IH 1440 keyswitch relay problems?

[pratt1]

I'm working on lights and turning the key to the on position without starting the machine, to test them. I hear the fuel pump and sometimes it stops. The lights sometimes come on and sometimes not. Could it be the relay?(40 year old machine)

 

[Petal to the Metal]

If it's a "sometimes" problem then it could be the chip (the brain). I'm no expert, but that's what's been wrong when I've had "sometimes" problems in the past. I hope you'll let us know once you get it fixed.