JD 2150 Ignition Switch Wiring

Looking for some help replacing a bad ignition switch on a 1985 JD 2150 Tractor. There was 5 wires going to the switch and I have identified only the BAT cable. The old defection ignition switch has no labels on any of the pins. The old switch had 6 pins but not all were being used. The new ignition switch purchase is clearly marked BATT/IGN/ACC/GRD/ST. The at attached pictures shows only the old switch. The PAT NO. Engraved on this switch is a standard 3497644. All of the switches I found on the internet with that number do not have 6 pins that look like this nor do they have their terminals ID as per what we have on the new switched purchased! Is there anyone that can look at the back picture of the switch I have posted from behind that have no wires attached to it and identify the terminals in this old switch in order for us to re-attached the wiring correctly to the new switch which is properly labelled? Thanking you in advance for your help. PS - I have the service manual for the JD 2150 and the Main Ignition Switch shown in the manual only has 5 terminals on it and looks completely different.

What is the switch you purchased? When I look at AR58126 (the part number of the switch in the JD 2150 parts catalog) switches online, I see switches with 6 spades. The cast number on the switch body is likely just an identification number the switch manufacturer used for the metal body, and meaningless for identification in this case.

You should be able to use the wiring diagram in your service manual to identify the wires and get them on the proper terminals of the new switch.

This post was edited by Jim.ME on 04/21/2023 at 04:02 am.

Hello Gb welcome to YT! I see a diamond symbol on
the one plug. Do the others have different symbols?
That may be the key to where they go. For me if all
else failed I would use a short jumper wire in the red
one if it is the power wire. Then jump it over to the
others to see what the do and connect accordingly. I
am sure with a wiring diagram it can be figured out.

Thanks for the suggestions. Apart from the new switch we figured out the main issue was a bad ground connection from the batteries to the ground on the alternator frame. Once we got the ground connections sanded and cleaned and also cleaned all battery posts and terminals we focused on the new switch. Within 15 minutes, we had the wiring figured out and the new switch working perfectly. Thanks again for trying to help us.