Tilt and Trim gauge

Rbsgfd578

Petty Officer 3rd Class
Joined
Aug 20, 2005
Messages
82
I hope this question is posted on the right board,but I have a 1984(thought it was an 85 but I was wrong) Johnson V-4 90hp, The tilt and trim unit work fine but the gauge doesnt.I was wondering if there is a way to troubleshoot the sending unit and the gauge to try and find out where the problem is?<br /> Also just wanting to make sure im right on this also since it is an 84 instead of a 85 is the plug that is called for a Champion L77JC4 gapped at 40?<br /> Thank you in advance. :confused:
 

dajohnson53

Lieutenant Commander
Joined
Apr 28, 2004
Messages
1,627
Re: Tilt and Trim gauge

You troubleshoot the sender by testing it's resistance at the full up and full down position. You need to know what the spec is for that particular unit, and need to have a multimeter and know how to use it. If you don't (know how to test resistance with a multi meter), let me know - it's easy.<br /><br />You test the gauge by seeing what it does with no power and full power. Whether it goes up at full power or down depends on the gauge (which is matched to the sender - some senders are high resistance full up, some are high resistance full down).<br /><br />If you go to the teleflex gauge site www.tflx.com, somewhere in the technical assistance section there is an excellent guide for troubleshooting all gauges including trim gauges and senders. They will have a spec for your engine's trim sender and what the gauge itself should do in the full power vs. no power test. The sender itself is OMC regardless of the brand of the gauge. The gauge therefore is matched to that type of sender, regardless of the brand of gauge, and therefore the troubleshooting for it will be the same regardless of the brand. <br /><br />The third link in this chain is the wiring from the sender to the gauge and the connections. That, in my experience, is the first place to look.<br />Good luck.
 

Rbsgfd578

Petty Officer 3rd Class
Joined
Aug 20, 2005
Messages
82
Re: Tilt and Trim gauge

By reading that link it says that Johnson at the gauge when it is gettin power away from the sender being connected that it will read full down.That is the reading I am getting right now without messing with it..What I am trying to ask I guess would that pretty much tell me that its either a bad connection with the sender or either the sending unit is bad or do you think I need to pull the gauge and run a new lead from the battery and check it that way?
 

willamettejeff

Chief Petty Officer
Joined
Nov 15, 2004
Messages
550
Re: Tilt and Trim gauge

If you ground the "S" terminal of your gauge it should indicate full up when turned on. If not the guage is bad. If always reading down, then could be bad sender wire up to gauge or bad sender. The sender is most often the problem particularly if boating in salt water. Whatever you do, do not connect 12vdc to the sender terminal or sender as you will damage the sender and/or the gauge. I highly suggest that, if you are going to be doing your own troubleshooting of problems, a good DVM (multimeter) is an absolutely essential tool. Of course, knowing how to us it is also essential.
 
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