Ignitor HO-181 for Gold Box ignition I think it failed

[Rusty Scout]

No spark condition

I am still getting to the bottom of this but I do believe my ignitor ho-181 failed. I got this unit from summit back on 6/26 along with a flame thrower 40k coil #40111 1.5ohm and the pertronix universal 7mm black wires 708180.

Due to many other projects and the lack of a hood hinges for so long, my 1975 150 $350 buck truck project slowed to a crawl. So I estimate that the pertronix stuff I got in there has a total run time of under 4 hours. 3 days ago I went for a drive for the first time in a long time. It had idling problems so I cranked the idle up to 1000 rpm. 2 blocks later the engine stalled with no signs of life. I had to tow it back home with my 79 Scout 345 prestolite/ignitor/flamethrower/7mm wires that have always worked so well.

Voltage at the coil + is only 10.5 volts and during cranking it drops to 10 volts.

 

[Michael Mayben]

First, remove the switched b+ feed to the coil positive terminal completely.

With no load on the electrical system, measure open circuit battery voltage directly at the battery terminals, a fully charged battery will show an approximate 12.6>12.8vdc open circuit (no load).

Measure switched b+ between the removed terminal and ground using a voltmeter. Measure first with the ignition switch in the "on" position, then with the switch in the "start" position. Since your wiring harness/truck was an oem setup with the prestolite electronic distributor, there should be no "resistor" wire in the ignition "run" feed, even though there could well be a resistor wire buried and deadheaded inside the loom and is not used on this application.

So you are looking for no less than 11.0vdc when cranking on that wire. Any less...the p-tron module can't function, it goes into a shutdown mode.

If b+ feed voltage is "low", then ya gotta battery/charging system issue going on and the p-tron can't operate. So don't home in on a faulty p-tron until the battery and charging system is verified as operational.

Typical charging voltage of the 10si alternator during the first five+ minutes of operation after the engine starter load is applied will be 14.2>14.6vdc...and then taper back after say ten minutes at idle to a nominal 13.4>13.8vdc...every alternator/battery combo will vary somewhat so those numbers are ballpark for any 10si.

 

[Rusty Scout]

Thanks mm for looking. Just to clarify the no spark condition is on my 1975 IH 150 that came with the original gold box system, 2210c and 304. I am going to run those tests today and will get back with some results asap. But here are some wiring diagrams for the 1975 150 Travelall. If I had to guess I bet wire 16-16 has something to do with it.

And

 

[Rusty Scout]

Mm in case you are wondering how a wheelchair user gets under the hood on a 150

The next set of crime scene photos are not for the faint of heart

 

[Rusty Scout]

Well I have a new battery that May be slightly run down at 12.62 volts at the posts.

I got serious and started attacking some sick wiring and pulled all the gold box and decel stuff.

I pulled the engine bulkhead and found dirty connections, twisty turny crap and 3m scotch tap in connectors. I scraped some of the crud off the female firewall bulkhead connections and got 12.60 volts at the +coil wire firewall connection. The males are going to need some work. Previously I was only getting about 10v at + coil with the pertronix(gold box and decel out of the loop) and 7v with the gold box/decel in place at + coil when I reverted back yesterday.

At least this tells me that the ign switch on the column can provide nearly full voltage in the run position. I have not gotten to test the start position yet but I will soon.

 

[Scoutboy74]

You sir, are an inspiration!

 

[Eric VanBuren]

No need to mess around trying to clean up those terminals in the bhc. They are standard "packard 56 series" terminals and are available at napa. Larger stores will have them hanging on the spinner rack with the pigtails and light sockets. Smaller stores will have to order them up, you'll need to have them look them up for a 70's GM though.

There is a special tool to remove the terminals from the connector but you can do it with a small screwdriver and/or paper clip depending on if you are working on the male or female terminal.

 

[Michael Mayben]

well I have a new battery that May be slightly run down at 12.62 volts at the posts.

I got serious and started attacking some sick wiring and pulled all the gold box and decel stuff.

I pulled the engine bulkhead and found dirty connections, twisty turny crap and 3m scotch tap in connectors. I scraped some of the crud off the female firewall bulkhead connections and got 12.60 volts at the +coil wire firewall connection. The males are going to need some work. Previously I was only getting about 10v at + coil with the pertronix(gold box and decel out of the loop) and 7v with the gold box/decel in place at + coil when I reverted back yesterday.

At least this tells me that the ign switch on the column can provide nearly full voltage in the run position. I have not gotten to test the start position yet but I will soon.

Thanks for the pics steve!!! Now I understand what ya described to me! That access apparatus is also something I need to get my lardazz back in the engine bay and access the typical shitball wiring! I'm on this deal but I'll make sure you get credit for the inspiration!

I blew out my cell last Wednesday, the replacement has just now been placed in service and I retrieved the voicemails that ya left. But I think we're on the same page now, sorry I didn't respond to ya.

In my work, I eliminate the oem bulkhead connectors when at all possible/practical. Those are the number one service issue always with any IH light line vehicle. They were shit quality when new, under ampacity when spec'd by ihc, and are a constant source of gremlins. In today's automotive service climate, they would have been a basis for a massive recall.

When ya git time steve, post up some picks of your hand control systems. If scoutboy 74 keeps roomin' with sailor jerry, he's gonna need a set also in his sii.

 

[Rusty Scout]

Yeah I am leaning towards chop, remove connector from system and solder/shrinkwrap.

Is there enough slack in the wires to do this or do I need to compensate for that? Also, any recommendations on type of grommet to use in place of the bulkhead connector?

Micheal, do you have any pics of some of your bulkhead rewiring handywork?

Also I double checked the ho-181 and found no shrinkage on the overheat indicator sticker.

 

[Michael Mayben]

I use plain old barrier/terminal strips to replace the bulkhead connectors. There is normally enough slack in the harnesses (inside the cab and in the engine bay) to allow this.

For a grommet, I just snake stuff from the local parts house which are found in the aftermarket assortments.

For some reason, I have no pics of a typical repair! That's not like me at all as I try and document everything.

Here's a source for a really nice protected terminal strip that I'm considering using in the future:

stud type junction box

This is the typical terminal strip/block I normally use, the jumper can be "cut-to-fit" to allow custom configuration of switched or un-switched loads. Similar items found at radio shack are certainly adequate also:

65 ampere terminal blocks - blue sea systems

 

[Rusty Scout]

Pertronix got back to me when I inquired about a warranty on the ho-181 and they replied with a test procedure to verify if the ignitor is working properly. I thought I would share:

before we warranty the ignitor we need you to do the following tests to
determine that the ignitor is bad and your system is working properly.

Please see attachments for test procedures.

Your vehicle May have the factory resistance wire in the wiring harness
which can cause the ignitor to be erratic and cause surging, backfire, poor
idle and other similar symptoms. Pay close attention when doing the voltage
test and make sure voltage is approx. 11.5 volts with the (-) coil terminal
grounded.

 

[Rusty Scout]

Pertronix also sent this document on power and grounds:

Do not disconnect wires from ignition coil and place ignition switch in the off position.
Use jumper wire (with alligator clips on both ends)
connect jumper wire from negative (-) side of coil to a good engine ground.
Connect volt meter red lead to positive (+) side of coil and black lead to engine ground.
Turn “on” the ignition switch and note voltage reading. Quickly read voltage and turn ignition “off”. Leaving ignition switch “on” could result in permanent damage.
See chart above for specifications.

Note: low voltage can be caused by poor connections, poor contacts in the ignition switch, ballast resistor, and or a resistance wire in the wiring harness (factory installed).

 

[Michael Mayben]

Thanks for sharing that doc steve! Good info!

The "primary resistance/ground" test holds true for any distributor/trigger system!!

Nothing will kill the primary side of a point-trigger inductive ignition system any quicker than "high resistance" across that circuit. Point resistance is a factor always addressed in oldskool tune-up. And...new breaker points right out of the box must be cleaned (with contact cleaner) across the contacts and then tested for excessive resistance. During the manufacturing process, a non-visible protective coating is normally applied to the tungsten contact to protect against oxidation while sitting on the shelf.

Oldskool tune-up instruments have a special "low ohms" scale used for checking primary resistance...that makes a big difference in overall ignition performance. Same holds true for all these electronic trigger conversions and/or electronic trigger distributors.

Same for the braided bonding/ground cable that connects the movable breaker plate to the stationary plate, ya gotta have a bonded ground between 'em of some sort, ya can't depend upon the vacuum canister to furnish a ground.

Here's a shot of one of my peerless engine analyzer components. See the control knob marked "point res"? When this instrument is connected to the ignition primary circuit and the proper test sequence is selected, the point resistance is read directly as "low, normal, or high". Just cleaning the point contacts and the ground path can reduce the point resistance from "high" to "low" which is what we're after. Makes a huge difference in ignition coil output/performance. Many coils are replaced needlessly simply because of poor grounds in the primary side of the system.

This "ground/resistance" deal is why I will never simply stick an electronic trigger conversion in any distributor without first tearing it down completely for cleaning/rebuilding. There is nothing more scruued up than a distributor that has been in service for 30+ years with no luv!

This is a great thread for troubleshooting/diagnosing this kinda juju!

 

[Rusty Scout]

I don't mean to be defiant but since I have more time than money I will try to clean the bulkehead.

So I spent the day cleaning the bulkhead connector and reinstalling the pertronix ignitor back into the Holley gold box distributor. Each of the connectors inside the bulkhead were cleaned. All 16 components were made bright, shiny and tight. I am getting battery voltage at the bulkhead but I am only getting 11.35 volts at the + side of the coil(about 1.3 volts better than before). That old stiff coil + wire is losing 1.3v somehow.

Also I am not seeing a bonding wire on the breaker plate. According to my Scout manual the Holley distributor 1530 the sensor plate is retained by 2 long screws. Cts 2665q page 15 #6 says to separate the two plates you must remove a 3 pronged retainer spring from the bottom of the lower plate (fig 19). #7 says separate upper and lower plates and remove 3 thrust buttons from the upper plate (fig20). I am assuming that the plates are bonded with a combination of the retainer spring and the thrust buttons.


Back to the drawing board. I will start by replacing the +feed for the coil and running the ignitor tests. All I have is a cheap digital vom to do this with. Thanks

 

[Rusty Scout]

The pertronix resistance test was performed on the distributor. No changes have been made here. The hold down has not been disturbed for at least 2 months.

The meter test leads by them selves were 0.2 ohms. The resistance reading from the ho-181 ignitor aluminum mount to the battery negative terminal fluctuated from 0.3-0.4 ohms.

By subtracting the resistance of the leads we are left with 0.1-0.2ohms which is in spec.

 

[Rusty Scout]

I took the Holley dizzy off and tested the hall effect of the ignitor. All was well. I tested the new flame thrower coil with an ohm meter and it seemed fine. Just for the heck of it we hooked up the original coil. Big spark!!!!! It runs killer now. It was the chinese flame thrower coil with the 90 day warranty. Out of warranty now cheap pos. So much for the pertronix epoxy flame thrower 40kv. Poor thing has been running on half a spark all this time. Runs killer now.

While I had the dizzy out I took the plates out and made them immaculate. End play is .035 right in spec. Vac advance is tight too.