Ignition Coil-gctid362049

[Guest]

OK electrical guru's...heres the deal.

My setup is in my signature, problem is that after unwrapping the boat and installing fully charged batteries, I turn the key on and voltmeter reads 9V. Hmm ok check the wires on the back of the gauge to verify gauge isnt faulty. 9V on the wires. Started looking for voltage drops, cleaning all connections as i go. Unplug Main engine harness, BINGO 12v on the gauge. Tore every wire off the engine, Alternator, starter etc. no go still 9V. Take leads of ignition coil, BINGO, 12V, but the coil is very hot. Not so hot that it would burn your hand, but still damn hot. My questions are should this coil be that hot and isnt a 3V voltage drop excessive ?

BTW all gauges had 9v to them, take iggy coil out and all have 12v now. Iggy coil is a NAPA coil and has part# 903 on it.

Should i just replace this thing and be done with it, cuz i dont think that is normal. Didnt really notice what it read last year KOEO but KOER the voltmeter read 12V.

Ideas ???

[Guest]

Points or electronic ignition? If the voltage went from 9v to 12v when you removed the lead from the coil to the cap, I'd investigate there (cap/rotor/points) first.

[captharv]

The coil draws about 4 amps, contacts closed. 4 amps and a 3V drop is a bout an ohm or so of resistance, somewhere, or a really sick battery.

The coil cannot draw enough current to drag down a good battery with good connections that far. You would need a couple of hundred amps to do that, and the wiring to the coil would burn up.

If it was my boat, I would try another battery, first then, use a digital voltmeter to track out the voltage loss.

See the laibray postb at the top of the technical discussion page, and read my posts about using a DVM to troubleshoot electrical problems.

[yachtman]

If the distributor stops at the spark firing point and the key is left on for a period of time it can get really hot. If its shorting out it can get really hot. Either way if it got that hot it's probably or already was bad or has been damaged.

[Guest]

Sorry...yes it is a points system and currently points are closed. Batteries are brand new last year, not being drawn down. Only thing reading 9v is the dash gauges...batteries are at 12.6

[Chief_Alen]

yachtman's gave you the reason. You can also weld the points closed if you leave the key on and the boat is not running and the points are closed.

Your setup uses a external resister ?

I think it did in 85'.

Rick would know for sure if it did.

You can't put straight 12v to the coil it has to have a resister.

[2850Bounty]

This may not be the problem..... but at the inside of your transom (Std side aft of engine) will be a white plastic engine harness/hull harness connector. It will be covered with a black fold-over boot affair. Peel this back, expose the connector, pull it apart and look at the female/male spade type fittings. Look for any signs of corrosion. Spray with a corrosion blocker... re-connect/pull apart/re-connect/pull apart... several times.

All of your engine data circuits and Ignition/Starter Motor etc, are in this harness.... including the helm Pos/Neg.

.

[Guest]

Rick, yea i tried that as i figured this would have something to do with feeding the helm. I disconnected the main harness cleaned with corrosion blocker and reconnected. Unplug and plug a few times to work the stuff in to it. When unplugged, dash read 12v but plug it back in an 9v. Am i going nutso here. I dont really know about points systems and what not, but if my system uses external resistor, is 9v KOEO normal at the helm? I know last year KOER the dash read 12v

[2850Bounty]

You may need to replace a few of these harness connector terminals (they are available).... or circumvent the OEM connector altogether, and use an alternate means of joining these two harnesses together.

[Guest]

Brad if you have 12v at the battery, 12v at the coil but 9v after the coil (your dash guage) and the coil is hot, I would say the resistance is at your coil and it may need to bee replaced.

[Guest]

I had a voltage drop problem on my prior boat, it had low voltage at the coil and wouldn't start. There was a bad connection in something and when I tried to start the boat the voltage to the coil would sign off. This of course was the morning of a fishing trip so we ended up fashioning a hotwire from the battery + to the coil and went fishing and after that the problem didn't come back. Not sure if I had something sticky in the ign switch or what happened there but it worked itself out.

If the coil is hot it's because the key ign is in "run" and the points are closed so you may have cooked the coil and welded the points shut.

Instead of the coil building and triggering a spark it's basically grounded out and the coils of wire inside become a heater. Even if it still works it can't be trusted and needs to go. Make sure you get a 3.0-4.0 OHM coil, these AQ 4-cyls use a coil with INTERNAL resistor unless someone has changed it.

[Guest]

rkcarguy wrote:
these AQ 4-cyls use a coil with INTERNAL resistor unless someone has changed it.

Where would one look to find said external resistor? The only one i can see is on the alternator on what im guessing is the sensing wire(ppl). nothing at the coil altho it does say "use with external resistor"

[Guest]

k-townguy wrote:
Where would one look to find said external resistor? The only one i can see is on the alternator on what im guessing is the sensing wire(ppl). nothing at the coil altho it does say "use with external resistor"

If there is an external resistor it would be a small white ceramic looking block and could be mounted anywhere if someone else installed it. I would think though that it would be the coil itself if you had no issues last year. As others have said you can fry the coil and or points by keeping the ignition in the on position instead of ACC to run items such as your radio/cd player.

[Guest]

well to be honest Dave i never paid attention to this issue last year. I know it read 12v KOER which leads me to believe this issue existed last year. Only used it 2 days before winterizing. BUT, how about this...Faulty ignition switch. B = B+, I = 10.5v. Now someone correct me if im wrong but there should be NO vD through a switch. Come to think of it, the PO mentioned something about the ignition switch not functioning correctly all the time. Did I just find the issue? I fired up the motor today with no issues and yes the voltmeter read 12v KOER.

[Guest]

k-townguy wrote:
well to be honest Dave i never paid attention to this issue last year. I know it read 12v KOER which leads me to believe this issue existed last year. Only used it 2 days before winterizing. BUT, how about this...Faulty ignition switch. B = B+, I = 10.5v. Now someone correct me if im wrong but there should be NO vD through a switch. Come to think of it, the PO mentioned something about the ignition switch not functioning correctly all the time. Did I just find the issue? I fired up the motor today with no issues and yes the voltmeter read 12v KOER.

Not quite sure I understand your question. Should there be voltage at the switch ? Yes dependant on the terminal you have the tester on. Should there be a drop through the switch not that you should notice. The bigger concern to me would be the warm or hot coil. If the ignition is off and things are wired correctly the coil should be cold. If the voltage going in is 12v the voltage coming out should be 12v but I have been know to be wrong before, ask my wife.