I was wondering if anyone knows where the tach feed is on the engine. I have been having problems with the tach intermittently going off and on. Sometimes it quits while running and sometimes it never comes on when cranked. Then usually after 2-10 min of not working it starts working again. Anyone got some ideas? Oh and i took the gauge panel out and wiggled everything behind the tach and nothing changed.
Should be off the aultinator. see if the connections are dirty?
I had this same problem with my 98 series II and found it was because some of the bulbs were out in the instrument panel. I think they were the oil pressure and the parking brake lights. It has to dowith the ground in the circuit that is tied in with the alternator.
The wire that feed the signal to the tach is the "W" terminal on the alternator. Get a volt meter...set the meter to test AC current. Remove the wire(yellow) from the "W" terminal at the alternator. Touch the positive lead to the "W" terminal at the alternator and the black lead to the alternator housing. Start the machine.....you should see 8 volts AC. If not... the alternator is the problem. If you see 8 volts AC at the alternator remove the test leads and reinstall the wire. Now remove the dash and test for power there. If there is not 8 volts at the dash..the wire is the problem. If the wire is the problem just run a new wire from the W terminal at the alternator to the terminal in the dash.
tack problems NWH - You solved my problems with gauge cluster and alt. All I had to do was clean all contact points with the bulbs and suckets. Everything is working now. Why, I don't have a clue!!
Tachometer problem: 1998 Case 590sl My newly acquired Case 1998 590sl series 2 was having all kind of electrical problems: Wouldn't hold a charge in the two batteries, the tach wouldn't budge off of 1100 rpms, very few of the instrument panel lamps would light. I started with the battery problem. Traced all wiring from source to destination. Looked for the usual culprits. Two problems were discovered: 1) the two external power outlets near the instrument panel. They were severely rusted up and unusable... disconnected and discarded. And, 2) the fuse block and fuses were badly corroded. Cleaned up the block and replaced some of the fuses. But nothing that should have drained the batteries when the ignition was turned off. Ahah, the ignitions switch. Hard to insert the key and wouldn't turn smoothly once the key was into position... more corrosion. Cleaned and lubricated. Battery problem solved. Did and internet search for Case 590 tach problem. This thread held the solution. I used the continuity light to trace all routing pathways on the thin plastic sheet on the back of the instrument cluster. I used some very fine sand paper and small pattern maker files to clean up all electrical contacts. I found that the lamp receptacles had made small depressions in the copper of the routing sheet. Over the years dust and moisture had accumulated in these spots and reduced those contact points to nil. My suggestion is to clean these contact points until they shine like a new penny. In fact I cleaned every contact point in that system. Any time the electrical pathway was interrupted with a contact point it got cleaned. The result was a smooth operating tachometer and lamps that light up as designed. As a new member of this forum, I want to thank Heavy Equipment and the members who help us keep the beasts running.