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2004 Mercury 115 ELPT4S **Trim Gremlins**

R

RyanHoman

New member
Good Morning.

I have a 2004 Mercury 115 ELPTS four stroke with a Mercury binnacle top mount control box with trim switch (88688a26).

My issue is at my trim switch at the control box. When I try it I get nothing, when I try the switch on my motor, works like it should. I thought it might be the switch or connections at the switch. Replaced the switch, nothing. Used my meter to test voltage at red wire 12.4 when touching the other lead to either the green or blue wire. I’ve tested continuity from the switch connections to the male plug under the console, same with female plug to female bullet connectors coming from inside engine at harness. If I unplug my main harness inside engine I lose voltage at switch, plug back in and again have voltage at switch, but no operation even if I jump red to either blue or green.

I have not done anything with the relays yet due to them working properly with the switch on motor. Is there a connection at the relay for the remote switch? I’m really puzzled and of course I’m heading to the keys in 5 days...

I want to add I just replaced my steering and shift cables, pulling on wiring I’m sure... Also replaced my trim pump which works flawlessly on the switch at the motor. The switch at the control box did work prior to me zip tying everything from the motor wiring grommet to the side entry grommet on boat.

I appreciate any help and your time on this matter.

Thank you,

~Ryan
 
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Since you have a multimeter check voltage into and out of the switch and then follow it back to the pump. I don't mean check the wire in the middle of the run just at both ends unless you see a need to. Since it is most likely that a wire is loose (this may be only poor connection not really hanging loose) check both the wire and the connector it is attached to separately.
 
Fixed!!

First let me say understanding troubleshooting of electrical systems is still new to me...

Friend of mine recommended using a test light.

Got back to the house, immediately tested what I thought was 12.6 at my red wire and nothing with the test light..He had mentioned about think of electricity like water flow, start at the source and go from there. So I started back at the engine harness and found 12v heading out the engine. I found the next connection under the console, and that’s where I found a bad positive connection. The female 3 prong plug for trim up/down/power where spliced into the harness about 18” down. From what I can tell it was done like this from factory. I also noticed the blue and green wire were also in bad shape, so new heat shrinked splices with added wire was how I repaired it.

Im still confused and why I would have a voltage reading with my meter when I touched my red to red and black to either blue or green.

Either way glad it’s fixed.

Thank you for your time.

~Ryan
 
The drawback to using a volt meter is that while it will tell you that there is voltage present it can't tell you how much (quanty not voltage which is electrical pressure). If you ground to anything that is grounded somewhere down the line the volt meter will tell you that there's juice available. That is why it is so important to ground to something that goes straight to the battery unless you are wanting secondary system readings.
 
Having a bad connection can show voltage when no current is flowing. When current flows (the bulb) the bad connection's Resistance, times the current I, drops enough of the Voltage such that the light doesn't have enough current to illuminate. It could still have some voltage across it however. V=IR...V in volts, I in amperes (in this case milliamperes...thousandths of an amp) and R in ohms. Volts is a measure of electrical potential difference between 2 points. Ampere is a measure of electron flow in coulombs (needs another definition....number of electrons passing a point) per second. Ohm (1 each) defined as a voltage drop of one volt with 1 ampere flowing through it.

This realization of yours is interesting as I for one seldom test a circuit for "load" (current flowing) voltage. Good point to remember on circuit problems that don't make sense.....as yours. Thank goodness I haven't had any of those for quite awhile.

Edit: Just remembered, I do battery capacity testing like that, but that's about all.
 
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That's why I like the water hose illustration for most electrical explanations; voltage is pressure, amperage is quantity of flow and resistance is restriction of flow,watts is how much work did the flow accomplish.
 
Texasmark, I was an auto tech for 40 some years and few things bothered me more than "it can't do that" situations and quite often low supply voltage or a poor connection was to blame. Can make you want to pull your hair out.
 
Swagonmaster said:
That's why I like the water hose illustration for most electrical explanations; voltage is pressure, amperage is quantity of flow and resistance is restriction of flow,watts is how much work did the flow accomplish.
Click to expand...
That's the quick way I explain it to non-techies and it works.
 
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