.

 

[StarTech]

sorry i posted an earlier partial for before SN 020001

this is for the (S.N. 020001-050000) that 5th wire should be a pink wire [658].

 

[StarTech]

Sorry the attached is not super clear but even the service manual image are not very clear. But I spliced together multiple [6 pages] to give overall idea how this nightmare wiring is done.