Perfect Pass beeping and gauges cutting out

[dtmoke]

My 03 22V has electrical issues too. I'll be checking grounds this weekend. While winterizing I noticed my engine ground has some corrosion that needs cleaned up.

Where are the other grounds up near helm?

[IDBoating]

Thought I'd share something related to this grounding question.

I own a Case 580SK loader/backhoe. Recently the engine refused to start, and a bunch of other electrical gremlims crawled in too. Weirdest one: I could turn on the key and the dash would light up, but as soon as I turned on ANY other electrical load (one set of lights, the horn, anything) everything would die and I could hear the cab relay chattering. Relays chatter when their coil voltage is too low.

Long story shortened: The last piece of the puzzle turned out to be the braided ground strap on the battery's negative terminal. I don't know if it was the factory or the original owner (I'm #2), but someone attached the braid's nice big lug to a bolt that already had a nut on it... and put a toothed lockwasher on the bolt first, then the lug, then another washer, then a nut. So all of the current from the battery was passing through the points on those two lockwashers! And they were nice and rusty.

The voltage drop across that braid, with just one set of lights on (~10A current flow), was SIX VOLTS. Turn off the lights and the voltage popped back up. No wonder the relay was chattering... when off its coil saw 12V, so the relay turned on, which put 10A of load on the battery, which dropped the voltage to 6V, which turned off the relay, which removed the 10A load, so the voltage popped back up to 12V, so the relay turned on again... lather rinse repeat.

Doing the math, that means there was roughly 0.6 ohm at that lug. If you put a "continuity meter" on that, it will probably say "Yep, you have continuity!" and you'll move on, entirely missing the problem. 600mOhms of resistance doesn't sound like much. But when you're dealing with tens or hundreds of amps (as in a 12V system), the voltage losses add up FAST. Moral of the story: You MUST minimize resistance in your ground connections. The bigger the connection, the more important this is.

BTW, my solution was to remove all hardware from that bolt down to the frame itself. Then I used my Dremel and a wire wheel to burn off the paint on the frame around the bolt and clean up the lug. Then I reassembled things, but in this order: Frame - lug - lockwasher - nut. Now the entire surface area of the lug is in direct contact with bare frame metal, crushed against it with a nut and lockwasher, and the lockwasher is being used the proper way - to prevent the nut from backing off, not inserting resistance in the current path! Voltage drop is now unmeasureable even with my nice Fluke meter, and everything runs perfectly. I slathered the lug-to-frame connection with Vaseline to prevent moisture from creeping in there again.

Keep those grounds CLEAN!

[mikemcclain8]

In my 2005 22i, I had a similar issue. Turned out to be the ground that ran up to the tach. The nut was loose so when I'd go over wakes, it would beep, the gauge would jump, etc. Tightened up that screw and all has been good.