470 won't start - electrical short somewhere?

Hey all - I inhertited my dad's old 1978 Ranger 1850 Fish & Ski. It's been out of the water for the past few years and I'm trying to get it water worthy again. I've found lots of good info here already, but am stumped on an issue so I thought I'd make a post.

The engine will turn over, starter rolls the engine, but no spark. The last time it was started was probably 2 summers ago. Back then it had brand new plugs, wires, distributor cap, points, etc. Basically the Sierra tune-up kit. It started up pretty good but several of the gauges were flaky (batt, temp, fuel). I'm pretty sure the tach didn't work at the time either.

Now fast forward to this spring - tried starting it up and it won't start. The shift-kill switch checks out ok. I've also replaced the coil while trouble shooting - no change. Using a multi-meter from the +side of the coil to the possitive side of the battery and with the ignition OFF I get 12.5 volts - as expected. Turn the key to the RUN position and that voltage drops to 0.3 volts. Everything I've read says it should be at least 7.5 or 8 volts in that position. It has a resistor wire, but most issues with them or corroded connections drop it a little lower to say 5 volts. But I'm thinking i've got a short to ground somewhere since it's going to ~0.3 volts. The wiring back at the engine is pretty straight forward and nothing looks in too bad of shape. So then I started looking at a ground in the intrument panel because of the gauges acting up.

Next thought is that it might be a shorted tach. I've disconnected each of the three wires that go to it (+, tach, grnd) one at a time and it makes no difference. I also tried disconnecting the +bat wire that leads to the fuse block - thinking that that might cut one side of several of the gauges but I didn't see any change in voltage at the coil when the key was in RUN.

Any experience with a similar no-spark issue? Am I on the right track that it's a short? Any idea of the most common culprit or a way to rule things in or out?

Sorry for writing a book - but I've spent a lot of time on it already and wanted to give you details.

Thanks,

Re: 470 won't start - electrical short somewhere?

Any experience with a similar no-spark issue? Am I on the right track that it's a short? Any idea of the most common culprit or a way to rule things in or out?

Click to expand...

Ayuh,.... Welcome Aboard,.... Change the Points....

Re: 470 won't start - electrical short somewhere?

I agree with him^^^ new points in her

The coil will be getting power to that (+) terminal on it while the key is turned to the "run" position thru the resistor wire and will deliver your 6-8volts. Tested with DMM lead on (+) on coil and a good ground on the engine.

While the engine is cranking (starter is working), the coil receives power thru the purp/yellow wire off the starter solenoid and gets full 12v to start the engine. Tested the same: (+) side of coil and the other DMM lead to a good ground.
The resistance wire helps prolong the life of the points.

You can remove the grey wire off the (-) side of the coil which is the sender wire to the tach, if it or the tach is messed up will kill your spark.... to check.

Re: 470 won't start - electrical short somewhere?

Points were brand new and set 2 years ago by a boat mechanic. Shortly after that I had it run on a hose in the driveway for maybe 5 - 10 minutes, but since then it hasn't been started. Think the points would have degraded while stored in a barn?

I've pulled the coil wire where it connects to the center of the distributor and watched it while cranking, it gives NO spark at all to a good ground at 1/4" or less. That's why I was suspect of the coil, because it was getting voltage with the key in the OFF postion. But when turned to RUN, it gets almost nothing. I don't recall the voltage value while cranking - may not have tested that yet.

Can try pulling the grey wire from the Neg side of the coil to disconnect the tach that way. I tried the wires at the gauge itself.

Thanks for the suggestions. Keep them coming...

Re: 470 won't start - electrical short somewhere?

RammaR said:

Points were brand new and set 2 years ago by a boat mechanic. Shortly after that I had it run on a hose in the driveway for maybe 5 - 10 minutes, but since then it hasn't been started. Think the points would have degraded while stored in a barn?

I've pulled the coil wire where it connects to the center of the distributor and watched it while cranking, it gives NO spark at all to a good ground at 1/4" or less. That's why I was suspect of the coil, because it was getting voltage with the key in the OFF postion. But when turned to RUN, it gets almost nothing. I don't recall the voltage value while cranking - may not have tested that yet.

Can try pulling the grey wire from the Neg side of the coil to disconnect the tach that way. I tried the wires at the gauge itself.

Thanks for the suggestions. Keep them coming...

Click to expand...

Points are something that's replaced on a yearly basis as part of your annual tune up.

If you go to the Adults Only sticky at the beginning of this forum there is TONS/HOURS of good info which is were these are from:

Read this please it will help you out big time:

How To: Troubleshoot a Points Ignition System
http://forums.iboats.com/showthread.php?t=335407


How To: Tune-up Your Engine with Points Ignition
http://forums.iboats.com/showthread.php?t=335302

Here is your tune up kit for the distributor: $28.99
http://www.iboats.com/mall/partfind...gd_poid=355783&gd_row=16&session_id=748000502

Re: 470 won't start - electrical short somewhere?

Don & Eric +1.. You need brand new points this year! They go bad just sitting.

Re: 470 won't start - electrical short somewhere?

Hadn't seen that guide yet - thank you. Under "***Troubleshooting 12 volt (+) coil supply***"

there is no voltage or significantly less than 4 volts (+), there is a voltage issue at the coil. -- that sounds exactly like my issue right now.

I haven't done the jumper wire test, but the wires leading to it look to be in pretty good shape. Will try the jumper wire though. If that doesn't do it.. then I'll check out the harness as it details.

The points aren't that much $$$, so will look at them too - but I really think the problem is upstream since the coil isn't getting sufficent power.

Re: 470 won't start - electrical short somewhere?

Followed the steps yesterday up to this point:

If there is no voltage or significantly less than 4 volts (+), there is a voltage issue at the coil. -- reading was 0.36v -- Extremely Low

- Connect a jumper wire to a known good 12 v (+) source, and the other end to the coil (+) post. Connected the jumper wire direct from the +pos battery terminal to the +pos side of the coil

- Turn the engine over.

- If you have good spark (thick, blue spark) at the spark tester, you now know you have an issue with the (+) voltage supply to the coil. No change - no observable spark from the tower wire of the coil.

I didn't disconnect the other two wires from the +pos side of the coil (resistor wire & normal power supply) when attaching the jumper. Should I have? I didn't want to burn the points by giving it the full voltage, but then started thinking that since they were left attached, wouldn't the short still be part of the circuit?

The How-To guide is a little confusing from there - it looks like the next steps detail how to troubleshoot the issue if I had gotten a good spark with the jumper wire. I'm not as clear on where to go since I didn't get any spark at all - unless again it was because the other wires were still attached.

Thanks again.

Re: 470 won't start - electrical short somewhere?

Im no expert but have some experince with a similar issue as of late, Disconnect everything from the coil except the wire leading to the Distrubutor, and your jumper. Your not going to burn up the points that quickly. If still no spark after trying that....replace the point.
If you do get spark then start re-connecting one wire at a time to the coil until the problem is there agian..... You found your bad connection there then.

Best of luck!

Re: 470 won't start - electrical short somewhere?

Have you changed the points and condenser yet?

One other note, when you check voltages, you do it with the black test lead to ground (battery negative terminal), not the battery positive terminal.

Re: 470 won't start - electrical short somewhere?

Don S said:

One other note, when you check voltages, you do it with the black test lead to ground (battery negative terminal), not the battery positive terminal.

Click to expand...

I've started with the Seloc manual before writting here. Based on it's troubleshooting I thought I'd ruled out the condenser - but you bring up an interesting point on checking the voltages.

To check for a spark, the manual suggests disconnecting the wire that runs between tower on the coil to the center of the distrubtor (i can't recall the name of the wire, but it looks like a plug wire) - at the distrubtor end. Then holding it 1/4" or less from a good ground and checking for a spark when cranking the engine. I took some sandpaper and cleaned up a spot on the block / bolting to ensure it was a solid ground (verified with DMM). I'll run out to the auto parts store tonight or soon and pick-up an actual in-line spark tester. I sorta liked the idea of testing for a spark while knowing the boat wasn't going to start - so I didn't have to run water to the drive unit. It's been so dry here that the city has put restrictions on water usage.

But for voltage testing - where I was reading 12.5v with Ign OFF, and then 0.36 with it in RUN - was red probe at the +pos terminal on the battery and the black on the +pos terminal of the coil. If it was reversed, I'd get -12.5 volts. I could have sworn the Seloc manual said to test that way, but maybe I misinterpreted it. Because if it has battery voltage there, then there is no differential to measure and it should be essentially 0v - close to what I've got.

Maybe I've been testing it the wrong way all along - doh. That would make me feel pretty stupid. I'll check that out first thing when I get home and try to report back!

Haven't got the new points / condenser in yet. I've been more focused (possibly falsely) on an upstream issue. I still think there is a short to ground somewhere because of the gauges not working properly. But it used to at least start up and run so I knew which ones were having issues.

Thanks.

Re: 470 won't start - electrical short somewhere?

RammaR said:

I've started with the Seloc manual before writting here. Based on it's troubleshooting I thought I'd ruled out the condenser - but you bring up an interesting point on checking the voltages.

To check for a spark, the manual suggests disconnecting the wire that runs between tower on the coil to the center of the distrubtor (i can't recall the name of the wire, but it looks like a plug wire) - at the distrubtor end. Then holding it 1/4" or less from a good ground and checking for a spark when cranking the engine. I took some sandpaper and cleaned up a spot on the block / bolting to ensure it was a solid ground (verified with DMM). I'll run out to the auto parts store tonight or soon and pick-up an actual in-line spark tester. I sorta liked the idea of testing for a spark while knowing the boat wasn't going to start - so I didn't have to run water to the drive unit. It's been so dry here that the city has put restrictions on water usage.

But for voltage testing - where I was reading 12.5v with Ign OFF, and then 0.36 with it in RUN - was red probe at the +pos terminal on the battery and the black on the +pos terminal of the coil. If it was reversed, I'd get -12.5 volts. I could have sworn the Seloc manual said to test that way, but maybe I misinterpreted it. Because if it has battery voltage there, then there is no differential to measure and it should be essentially 0v - close to what I've got.
Maybe I've been testing it the wrong way all along - doh. That would make me feel pretty stupid. I'll check that out first thing when I get home and try to report back!

Haven't got the new points / condenser in yet. I've been more focused (possibly falsely) on an upstream issue. I still think there is a short to ground somewhere because of the gauges not working properly. But it used to at least start up and run so I knew which ones were having issues.

Thanks.

Click to expand...

To test for power at the coil:
key switch to run, red test lead on the (+) terminal of the coil, and black test lead to a good ground on the engine or (-) of the battery, don't put the black test lead to the (-) terminal of the coil.

Re: 470 won't start - electrical short somewhere?

Haven't got the new points / condenser in yet.

Click to expand...

Then you are wasting your time with all the measuring and posting. Put points and condenser in it, set them correctly, and you will have spark.

Get up away from the computer, put some points in, and come back and tell us how it works.

Re: 470 won't start - electrical short somewhere?

Don S said:

Then you are wasting your time with all the measuring and posting. Put points and condenser in it, set them correctly, and you will have spark.

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Message loud and clear and I truely appreciate the help. This may be a dumb question, but can you help me understand why if I don't get any spark directly from the coil itself, which is upstream of the condenser and points, how will changing them will make it better? If I got a spark, any spark at all, from the coil but then no spark or too weak of one from the distrubtor then I'd have already rushed out and gotten those as suggested.

I'm an engineer, but not an electrical guy - so maybe i'm just looking at it all wrong. But would like to understand so I don't have to ask again later.

Thanks.

Re: 470 won't start - electrical short somewhere?

OK you asked for it LOL. The coil is simply a step up transformer. The primary has few windings, the secondary many. So when your points close, current flows through the primary to ground (12V), setting up a strong magnetic field. When the points open the current stops and the magnetic field collapses and this collapsing magnetic field generates a large (20,000V or more) voltage in the primary which is fed to the center of the distributor cap to the rotor and jumps the gap to the proper terminal and out the plug wire to the spark plug. In order for it to work properly the points must make good contact and be closed long enough (dwell) to generate the optimal magnetic field in the primary. There you go coil 101.

Re: 470 won't start - electrical short somewhere?

Thanks for the education on the step-up transformer - thathelps a bit. So replacing points sounds like an annual project. I don't have a dwell meter or the feeler gauge, but those could be bought.

Here's the question though - by the time I snag all that or take it to a mechanic that could do it - I'd probaby have spent almost as much as one of these conversion kits:

http://www.iboats.com/mall/partfind...&gd_poid=355901&gd_row=8&session_id=086350450
or
http://www.iboats.com/mall/partfind...&gd_poid=111673&gd_row=8&session_id=086350450

What are the negatives with upgrading from the points / condenser system? Any special tools or tricks needed to install it?

Thanks.

Re: 470 won't start - electrical short somewhere?

I personally like the Petronix conversion kit, Ignitor II module pn. 91146A along with the Flamethrower II coil pn 45111 (epoxy), 45011 (oil). The Petronix looks like it is about the same as the Sierra but I am not sure. http://www.pertronix.com/

Re: 470 won't start - electrical short somewhere?

I'm not sure where you are buying tools but Amazon has everything you need for about $52.00 (plus shipping of course.)
Points - $6.00 (yes, you need them)
Feeler guages - $4.00 - you need these anyway to set the plug gap.
Dwell/Tach - $25.00 - you'll need the tach whether you switch to electronic ignition or not.
Timing light - $17.00 - again, you'll need this for either ignition system.

That's less than 1/2 the cost of the electronic ignition system and the tools will serve you well for years to come.

Re: 470 won't start - electrical short somewhere?

Been on the road for most of the past week, but got to mess with the boat again today -- and I wanted to come back and say THANK YOU. Although I didn't want to beleive it, the issue was the points after all. A little light filing and bam, it started right up. Now that I know that was the culprit for sure - I'm gonna grab the Pertronix setup. Found the 1146a kit for $63.95, then I don't have to worry about adjusting them again.

Again, thanks for all the advice and patience.

Re: 470 won't start - electrical short somewhere?

Dont know if this can help,

I had starting issues on my 4 cylinder 488 mercruiser
At times would start at the turn of key. Then for some reason when turning key dead, silent
At times getting spark other times no spark
No cranking of starter, dead silent.
Batterys good
When I jump starter,off starter senolid it cranks and starts up.
Tracing electrical is a slow process and slower when doing it yourself
I had a number of issues
Biggest issue was grounding and electrical harness.
Ground off of engine too neg of battery had corrision and ends of cable were coming out of terminal ends that bolt too engine
But the biggest issue was a ground wire that came off the bolt of the starter slave senolid. On my boat working on engine is not
an easy process and senolid is not clearly visable, Once I found the loose black wire, hooked back up too one of the bolts supporting the selenoid it cranks and starts right up.
I still beleive there is an occassional issue in electricial harness as when I turn key still has a dead spot but on second turn cranks away.

Once in the while dead spot is either starter seneloid , or some were in electrical harness. I am not stranded, while out there, I can
jump or call sea tow if it continues, but fixing something when its working is a process
Good luck