wow ,thanx bob for the quik reply ,,. I do have a parts book and op manual , my 750 was one of the very last gray cab 750s built ,.when it comes to electronix , I am not as good as most folx ,,. ,. more than likely it is one or both of those solenoids relays under the rite panel,,.who knows it mite be a common automotive relay ,,. not lookin forward to paying agcos price for something that mite not be broke ,.. usually ,, at 1st startup,.everything worx..tach lites up ,I hear a relay clik regardless of whether I have electric or not , , then after a hour or so,.i loose all power to the tach , hydraulix and my cab fan , most times if I shut off the motor for a minute all comes back on and worx fine ,. I suspected my ignition switch ,so I got a new one ,,. and all was fine for a month or two,,. I have found that swappin ignition switches would restore electric every time ,,. but not lately,.the problem is getting worse . when roading the electronix usually loose power after a couple miles , not good when ya get to the field and you want to kik it in gear and start combining . and the durn head is up with a 4 hour erection ,.. LOl ,. if I wanted to road the combine home ,,.it would be nice to be able to overide a switch and make it lift ... but from what I am learning it really is easier start replacing solenoids and relays ,. than to crosswire a solenoid switch and risk messing up more delicate equipment ,.