Mercury 50hp throttle control sticking

[Poly]

Well, according to this (Wiring Color Codes for Mercury & Mariner Outboard Motors.) the green and blue (with white line) are the trim up/down switch. the brown might be for the trim guage I'm not sure if it has a white line on it in the picture - if it is connected to anything at the engine end it will provide a signal which you can test on a multimeter (12V dc). Alternatively it is tan not brown in which case it is probably an "overheat alarm" (i'm guessing an older 50hp doesn't have an actual temperature sensor which outputs a range). Is the other wire red ? If so it is probably 12V live all the time.

Now the fact that your PTT is working fine and these are not connected might mean these are "spare" e.g were the wiring that was supplied with the control but it has been wired directly to the switch etc. In which case these might well all do nothing!

[Downhilldai]

Merc control boxes have 'spare' cables for various gauges: oil pressure, water temp, etc.

[9D280]

How many multicores you got coming out the throttle box?

If the second loom is PT related it's either going to be for a second station or as Pol says, you have 2 variations of age between engine & controls - I think the older ones had a separate PT loom, because it was an expensive optional extra so the loom came with the PT. Your engine looks a bit newer than the controls, so you may find that pevious owner has spliced the new "everything" cable form the engine into the remotes, and not bothered to remove the old "extra" PT cable?

Mine has a spare Grey for the optional temp switch for what it's worth.

If they all go back to the engine, you have lots of free wires for gauges! If not, I see a weight saving opportunity!


Oh, and for checking the "send" to the tacho, any needle meter with an "AC volts" will work - It will give slightly random, but constant readings. (Send" is basically connected to the alternator coils, and the tacho counts the pulses).

[Ruari 29]

Biggest problem I have now is the engine keeps blowing 20amp fuses, im sure its not a loose wire as it runs fine I stop and start then I stop the engine then boom. I have changed battery terminals already. Been told quite common with mercurys

[Jeff]

Originally Posted by Ruari 29

Biggest problem I have now is the engine keeps blowing 20amp fuses, im sure its not a loose wire as it runs fine I stop and start then I stop the engine then boom. I have changed battery terminals already. Been told quite common with mercurys

Have you checked the routing of the trim switch wiring into the handle. They could bechafing and shorting as you move in / out of gear and/or operate the trim ? ...... I have the tee shirt
Jeff

[Ruari 29]

Jeff that sounds like the cause, will strip down the controller at the weekend

[9D280]

While you are in there, can check out the connections and / or remove the random tail you found under the seat.

[Ruari 29]

Spaghetti junction, I hate wiring, im thinking about buying a brand new controller and loom. Seen one on ebay for £180 same style and boxed?

[9D280]

Originally Posted by Ruari 29

I hate wiring

In that case my suggestion of moving the spaghetti to the console will not be top of your favourites list then!

Fair enough. Just make sure the electrics are compatible with your engine. As I'm using a modified Yam one on my Merc, I can't actually say for sure how standard the Merc electrical connectors were through the ages. I'm sure someone like Uncle Al or TD will be along to comment soon.