The Stovebolt Site Forums The Shop Area Engine Shop My Coil is Smoking

I started my '55.2 with a stock 235 a couple weeks ago, fired right up. Tried to start it last week, wouldn't fire. Today I investigated. Pulled fuel line, hit the starter, spirting lots of fuel - all good there. Started checking power with a test light @ batteries, key switch, etc...; all good. Initially had power at both small terminals of coil, closed the points and had power at only one terminal' all good. Was looking around for other issues, when I smelled burnt electrical stuff. There's only one thing that smells like burnt electrical stuff, that's burnt electrical stuff! Coil was smoking! Always wanted a smoking hot truck! Turned the key off, pull negative lead from battery. Coil sits right over the ballast resistor. Pretty sure it was the coil smoking, but could have been the resistor. I'm going to replace both, as one can fry the other. Coil, resistor, cap, rotor etc... are all about two years old, installed by previous owner, probably Chineseium. Wiring, connections, etc... are fairly new and look good. Key was only on for maybe two minutes max.

Question: Besides replacing coil and ballast resistor, is there anything I'm missing?

Thanks,

Geoff

If the key was on and the points are closed, it would supply current to the coil overheating it and burning it out. I can attest to this as it happened to me while I was rewiring and testing circuits.

On another note, your coil and ballast resister should not be close together because they both generate heat. Most resisters are mounted on the firewall.

Replace the points while you're at it- - - - -they're probably smoked as well. NEVER leave the ignition on with the points closed!
Jerry

I’ll replace coil, resistor and points; and bench test the old stuff to try and figure what happened. Thanks!

A good reminder to me when I get to testing my wiring.

An ice pick type test light connected to a source of battery voltage can be used to test for wiring continuity without actually powering up a circuit. That way, the resistance of the light bulb in the tester prevents over current and blown fuses, etc. even under "dead short" conditions.
Jerry

While you’re at it, send a PM to fellow ‘Bolter Jon G and purchase one of his 200,000 hour condensers to replace the unreliable condensers that are now offered by all of the vendors. Many don’t work right out of the box and most fail shortly after.

Here is his contact info.

Yup, I have already done that.

Thanks

When replacing points, go to e-bay a look for NOS Delco points, they work much better than new ones.

I had found it’s super easy to leave the key on in my AD. No buzzer, stomp starter, etc.

One of my backburner ideas is re-wiring the ignition light so that it’s a reminder when it’s on.

It would be a simple matter to wire a buzzer or a warning light through an oil pressure light switch that would indicate an "ignition on- - - -engine off" condition. Once oil pressure builds up within a second or so of engine start, the warning system would shut off automatically, and stay off as long as there's oil pressure present. Most of those switches have a 7 PSI turn off pressure, so it would also serve as a "loss of oil pressure" warning.

www.ebay.com/itm/388768493582?

www.ebay.com/itm/255002901490?

Jerry

That's an advantage of never driving modern vehicles. None of my cars have warning buzzers for anything so I'm not psychologically dependent on cars telling me what to do about anything. I'm forced to make sure things are turned off, keys are in my pocket, doors are solidly closed, etc.

Despite my best efforts to be vigilant, I managed to lock myself out of my vehicle- - - -twice- - - -on the same extended road trip! Hiring locksmiths to get me back on the road made me opt for a door key attached behind a license plate in case I have another "senior moment"!
Jerry

I have done that. It's easy peasy.

That's a good idea.

I get my points from Steiner's New Parts for Old Tractors. They are all steel just like they used to be. One set has been on my 54 3100 for 3000 miles. Still look new. They fit "all Delco-Remy distributors with clip-on cap." Good quality. 5 and change +shipping.
Also have one of Jon G's condensers on.

Steiner's also has other bits and pieces for Delco-Remy distributors. I bought the terminal that passes the coil to points wire through the case of the distributor from them.

Ditto on Steiner's- - - - -lots of tractors in the 1940s and 1950s used Delco-Remy electrical systems: ignition, starter, and generator/regulator charging systems. Those parts are no different than the auto/truck equipment in most cases. Oliver 6 cylinder ignition parts in particular are virtual clones of stovebolt stuff. I even replaced the valves in an Oliver six cylinder head by swapping to 11/32" valve guides and substituting Chevy valves for the 3/8" stem Oliver parts which couldn't be found.
Jerry

Do you have to know what tractor cross references with automobiles or do you have to know the GM part number?

I bought a crapton of NOS Delco Remy points, for basically nothing, a few years ago on eBay.

If memory serves, I won the auction for like $1-2, and paid $7-8 in shipping.

Not saying that’s repeatable. But the NOS stuff is still out there.

No, but Steiner's is searchable by Delco-Remy part number. Try using the "search" box at THIS PAGE.

Here's a screen grab from the Steiner online catalog:

https://www.steinertractor.com/ABC018-Premium-Delco-Ignition-Tune-Up-Kit-with-Rotor

Be aware- - - - -the short rotor in this kit will not work with the "tall cap" Delco distributors used on the 12 volt stovebolt engines. Points and condenser should work OK.
Jerry

Don’t eat the points lube.

Oh man, that's the tastiest part!

isnt that sad though having to put warnings on DO NOT EAT?
Glass is sharp and ice is slippery. there seems to be a segment of society that needs instructions.

I think it is more of a defense against a segment of society that brings lawsuits when they themselves do something stupid.

Anywoo, that Steiner link is a good hookup. Didn’t ever think about them being a source.

FWIW, and I cannot speak from personal experience….I do hear mostly good things about the “Blue Streak” points sold by Standard.

I've been hooked on Standard Blue Streak since high school. I still order them when given a choice between any other brand (NOS Delco Remy excepted).

I haven't had any problems with them in any of my cars - all of them have points and they all get driven frequently. They seem to have escaped the Chinesification of their quality thus far.

Put a spare key in your wallet, I have spare keys to everything I drive or ride in my wallet zipper pocket. And it’s chained to my belt. I lost a wallet 65 miles out of Evanston Wyoming found out when I stopped for gas, from then on it’s been chained to me with spare keys. I found the wallet in the middle the highway where I lost it , begging for $12 bucks at a gas station so you can go find your wallet sucks as bad as getting locked out of your truck. Breaking a window on a newer truck to get into it it’s not bad but having to break a window on an antique truck now that sucks.

Never met an old GM I couldn't get into with a coat hanger. Of course, nowadays good luck finding a wire coat hanger!!

Update: OK, well after getting sidelined with the flu for a couple weeks and sidelined by Ford starting issues (bad starter) and sidelined by other life stuff for a couple weeks I finally got back to the '55 today.

A note: I didn't accidentally leave to key on, I had key on for a minute to diagnose the no spark issue; that's when coil started to smoke.

Thanks to all who chimed in; ordered Steiner points, rotor, and new coil, along with a condenser from Jon G (nice little unit by the way!). The only thing I definitively found was the outer contact on the rotor was badly pitted, contacts of the cap looked very good. The coil that was in the truck from the previous owner was a 3.0 OHM resistance, coupled with a ballast resistor, would that combination have burned the rotor to it's death? Could that combo fry the coil? Anyway today I replaced the coil with a new 1.5 OHM, a new 1.5 OHM ballast resistor, and new rotor - fired right up. Back in business!

I have to admit when it first wouldn't start I had to really think about the points ignition system, haven't worked on one in forty plus years. What is this, where does that go? I was a mechanic back in the '70's and worked on these things daily, amazing how you forget; but all came back to me in a few minutes.

Thanks,
Geoff

The pitted rotor tip is usually the result of using metallic-core ignition wires instead of resistance wires. The voltage from the coil jumps a small gap inside the distributor cap from the rotor to the individual plug wire terminals. Metal-core wires have virtually no resistance, so the spark acts like an arc welder. The rotor carries six times the number of spark impulses as the plug tower terminals, so it erodes more quickly.
Jerry

Very good to know. I'll check the plug wires in the next few days.

Thanks Jerry!

With the engine running, check the voltage at the coil + terminal to ground at the engine block or alternator housing. It should be around 9.5-10 volts with the proper combination of coil and resistor. With a fully charged battery and the engine running at a fast idle or above, the terminal voltage at the battery posts should be around 13.5-14 volts.
Jerry

I bought the Steiner ABC018 tuneup kit for my 53 216 engine with the original Delco distributor and found the points would not fit over the eccentric adjusting screw. The slotted hole on the points was too small. I ended up having to get points from NAPA which fit just fine.