KW starter issue

Hope you have that worked out but we have not heard back.
I will share a similar problem and everything is easier with pictures, right? When I look at the picture it is still a snake pit. Looks much better after I pressure washed

Hope you have that worked out but we have not heard back. A picture is worth a thousand words but this is probably a bad example. This is a two battery 12 - 24 system with a series pairilel switch. It is right behind the voltmeter. The red voltmeter lead was connected, pushed hard, on to the ground terminal of the terminating ground battery. Not the cable end but the battery stud itself. The other voltmeter lead is attached to a jumper wire and is on the face of the meter for illustration. The other end of the jumper wire is connected to the ground stud on the starter. Other end of where this wire goes. It registered 4 volts when the starter was engaged Went from the end studs to cable ends and worked back to the battery disconnect switch. The new one has the red lever on it and the old one is to the right. It is broken open and note the burt spot of copper on the right side.
You have to overlook the snake pit and check the circuits one by one.

 

0.5 volts is allowed on battery cables by the book. Have seen many with 0.75 still work file.