HELP MY X748 IS DRIVING ME CRAZY

[chiefswood]

HAVE 8 YEAR OLD X748 ULTIMATE JOHN DEERE.
RUNNING PERFECTLY THEN ONE DAY TURN KEY AND DASH PANEL PULSED A FEW TIMES QUICKLY THEN EVERTHTING TOTALLY DEAD....... BUT HAD HEAD AND TAIL LIGHTS
HAVE CHECKED OVER EVERY INCH OF WIRING , ALL INTERLOCK SWITCHES CHECK OUT PERFECT. NEW IGN. SWITCH, NEW PTO SWITCH. NEW BATTERY, NEW VOLTAGE REGULATOR , ALL FUSES GOOD, ALL CABLES 100%AND ALL GROUND WIRES CLEANED AND TIGHTENED.
WHILE TRYING TO FIGURE THINGS OUT IT BY CHANCE STARTED AND RAN PERFECTLY. DASH PERFECTLY NORMAL , CHARGING NORMAL THEN IT JUST STOPPED AS IF TURNED OFF . IT DID THIS 2 TIMES
THEN FROM THERE ON IT HAS BEEN TOTALLY DEAD BUT STILL HAVE HEAD LIGHTS ! TURN KEY TO GLOW AND THEN OVER TO START AND IT IS JUST DEAD IN EVERY POSITION.

FINALLY TOOK IT TO JOHN DEERE DEALER WHO CHECKED IT OUT AGAIN AND WAS STUMPED. FINALLY HE PUT IN A NEW DASH PANEL IN DESPARATION AND THE TRACTOR STARTS AND RUNS NORMALLY.

HOWEVER........................... THE DASH PANEL PULSATES WITH THE PANEL LIGHTS ALL FLASHING ABOUT 2 TIMES A SECOND AND THE GAUGES TEMP AND FUEL BOUNCE ALL OVER THE PLACE.
HAS ANYBODY GOT ANY ANSWERS ON THIS X748 ????????????????????????????????????
THE MECHANIC IS STUMPED AND MY MONEY IS GETTING LOW

THANKYOU

 

[JMER817]

Loose ground?

 

[chiefswood]

ALL GROUNDS ALL CLEANED TIGHTENED AND RE CHECKED FOR CONDUCTIVITY
THANKS FOR REPLY

 

[jenkinsph]

When you say the ignition switch is dead, are you tracing the wiring backwards to the battery to determine the failure point? Do you have a vom to check the wiring?

 

[beenthere]

Why are ALL-CAPS so hard for me to read? My eyes go buggy.. sorry.

 

[jenkinsph]

Reading through your post again this morning I suspect you have a poor connection in one of the supply leads that feeds the ignition circuit. While it may be reading the proper voltage with a meter (which does not load the circuit) it can not allow enough current to flow without a voltage drop. If it were me I would get a wiring diagram and trace the path of the power feed circuit to the ignition switch. I might also try a jumper from the battery to the ignition switch with a fuse added for protection to see if this works. Make sure you can identify which wires supply power to the switch if you are unfamiliar with electrical wiring and trouble shooting it would be best to have someone with experience handle the trouble shooting. Your mechanic may not have enough electrical experience to deal with this problem.

As Beenthere mentioned please turn off all caps.

 

[jymbee]

HAVE 8 YEAR OLD X748 ULTIMATE JOHN DEERE.
RUNNING PERFECTLY THEN ONE DAY TURN KEY AND DASH PANEL PULSED A FEW TIMES QUICKLY THEN EVERTHTING TOTALLY DEAD....... BUT HAD HEAD AND TAIL LIGHTS

Probably not related, but my X748 Ultimate suddenly STOPPED running a while back. Had ran fine up to that point but there were a couple of times when it started to cut off while mowing. But this time it was just DEAD. Thought perhaps it was related to the seat switch somehow as that had been an issue previously. But no, all seemed well there.

A friend helping me finally traced some wires that seemed to be connected to the starting system to the upper side of the right fender. He reached under there and jiggled the wires-- and it started! Have no idea how or why but meant to look into it when I had a chance. That was over a month ago and it's been running fine ever since. Never did try to figure out exactly what was involved (if it ain't broke...).

 

[chiefswood]

Reading through your post again this morning I suspect you have a poor connection in one of the supply leads that feeds the ignition circuit. While it may be reading the proper voltage with a meter (which does not load the circuit) it can not allow enough current to flow without a voltage drop. If it were me I would get a wiring diagram and trace the path of the power feed circuit to the ignition switch. I might also try a jumper from the battery to the ignition switch with a fuse added for protection to see if this works. Make sure you can identify which wires supply power to the switch if you are unfamiliar with electrical wiring and trouble shooting it would be best to have someone with experience handle the trouble shooting. Your mechanic may not have enough electrical experience to deal with this problem.

As Beenthere mentioned please turn off all caps.

Hi jenkinsph,
I think you have some valid ideas. You are right as there may be a connection but so poor that it will not carry enough current to support load with out a drop in voltage.
This may also account for the fluctuation.
Without the wiring diagram the it is very difficult to figure things out.
the power seems to go to the ignition switch and go thru it properly but them it here is where it seems to be the problem.
I cant figure out if there are some I. c. circuits in the dash or relays
I will keep at it as the answer is in there some place.
Many thanks for your help on this. I will keep you posted on out come.

 

[chiefswood]

hi jymbee!
thanks for the hint as the power port[cigar lighter] wiring is right under the right fender and it is not presently working.
There may be some connection to my problem
I did check the fuse in it and it was ok however it was still not working . unfortunately I got side tracked and didn't didn't think this would be related. however it may be !
thanks again

 

[Zebrafive]

Why are ALL-CAPS so hard for me to read? My eyes go buggy.. sorry.

same here, I don't bother if someone post in all caps.