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Erratic Tach

Yahoo Message Number: 97273
My tach started reading 1,000 to 2,000 too high. Sometimes the needle jumped around, other times it showed RPM changes correctly but way too high. I replaced the tach and the new one does exactly the same thing. Any suggestions?

Jim Coshow

2005 Inspire 51501 Cat C9

Re: Erratic Tach

Reply #1
Yahoo Message Number: 97275
Jim,

Check with Kevin Waite. I seen him about a month ago and he said he had a couple of tachs on hand. His # is 541-953-6162. I'm sure he can help. I had to replace mine a couple years ago, not to hard to do.


Jock Vargo

2005 Inspire
51428

Re: Erratic Tach

Reply #2
Yahoo Message Number: 97277
Jim,

I believe your alternator is on the way out. The tach gets its signal from the alternator. When replacing be very careful that the replacement alternator is the right one. Some have an internal voltage regulator and some have an external. Whichever one is used may affect the wiring to get it right.
Lyle Wetherholt
04 Intrigue 11740

Re: Erratic Tach

Reply #3
Yahoo Message Number: 97278
Jim, before you do anything else, check the ground connection behind the tach and beneath the instrument pod. Cleaning it fixed my erratic tach.

Jay
51457