Starter won't turn with trim cables connected...

[franko989]

Hi, hoping someone would have an idea of where to start troubleshooting this problem.
1999 SCR 2400 (I have the manual in picture-form if anyone needs it...) with a Mercruiser 5 litre / Alpha 1 out-drive
When I have the cables from the trim motor connected to battery, starter will not turn. Take them off and away she goes. Really like to have my Alpha trim feature back, any ideas where to start looking?
(You may have guessed I'm not very technical...)
Appreciate any feedback.

[pascavone]

you have a short in the trim motor or trim switch.

leave the cables on the battery and unplug the control wires to the trim switch and see if it starts.

[mmwjr]

franko, not sure what cables you are refering to so hard to understand the problem. There is no trim interlock to the engine started. As Pas said it's some type of short. Here is a wiring diagram. If you can provide some better discription better advise where to look will follow.



BTY: Blue is up (blue sky) and green is down (green ground)

[mmwjr]

BTY: I use an older diagram that has the trim buttoms on the helm instead of the one showing the switch built into the shifter because this shows where each wire is connected to the buttons and the other doesn't

[ss3964spd]

Originally Posted by franko989

When I have the cables from the trim motor connected to battery, starter will not turn. Take them off and away she goes.

Frank,

Since we can't see your particular set up from here, three clarifications needed;
1) When the trim/tilt positive and negative cables (which are smaller diameter than the main positive and negative cables) are connected to the battery, AND the main positive and negative cables are also connected, are you saying the starter will not turn AT ALL? No slow turning, no clicking, nothing at all from the starter?
2) Does trim/tilt work normally when both sets of cables (trim/tilt and the big positive and negative cables) are connected but you are not trying to start the engine?
3) Is there a battery switch being used?

I am no wiring guru but I'm having a hard time seeing this as a short circuit caused by the trim/tilt motor or solenoids. If that were the case I'd think those smaller gauge wires would be melting when you try to start the engine.

Dan

[mmwjr]

Dan, for not being a guru you are dead on that a short would melt those wire like a fuse. Agree questions 1 - 3 need to be answered. If trim pump were shorted the solenoid isolates it until trim switch is activated. If solenoid were shorted to ground fuse would blow.

Really lost on this one.

[franko989]

Originally Posted by ss3964spd

Frank,

1) When the trim/tilt positive and negative cables (which are smaller diameter than the main positive and negative cables) are connected to the battery, AND the main positive and negative cables are also connected, are you saying the starter will not turn AT ALL? No slow turning, no clicking, nothing at all from the starter?
2) Does trim/tilt work normally when both sets of cables (trim/tilt and the big positive and negative cables) are connected but you are not trying to start the engine?
3) Is there a battery switch being used?

Dan

First off...Wow, thanks for the replies gentlemen. mmwjr that diagram will really help so thanks again!
In answer to Dan's queries, I would say Yes for number one. Nothing going on at all.
For number two, also yes. I noticed it occurring this spring during clean-up and launch. Engine wouldn't start so thought my battery AND booster pack were pooched. Charged both and this time the engine went. Actually it was dead at first but kicked right off when I messed with the throttle stick a bit. I definitely lowered the drive to start the engine with the muffs on and left it down for launch as I thought it was killing my battery.
3, yep there is a switch in place, the (I assume) factory Guest Charge Pro. Only running one battery off of it and followed the manual to make sure I jumpered things correctly.

Cheers for the help!!

[mmwjr]

Ok with all wires connected (not sure they are connected properly yet at this time) trim pump works and O/D goes up and down.

With wires (which ever ones you are removing) the engine starts. Are you saying turn of engine hook up wires and try to start all in ~10 minutes and the starter does nothing? Or is there a long period in between and batteries are drained and must be recharged to start? Something connected wrong draining the battery.

Do you turn the battery switch to off when not using the boat? This should isolate the battery from most things other than bildge pump and maybe radio memory.

Also you mentioned "charged both" is this 2 batteries or one battery and the booster pack? wasn't clear.

Are you removing the thick (battery) black or red wire? If so then no power to engine.

Can you take a few pictures showing when connected and when not?

[CountryME]

Frank,
Lets start with some basics. The diagram from Mike is great, but doesn't show how the starting/charging system and your trim system tie together. How many big red wires and how many big black wires are we dealing with here? Do you have separate positive (red) cables feeding the starter and trim motor, or are they in series (i.e. red cable runs from battery to starter, then from starter to trim motor? Same goes for the ground. Do you have separate ground (black) cables running from the battery to the engine and trim motor, or do they run in series from the battery to the ground stud on the back of the motor then to the trim motor? An understanding of how the power is getting from the battery to the two devices of concern can clear up the troubleshooting steps. Simple pictures help some of us with simple minds too. So if you can sketch out a quick diagram of what you actually have, it may help us give you some more advice.

-JP

[ss3964spd]

Hmmmm......

So we know that the tilt/trim works correctly when its +/- cables are connected - which means there are no shorts there. We know the starter will crank the engine, and the engine will then start, when the main +/- cables are connected but the T/T cables are disconnected, so the cranking and ignition circuts are fine.

When the T/T system is not being used, but is connected, it is not drawing any power from the battery. If it were you would hear something; either the T/T motor would be running or the solenoids would be cycling (clicking). Further, I don't see any way that the T/T connections could possibly render the cranking circut completely inoperable.

I believe we're missing a piece of the puzzel. You mentioned above:

"Engine wouldn't start so thought my battery AND booster pack were pooched. Charged both and this time the engine went. Actually it was dead at first but kicked right off when I messed with the throttle stick a bit."

In the above scenario were both the engine and T/T cables connected?

You also mentioned the battery switch, and that you're only using one battery. Is only one battery physically installed? If there are two, is anything at all connected to the other? If there's only one, are the various cables connected directly to the battery or are they connected to the switch, or are some cables connected to the switch and others to the battery?

If I were wearing your flip flops I would:

Disconnect all cables/wires from the battery and/or the switch
Connect only the T/T +/- cables, no others, to the correct posts on the battery.
Verify T/T operation.
Remove T/T cables.
Locate and connect the main +/- cables to the correct posts on the battery.
Verify the engine will crank, but do not allow it to actually start.
Reconnect T/T +/- cables to battery.
Verify T/T operation
Verify engine will crank.

At this point I'm inclined to believe you've got a wiring issue. That, or the starter circuit lock out is what is tripping you up ("but kicked right off when I messed with the throttle stick a bit") and it's only a coincidence that it is happening when you are trying to get the whole mess to work.

Dan

[pascavone]

well, trim and trailer up switch is always on.

even when the battery switch is off.

so, sounds like the only problem is the engine start which would lead me to the main battery switch, as the starter is probably wire one lead on each of each of the batteries terminals on the dial, and the "always hot" trim pump negativity is trying to complete the circuit.

unless someone actually wire the trim upto the battery switch which is incorrect and your trying to start your boat on a 16 gauge wire.... (this would mean BBQ!)

[mmwjr]

Just to clarify the trim and trailer switch have power (not on) to them and will be activated when the switch is pressed.

Since no smoke was mentioned I don't think there is an undersized wire. I suspect improper connections are being made.

[franko989]

Great input, thanks everyone. I will be going to the club today so planning to get some photos and create a wiring dgm to help troubleshoot.