Grounding Problem

[parker1700]

I have a 1995 Parker 1700CC w/ Evinrude 88SPL. I recently noticed that all my gauges( tach, volt, fuel, trim )were either fluctuating or not working at all. I intitially replaced the volt meter which was reading incorrectly (showed 18 volts with just ignition turned on) and had the same problem with the new volt meter. A local repair shop told I needed all new gauges to correct the problem but I think it may be a bad ground. Has anyone else had this problem?

 

[Silvertip]

Re: Grounding Problem

Fluctuating gauges are almost always a sign of a bad (as in loose/intermittent) ground or +12V feed. A 12V battery cannot deliver 18 volts and since two gauges show the same reading it's not a gauge problem. Don't get mad at me for suggesting that maybe you may not be reading the gauge correctly. But then if there is the number 18 on it and the needle points to it, you are obviously reading it correctly. Some have a "zero" adjustment but if the needle shows zero with key off, that's not the problem. All new gauges will not solve this problem. The speedo is not even electric except for the light. Other than the fluctuation issue, I can't believe the system has 18V in it with the key on/engine off. Did you have a battery charger on when you took the readings?

 

[parker1700]

Re: Grounding Problem

The volt meter reads from 8 to 18 volts and there is no zero adjustment on this gauge.. I used a multimeter an checked the voltage at the battery and at the back of the volt meter and both indicated 12.7 volts. It was not until recently that the other gauges either quit or started fluctuating I really feel like the problem is a ground that may be loose or corroded but wanted another opinion.

Fluctuating gauges are almost always a sign of a bad (as in loose/intermittent) ground or +12V feed. A 12V battery cannot deliver 18 volts and since two gauges show the same reading it's not a gauge problem. Don't get mad at me for suggesting that maybe you may not be reading the gauge correctly. But then if there is the number 18 on it and the needle points to it, you are obviously reading it correctly. Some have a "zero" adjustment but if the needle shows zero with key off, that's not the problem. All new gauges will not solve this problem. The speedo is not even electric except for the light. Other than the fluctuation issue, I can't believe the system has 18V in it with the key on/engine off. Did you have a battery charger on when you took the readings?

 

[Silvertip]

Re: Grounding Problem

Well -- you've proven you don't have 18V in a 12V system. That's a good thing. Check the voltmeter connections and make certain the ground terminal is actually connected to ground and not another circuit. It could be that the gauge has current for the dash passing through it so in reality it is functioning more like an amp meter. In other words its been wired (accidentally or ineptly) in series with the load rather than across the +12V and ground.

 

[DJ]

Re: Grounding Problem

Crossflow V-4's are NOTORIOUS for corroding the block ground.

The "block" ground is the negative battery termial lead attached to the engine block. Clean it-thoroughly, including bolt threads.

Been there-seen it..