'79 prestolite module test?

J

jeff campbell

Active member
:mad2:I have read most if not all the posts,maybe I missed it.but is there anyway to test the module/pickup in a p-dizzy out of the vehicle? It ran when I pulled the dizzy,a year ago,and I'm trying to help out a fellow binder.I just don't want to send it out and have it be faulty.tia very much.Jeff:confused:
 

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I don't know of any tests to the module itself, but you can test a mock-up on the bench with a battery (12v) at hand.

Get a coil, battery, plug wire with a spark plug, volt meter, small screwdriver, and mount your distributor in something stable like a vise with soft jaws.

Connect a ground from batt negative to the fixture/distributor (you're grounding the dist's body) and the spark plug's base. Connect spark plug to high tension tower of the coil

connect coil negative terminal to the module's brown lead, and the volt meter, the other voltmeter lead of course goes to ground.

Connect coil positive to the module's red lead. You will apply battery voltage here when ready to test, a switch is helpful but alligator clips will work too.

Position the rotor/trigger wheel so that the module is between Two(2) teeth.

Apply voltage to the coil + terminal. Ignition on

the voltmeter should read 5 to 8 volts. Go to a

if it reads 12 to 13 volts, check the distributor ground. If you're sure the ground is good, then the module is bad.

If it reads 0 to 5 volts, remove the brown wire. Keep the voltmeter hooked up. Reapply power, if it still reads 0 to 5 volts, the coil is bad. If when removing the brown wire the voltage goes to 12 to 13 volts, the module is bad.

(a)put a screwdriver blade between the trigger wheel and the module, the voltage should go to 12 to 13 volts.
Removing the screwdriver the volts should go back to 5 to 8.

If the voltage switches up and down with moving the screwdriver in and out of the gap, the module is okay. Then again if you can turn the wheel, you won't need a screwdriver provided the gap is set at spec.

Hope that helps, sorry no pictures:icon_mrgreen:
 
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Hi, I have Scout II and white wire in above photo isn't connected to anything. Engine idles good but with a little throttle it backfires profusely back thru entire exh system. Loud bangs. I suspect pickup coil - as that fixed a somewhat similar problem about 15 yrs. Ago. Voltage at brown wire in above test is a little low - about 3 1/2 volts. Battery voltage is present and varies 3 1/2 to 12+ inserting screwdriver in air gap. If it matters with this distributor, I believe at some time, key was left on.
 
Leaving the key on with engine off is generally bad juju regardless of ignition components. Damage usually ensues. The white wire just provides an ignition pulse to the deceleration control module, which is part of the emission control system. Most of those are non-functional by now and are generally discarded unless the vehicle is still subject to an under-hood visual inspection as part of the registration renewal process. They provide no benefit to engine performance or fuel economy.
 
I think I'll pass on the photoshop membership to look at your pic. Posting a pic in a thread is pretty simple. Couple ways to do it. One is to look for the paper clip icon, center right just above the text window. Click on that and it will open a "manage attachments" window. Then you can browse to the images on your hard drive. There are some size restrictions. Another way of accomplishing the same thing is to scroll the page down below the text window where you will see the heading, "additional options" and a subheading, "attach files". Six of one, same damn difference as t'other. If you want to get really froggy, you can preview your post, click on the image hyperlink, copy the url, and post that back inside the text window and the image will be imbedded full size within the body of your post. That's a little extra work though. Good luck with your repair. That is well above my pay grade in this case.
 
Sorry for reviving an old thread but thought my situation was applicable. I have a Scout II with 304 and prestolite electronic dizzy. I am getting gas but no spark out of the coil. When I check the ohms on the primary and secondary on the coil it all appears fine. However I was reading this post and I turned ignition to on with volt meter ground and put positive voltmeter lead on the negative side of coil and got around 7 volts but when I pull the brown wire off it shoots to 12.8ish. Does this mean my dizzy module is bad? Thanks in advance!!
 
Where would we be able to get a replacement module?

We appear to have a failed/failing distributor module in a prestolite distibutor in a 1979 Scout II. We want to replace or upgrade the item. Thanks
 
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I was able to get a replacement pertronix module for like 60 or 80 bucks. They are available all over the web, I think I May have gotten mine via xxxxxx. I will tell you that after replacing that, my Scout has never ran better. It has ran excellent off road and on since replacing the module. Hopefully this helps you!
 
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Perfect - I found it through an online search listed at 79 and at 109. Thank you so much. These forums are fantastic and have wonderful people involved. We are happy to have scouts and be a part.
 
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You talking the replacement factory 1 ? Best order it from xxxxx, ! ? not gonna get 1 no cheaper than that ! I'd hurry if I was you ! ?Jeff
 
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Gentlemen, that 1483a pertronix item is available for purchase from IHPA, the authorized light line vendor who owns and maintains this forum. Just so you know in advance of any future discussions, references to competing retail outlets or vendors is discouraged hereabouts. Thanks for your cooperation.
 
Hi scoutboy74.
The IHPA store does not list them. See below. A simple search function shows this item not found. That would have been easy if they were found in the store. The websearch for the same item, does not reference IHPA store from a google search, only to the forum, but does show links to many other parts houses, including ebay. Something that probably needs to be fixed - fyi.
Always happy to support fellow IH peeps, but admit the sites have to work right also. I edited my posts this morning, eliminating all references to competing retailer names in acquiring the item.
pertronix%201483a_zpsgmxrjsky.jpg
 
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Additional note - when I eliminated the manufacturer part number, and only search the word pertronix, IHPA does link to several items, but the actual specific part number referenced does not show up until you put the item in a basket to checkout. Just fyi to help you solve the lookup search function ability of the IHPA storefront.
 
For $137 bucks with shipping!?!? Hahaha. No thanks. I think I'll use the money I saved to get something else from them.
 
jgbrannan said:
additional note - when I eliminated the manufacturer part number, and only search the word pertronix, IHPA does link to several items, but the actual specific part number referenced does not show up until you put the item in a basket to checkout. Just fyi to help you solve the lookup search function ability of the IHPA storefront.
Click to expand...

I didn't find the part # either using the search feature.

knapp870 said:
for $137 bucks with shipping!?!? Hahaha. No thanks. I think I'll use the money I saved to get something else from them.
Click to expand...

Well you're also paying to support a small business in the IH community that doesn't have the volume of an amazon type store. That said I remember somebody saying that IHPA would try to price match.
 
I found it listed on the web store in less than 10 seconds. I didn't do a search by part number. What I did was navigate to it via the hyper links...something like this. Engine - tune up parts - pertronix. This brings you to a page where you have the option of choosing from a half dozen or more different distributor options. This is the normal process for placing online orders here. The accompanying product picture was by coincidence the 1483a. As for pricing, that's a different subject which I will refrain from opining on.
 
I just want to say thank you to everyone. This kit was installed over the weekend and my son says "tina has not run this well in a year" he is one happy camper. No more slow grinding starts, and no engine stops so far.
 
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