Mercruiser 470 electrical

"On the base of the slave sole

"On the base of the slave solenoid is a yellow wire w/red stripe. Is there 12 vdc at that point w/the key off and the shifter in neutral?

Yes? Go to the key switch, put the shifter in forward and see if there is 12 vdc on the same wire at the key switch. Yes? Make sure the wires at the key switch are not touching. Disconnect the yellow wire w/red stripe from the key switch. Check the terminal to ground on the switch w/the wire removed for 12 vdc. Is 12 vdc there? Yes? Buy a new switch."

"Mike

contact me thru my e

"Mike

contact me thru my email.

click on my member name and it will have my email address.

I will give you my phone number and we can talk about this as it is not that complicated and there is something very simple you are overlooking.

Also get a test light for futher testing, NAPA ~ $12.00"

Thanks a bunch to all of you f

Thanks a bunch to all of you for your help with this. With the help from Kghost we were able to work this out and get this boat running again normally. Thanks again Kghost

So what turned out to be the p

So what turned out to be the problem?

Well it seems now it is back t

Well it seems now it is back to being a piece of crap again. It ran fine for a few minutes and now it is doing the same thing! Anyone think it could be the voltage regulator? When it sits for a few hours its fine until it runs for about 10 minutes. Kghost I will be calling you again soon.

"When I was helping im over th

"When I was helping im over the phone the coil had 3 wires going to the + side of the coil, one of those wires was the tachometer lead. He moved it to the - side where it belonged and he now had his tach working and the motor started and shut down. I heard it over the phone!

One thing that bothered me was he said that with ignition key in the off position and when the tach lead was on the + side, his test light showed power to the + side of the coil???????

That bothered me and when the wire was moved it went away???? Not sure about that but something is fishy with the wiring for sure......

I will follow up today with Mike today and find out more..........."

May want to encourage an inspe

May want to encourage an inspection of the starter solenoid...look for "disk residue" between the big battery lug and the "S" terminal.

"The solenoid is brand new as

"The solenoid is brand new as far as I know........

The +12 volts appeared to be active when the tach lead was on the + coil terminal. After he removed it he said the + 12 on the test light both to the + side of the coil and the tach lead was gone.

Dont quite understand yet whats going on or why that lead was moved from the - side of the coil????

There is 12 volts getting to the ignition on circut some where, Just need to find out where!!"

"Only thing I found in the thr

"Only thing I found in the thread was that the slave solenoid was replaced. Going by the pic, it was a 5082 (sierra), which the Merc Manual (#3) calls 'standard'. If he's got the presolite starter (No Solenoid), it's the wrong one if there's the "coil feed during cranking wire" connected at the slave.

If the Delco Starter (with Solenoid) is used, the solenoid on it has a pull-in coil and a hold-in coil. I've seen copper chunks from the disk come loose and make undesired connections inside the cover.

I'd pull the manual and verify what the harness was set up for (delco or prestolite) and then see if the correct "stuff" is there. Then figure if the wires are just in the wrong place or if 'corrections' are in order. If its a delco starter, I bet the 'shop' that checked it only verified that the coil pulled in and the starter spun....they omitted electrical verification of the rest of the solenoid's circuitry."

It is the starter with NO sole

It is the starter with NO solenoid on it. I asked him to verify over the phone.

He has the same solenoid as in the pic in prevous post. I ask and he verified and also it did work.

I went over almost every wire on the engine harness over the phone as I had the merc schematic in my hands and he verified each wire/color. There is still something missing but not bieng there to see/check myself makes it difficult.

What troubled me was the "tach" wire issue.

Someone has messed with the wiring. I tried to reach him yesterday but no answer or return call.

I think I would also suspect t

I think I would also suspect the solenoid as bieng bad. Maybe replace it as it is the ONLY thing I can see that could keep voltage to the ignition.

"You verified the wiring????

"You verified the wiring????

If you used the BIA color coded (later) diagram, did he verify the PUR-YEL between the ign coil and the slave solenoid? (this would be TAN on the earlier ones.)

If this wire is connected, remove it at the coil and tape it off. That '5082' solenoid is the wrong one - it will "work" but only for 1/2 of its assignment.

I hear you about the tach...probably the classic bird's nest behind the panel. I've seen many an instrument "malfunction" after being hooked up incorrectly so wouldn't give it a lot of importance. Replacement wouldn't be bad; I'd be inclined to disconnect it until the starter issue is resolved. then reconnect tach and condemn it or leave it & fill the fuel tank."

Just letting everyone know I a

Just letting everyone know I am taking the boat to the shop Monday morning. I will post as soon as I know something.

"Ive read all the posts and so

"Ive read all the posts and something bothers me. Getting back to his original post, "when he put the battery lead back on, the engine started" this surely means that when his engine is running, the starter is also going....still engaged to fly wheel?? causing major damage to starter? Am I missin sumtin here? This is like normal starting with key, but not releasing key, holding in start position whilst engine is running.. wow. major damage happenin.
Also, why did the engine stop when he pulled off the battery cable? wouldnt the alternator keep it going? or is the stator setup in the 470 different? normal alt setups will still supply power. (out of control unregulated power anyway)..mark"

"Well I wanted to post earlier

"Well I wanted to post earlier but had to work tonight so anyway I got the boat back from the shop. The shop checked all wiring and found nothing wrong, checked the starter and nothing there. The boat is runnning fine now since I got it back from the shop this afternoon. The shop told me they ran it over the course of 3 days and never saw the problem I described and it ran fine for them. They told me that everything looked great and the engine and wires are all in good shape. So why did this happen?????????? Makes no sense to me what so ever."

"OK.. heres a bold prediction

"OK.. heres a bold prediction from someone with big electrical experience..
Quote from Mike "Nothing on this boat is wired where it will run without the key" Mike has everything in his boat running via the Ignition Switch. Very bad design. The Mercruiser harness should only supply the engine and gauges. nothin else.
New mains wiring and distibution system from batteries should be installed for all extras.
Im betting accessories have overloaded his wiring harness a little, one two of the wires(the big red one & sumtin else) have got a little warm and melted together.. sometimes they touch, sometimes they dont.
Maybe the faulty tacho wiring played a part?
In my experience it is nearly always wiring causing problems, not components.
Mike needs to unplug the harness at each end and test between each core with an ohmmeter to see which ones are touching together. Could be controls harness or the engine harness. Un pluggin the big harness plug at the engine whilst running will isolate problem. Get a mate to move things around a little whilst testing.
neway its at the shop now, hope the're good at intermittent elec issues.
Hope mike gets back to us soon
sorry to those who thought this thread was dead..mark"

Just saw your new post! seems

Just saw your new post! seems whilst I was writing my post you were givin us an update.. well well.. nothin wrong. wow.
Do you have accessories in your boat powered from your mercruiser harness?

The only accessories I have is

The only accessories I have is a stereo and depth meter. Depth Meter is wired to key switch and the radio is wired hot. This is how it was wired when we bought the boat.

theres my overload theory out

theres my overload theory out the window. Still think there is a short betwen a couple of positive wires somewhere or sumtim dodgy in the starter.