smoking ballast resistor?

P

Plug Ugly

Member
Per Maybens wiring, im trying to get this 61 going. I tunred it over, and was getting no spark from the coil primary wire to ground, so I got a new coil. Now, hooked up, the ballast resistor has started smoking as soon as the battery is hooked up.

Any thought? Did I fubar something up in the wiring? The wiring is per the write up for ignition and start leads.
 
By the way, this is key off. Just with the battery hooked up. The damn resistor gets hot just sitting there. Is it ground ing out somewhere? I replaced the I wire from key switch to ballast lower mount, no change

and this new coil does say its for an external resistor (been reading the hot coil thread)

kragen part numbers
resistor duralast dr794
coil borg warner e30

and it didnt start smoking till I changed coils
 
Last edited:
Disconnect that battery now!!!

Ya gotta dead short to ground in the primary circuit if the sukker is drawing current like that with the ignition switch off! So ya got two separate issues here, one is current draw with switch off (that's a dead short), the other issue is a coil/resistor mismatch for the 4 popper system.

Rather than scruu with that, simply run a new ignition primary circuit.

And...the coil "spec" is different for an I-4 engine setup as compared to the specs for the sv engine!!! I'm gonna make this simple and describe wire runs.

The "hot ticket" (no pun intended) re-wire is as follows:

1) no "resistor wire" feed to the coil at all! Eliminate that wire from the entire harness but do not toss it, save for some other project if it's still good. Coil it up and put it away!

2) you need a ballast resistor of 0.8ohms nominal. I keep wells p/n al795 around here for this purpose. Tell the counter monkee that ya wanna resistor for a 1963>1971 dodge/plymouth/chrysler points ignition system, take your ohmmeter and check the sob on the counter! Again, that is 0.8ohms, not the same as the 1.8ohms unit we use for the sv points system! Big difference!

3) ya needa coil with a primary resistance of a nominal 3.0ohms. Again...that is different from the coils we use for the sv motors! They do not interchange (electrically speaking).

4) run a minimum 14 gauge wire from the ignition switch "on" terminal to one side of the resistor, I mount the resistor right on the coil bracket in some manner where it's convenient. Then run a pigtail from the "out" side of the resistor to the coil positive (+) terminal.

5) connect your new distributor pigtail to the negative(-) side of the coil.

6) run a minimum 14 gauge wire from the starter solenoid/relay "r" terminal. That will provide full b+ to the ignition coil when the starter cranks the motor over. When ya release the switch to the "run" position, then current is applied to the ballast resistor which then feeds the coil at less than b+.

The wire runs I describe are exactly the same as I've outlined in the homebrew wiring spreadsheet I sent ya. Except, that system includes the additional "remote" starter solenoid mounted on the firewall, in that system the new relay provides the b+ feed to the coil in the "start" position.

Now...if you set the dwell to 74* for the delco distributor, the current draw through the primary side of the ignition system will be a nominal 3.1>3.4 amps, which is perfect for the 4popper motor and the points will live a long, happy life and the coil will exhibit perfect saturation!
 
So, im a ohm idiot. How do I check resistance for a resistor and coil.
Welding and fab work I can do, electrical stuff, not so much
 
Piece of cake! Just set your volt meter to ohms (looks like an upside down u) touch your meter leads together meter should zero out. Disconnect the wires to the ballast resistor and place one lead on the input and one lead on the output side, you May have to adjust the scale on your meter, depends on the meter, and it will read the resistance. For your coil do the same across the + and - terminals. Thats it.
Ron
 
Ya really need to use a dvom (digital volt/ohmmeter) to check resistance values that low with any accuracy!

Ron's procedure is correct!
 
michael mayben said:
The wire runs I describe are exactly the same as I've outlined in the homebrew wiring spreadsheet I sent ya. Except, that system includes the additional "remote" starter solenoid mounted on the firewall, in that system the new relay provides the b+ feed to the coil in the "start" position.
Quote]


Just spent a few minutes and fully digested this. . I drew out the wire runs from your excell spreadsheet (im a picture guy, not a word guy) and followed it precisely .

wire #9 . ign switch to bottom of resistor (in)
#10 ballast out to coil positive .
11 . remote starter relay ign to coil positive
12 . coil negative to points


that is how I had it run .

also, have any part numbers for the coil ? I tried finding any specs on the e30 coil from bwd automtive that I had gotten through kragen, but can not find anything . autozone does carry the wells (or duralst version) of the al795 however .


edited for this reason:
after re-re-re-reading this and looking at what I have drawn down, I think I have it wired exactly as you indicated both here and in your write up.
Click to expand...
 
Last edited:
Found this from you on another forum

m. Mayben said:
for the record...one more time.

Any inductive ignition coil with a primary resistance of between 1.5ohms and 1.8ohms primary resistance will operate correctly and allow correct coil saturation/primary current whether fired off breaker points or a pertronix. The resistive value will change as the coil heats in operation, this ain't rocket science.

With the pertonix, you can use either the ballasted feed to coil positive or a b+ feed, do whatever ya want! Makes no difference in starting/performance! Ya wanna see scope patterns that prove this?

Can't find a wells, try the following, they are all the same value and will be priced all over the planet!

Standard motor parts uc12
niehoff dr178
napa eichlin ic 12 (prolly the most expensive chinamex coil on tha market, another reason I won't pay napaprices!)
borg warner e30
gp sorenson gc300

or try any coil spec'd for a dam 60's>70's GM whatever with points distributor.

I'll not pay more than $14 for any of these coils, and that was as recent as two weeks ago for the standard.
Click to expand...

So I guess my coil is 1.5 to 1.8ohms huh.
 
Ok plug...I see the confusion!

In my spreadsheet, an additional starter solenoid/relay is added to the existing solenoid mounted on the starter itself. Around the IH world, that's known as adding a "Ford solenoid" as a convenient point for accessing the "start" side of the system and connection point for the main fuse panel feed.

Both ignitions feeds to the coil go to the positive terminal of the coil only! One is the start feed (b+), the other is the run feed from the ignition switch.

The only wire that is connected to the coil negative terminal is the pigtail from the distributor points. Later, if ya add an electric tachometer, those are normally triggered from the negative coil terminal also.

If you have either of your ignition "feed" wires connected to the negative coil terminal...then that is a dead short to ground!

A common 3 ohm coil is a "generic p/n 504. That will be the number stenciled on the coil itself, the "packaging" part number May either incorporate that number...or be an entirely different number.

One callout you could use is a coil for a Chevy II of the mid/late '60's, those used a near identical distributor/dwell as the IH version of the same sparkmaker. Also, any 6 cylinder chev of that era (235/250) would use a 3 ohm coil.

We just bumped haids!

That wells spreadsheet is a great resource, somewhere I have about a 150 page spec book produced by mercotronic for their coil testers that had every coil spec for any coil ever manufactures, whether a magneto coil, an inductive/battery coil, a cd coil, whatever. Wish I could find that!

I repeat!!! The coil you want for the 4 banger is a 3.0ohm unit!!! Three ohm primary! Sound like you have now found the correct ballast resistor. Do not use the same coil as used on the IH v8 apps!, that would be like the wells #819. Those are a nominal 1.4>1.8ohms measured with a typical dvom.
 
Last edited:
Gotcha. I had it wired correctly then, as I am using a Ford starter relay (mounted up underneath the fender bolts on the pass side inner fender. Ill post some pics when I get some time) so I am assuming, that there is a short somewhere. Is it possible the key switch is bad?

Thanks for the link to the coils, I will see what I can come up with.

Autozone shows the c819 for the 68 Chevy II, nothings ever easy.
 
Yeah, and all the lookups show a standard motor parts uc 12 or uc12t which is the equivalent of the wells c819. So I don't know why all the lookups are wrong!

Also, I'm looking for specs on a delco e552c as a possible 3 ohm coil.

Update!!

Look for a gp sorensen p/n gc 124 or equivalent. I found another new one in my parts stash and verified the primary resistance with my dvom is 3.1ohms at 62*f. Gp sorensen is an old time brand name now parked under the "four seasons" holding company which also includes standard motor parts:

"the standard division markets engine management parts under the standard, blue streak, hygrade, gp/sorensen, federal, filko and cobra brands. The four seasons division markets temperature control parts under the four seasons, everco, murray, air parts, and factory air brands."

Another update!

Looks like the cross reference to a standard motor products coil p/n is uc15x. The cheepo "trutech" version would be: uc15t. That coil is appropriate for thousands of euro 4popper applications back into post wwii as long as they were 12vdc apps (not 6vdc). Also for all chev 6poppers if 12vdc oem.

Sorry for the delay...we lost all communications up here again today, no landline/dsl, no I-net, cell was ok. We're back up right now.
 
Last edited:
Just got off the phone with the niehoff tech line. He looked up a few coils for me. Their number, should anyone want it is 1-800-566-8334

standard motor prodcuts
uc-12 is a 1.3 to 1.5 ohm unit for use with external resistor
uc-15 is 3.25 to 3.5 ohm but internal resistor

borg warner is e500hp (also e30) which is 1.3 to 1.5 external
e502 is 3.25 to 3.5 internal.

While im not arguing with you micheal, this guy was convinced that the 1.3 to 1.5 coil is thr correct one.



Edit
just called them back
a delco e552c is external 1.3 to 1.5 and crosses with bwde504
the gc124 crosses with the uc-15 as above, or a e81 from standard, whcih is now an e40 which is 3.25 to 3.5 internal
 
Last edited:
Ok, looks like we have correct verified info posted now.

I don't wanna "argue" with the niehoff dude either...but those folks read from a screen! And no doubt...his "screen" tells him the "specs" for that coil. And, he's correct! But he is regurgitating "company line" based upon parts consolidation! I mean...even pertronix "tech" gets it right in that respect! And they are real smalltime players with the coils outsourced through messkiko and china.

And an "internal resistor" coil is not the same thing as a "use with external resistor" coil !!!! The primary circuit wiring for those two totally different items is not the same!!!

But...has he ever actually measured "correct primary current flow" inna four cylinder, point-triggered, inductive ignition system??? Hell no, there ain't nobody even produced any engine with that setup in the last 25 or so years! In other words there is hardly any market for a coil of that spec except for the folks that play with 6popper chev and Ford and chrysler restos (or hillman minx, humbers, or a mg magnette)! And us (all 20 of us in the u.s.!!).

I'm tellin' ya, the "lower" resistance coil is perfect for a points v8 app...no discussion there!!! But not for an IH 4popper with either a delco or Holley distributor! And we've not even mentioned that some of those engines were equipped with the gawdawful lucas distributor! See all my previous posts regarding sv (not I-4) ignition guapo!

"doing the math" on this kinda stuff means nothing other than a starting point (maybe)! The "math" is all dependent upon a perfect set of conductors, terminations, constant/fixed voltage/current supply, and lab-condition temperature control of components! I used to do this kinda product technical support crap for living (12 years)! And that is what service manuals are written around since they "specs" are pulled from "math" and engineering data...not real world!

But the only thing that matters is the real world, when the motor is running at an underhood temp of 235*f, with a battery output that varies with engine speed (generator/alternator rpm) with "average" condition wiring/wire terminations.

This ignition stuff is not a "one size fitz all" kinda deal like the aftermarket parts manufacturers like to make an end-user "think" that is the case because they no longer supply all the variations of components that there is no longer a market for! So they look at "similar" stuff and make consolidations with nothing optimized for individual systems except chryfordrolet! And there is even less of a market for breaker point ignition systems/components!

And this situation constantly changes! Right now, there are many parts in my dbase that were plentiful from multiple suppliers just 2/3 years ago...no problem finding on the shelf anyway, not "special orfer" stuff. Now those numbers are nla in one fell swoop since the primary manufacturer of the part in question no longer produces. That means all the re-pak/private label "brand names" disappear also unless residual inventory is sitting in some wholesale distributor "dead stock" dark warehouse corner!

That is why we're always looking for new sources for this stuff and this only comes up when someone discovers the "nla" excuse! Just you posting this thread, has stimulated me (and others I'm sure) to see what alternatives are out there! Otherwise, I'd would have never scruud with this until someone else brings it up...or I need a coil for my shop/use and go to town and find out I'm sol! Then it's back to the office to do the research and try something else!

But a modern day, retail auto repair/parts operation can't spend the time and money doing what I and others around here do for a hobby! They just advise the customer to "trade it in"! Customers won't pay for hours of research on the I-net trying to find a part. Exactly what most shops won't even talk to ya about fixin' an IH product, they'll just say "can't get parts, take it to the scrap yard while steel prices are high"!

We're a bit different around here...the ihon business depends upon finding the right stuff for the customer, many times it's not quick and ez, many times it's real pricey, but that is what this business is based upon! That's called a market niche!
 
Last edited:
Wouldnt you know it, all these coils are 51 bucks.

Seems id be ahead by going with a pertronix (at least cost to performance), and keeping the 1.3 ohm coil for 27 bucks.

Unitpoint and above coils (20 and 50 dollars respectively) for 70
p-nix and cheaper coil (85 and 25) 40 more bucks (plus or minus) and you get a seemingly better ignition system.
 
A pertronix 1141 (basic unit) requires the same 3.0 ohm coil as a points-trigger system! Current is current!

There is no pertronix II unit for a delco 4 cylinder distributor, though it "May" be possible to modify the trigger wheel supplied with a 91181 to support the module...but if you try and fail, it's irreversible, and very tedious and exacting to attempt. According to pertronix, that item "can" be used with an ultra-low resistance coil, but I will not do that (based upon personal experience) unless I'm using the p-tron to trigger an msd or mallory "6 series" cd box. Big difference!

A coil with a primary resistance of under 3.0 ohms has no use in an IH four cylinder ignition system using points or the pertronix!

The crane xri module is much more advanced and simple than the pertronix since it's a "lobe sensor" item. Will it work on a delco 4 cylinder distributor point cam? I haven't tried it and will not say even "maybe"! Technically it will work, but until I install one I won't say yes or no. I intend to do so soon however for comparative purposes in both an sv delco and an I-4 delco. The version to use would be the "chevrolet" model, not the one for bop distributors.
 
To support this topic, I'm posting some additional info based upon real world proper matching of ballasted primary circuit ignition feed, a freshly built delco distributor with a dwell factor of 74* (breaker points not pertronix), and an ignition coil of 3.1ohms primary resistance value (verified again). And the "warm engine" operational voltage in this case is 13.8vdc at idle (550rpm).

This shot shows a primary current "draw" across the entire system (breaker points) of 1.9dca. That is perfect ignition coil saturation factor which is a balance between performance under full load/max rpm for a 152/195 engine, and long breaker point life!

In actuality, the current varies constantly between 1.7adc and 2.2adc because the total circuit resistance on the primary side is constantly changing due to alternator output, and changing resistance across the points. That is why an electronic trigger system is far superior to any breaker point system once it is correctly set up.

The maximum current draw across the points I'd ever want to see is an upper limit of 2.5adc>2.9adc.

Again, these numbers are for a conventional inductive ignition system using breaker pints for a trigger.
 

Attachments

  • Primary current at idle.jpg
    Primary current at idle.jpg
    105.4 KB · Views: 1,313
Here's a tight shot of the 3.1 ohm coil including part number under the gp sorensen brand.
 

Attachments

  • 3 ohm coil for I-4.jpg
    3 ohm coil for I-4.jpg
    102.9 KB · Views: 1,891
This is a long shot of a 4 banger ignition system which is my own. And it's heavily cleaned up from the oem IH crapwiring sitch!

You are looking at a delco distributor with points (perfect condition with oem advance curve), an aftermarket (this one is from msd) 0.8ohm ballast resistor, no "ballast wire" is used, the ballast resistor takes it's place, and the 3.0 ohm coil.

The jumper you see attached to the pigtail is for a ballast resistor "bypass" when using other distributors incorporating an electronic trigger (such as a pertronix 1181). Same thing is done when I install a distributor using a crane xr3000 optical trigger conversion which is a "high energy primary" inductive ignition system which eliminates the breaker points similar to a pertronix.

This 196 motor is not long for the world. It'll get yanked next month for a total buildup. Plan is to use a flying magnet crank trigger ignition system on the motor with a gutted distributor and locked out advance. Timing control will be provided by a msd 8979 ignition controller in tandem with a msd 6 box. The distributor will be gutted and only used to distribute energy to each plug in turn, no advance unit, no trigger internally. We're looking for a solid 195+ flywheel horsepower out the completed motor for street and trail use. On regular grade fuel running a carb (no efi in my world).
 

Attachments

  • Long shot I-4 Delco system.jpg
    Long shot I-4 Delco system.jpg
    116.2 KB · Views: 1,212
Last edited:
plug ugly said:
just got off the phone with the niehoff tech line. He looked up a few coils for me. Their number, should anyone want it is 1-800-566-8334

standard motor prodcuts
uc-12 is a 1.3 to 1.5 ohm unit for use with external resistor
uc-15 is 3.25 to 3.5 ohm but internal resistor

borg warner is e500hp (also e30) which is 1.3 to 1.5 external
e502 is 3.25 to 3.5 internal.

While im not arguing with you micheal, this guy was convinced that the 1.3 to 1.5 coil is thr correct one.



Edit
just called them back
a delco e552c is external 1.3 to 1.5 and crosses with bwde504
the gc124 crosses with the uc-15 as above, or a e81 from standard, whcih is now an e40 which is 3.25 to 3.5 internal
Click to expand...

You can use the ~3.0 ohm coil that is listed as internally resisted.

A coil that is marked "use w/external resistor" is marked as such because it will overheat and fail if used w/o it. There is no reason you can't use an external resistor with a coil that is "internally resisted".

Coils that are marked for use with external resistor will overheat and fail if used w/o ballast resistor because they are not capable of handling the amperage that will result if not used with a current limiting device (ballast resistor).

If you check out the coil section of the pertronix catalog you will see that they got it right their coils are listed as "internally resisted" even the 1.5 ohm units, meaning they won't overheat if used w/o a ballast resistor.

40,000 volt coils
while it’s the perfect coil to go with the pertronix ignitor breakerless
ignition, our 40,000 volt flame-thrower canister coil can benefit virtually
any distributor type inductive system. Its higher voltage allows larger spark
plug gaps for added power, smoother response and better fuel economy.
These coils are internally resisted so they are compatible with many
ignition systems.
Click to expand...

Which just means that they can be used w/o a ballast resistor in applications that don't have it or with a ballast resistor in applications that do.

http://www.pertronix.com/catalogs/pdf/ptx/2007/ptx07_coil.pdf
 
You must log in or register to reply here.
Back
Top