Ignition woes. My mechanic sez................

[72bumbee]

My mechanic is pretty secure in the fact that voltage spikes are frying the Mallory unilite point replacement in my distributor...cont afford another one, so on his advice, I’m considering going back to the factory installed distribution.
How easy will this be?
Also, does anyone know where I can get the three wire bunch that comes through the firewall and feeds the coil and hooks to the oil and temp. sending units...? It’s a three prong hookup at the firewall.

[72bumbee]

One other think about the Mallory unilite point replacement distributor. On the metal end of the rotor it looks burnt. Would that be indicative of anything significant? Concerning the ground strap located below the Mallory add in, does it need to be over or under where the screw holds the Mallory in place or is there a preference?

[sargentrs]

My mechanic is pretty secure in the fact that voltage spikes are frying the Mallory unilite point replacement in my distributor...cont afford another one, so on his advice, I’m considering going back to the factory installed distribution.
How easy will this be?
Also, does anyone know where I can get the three wire bunch that comes through the firewall and feeds the coil and hooks to the oil and temp. sending units...? It’s a three prong hookup at the firewall.

Is this the harness you're looking for? https://www.summitracing.com/parts/SDK-C9ZZ14289BB/

[72bumbee]

yes i do believe that is it! I also remembered that rob roy directed me to a similar item a long time ago.....
I think there needs to be a few modifications to the connectors, but will serve the purpose.
Thank you my friend!
any tips about the distributor swap?

[Ranchero50]

Points dizzy is dead simple. Buy a spare condenser when you get it and keep it in the glove box for when your off shore sourced one fries.

[72bumbee]

I really think I need to check out the Mallory Unilite to make sure it’s toast. I think I saw a tutorial online about how to do it.can you tell me what exactly I’d be testing for?
I have a multimeter and could probably figure it out if I knew what I was looking for.
Just hate to throw away $113.00 on that Mallory unit and not know for sure that it’s toast.

[1972hiboy]

I think the real question here is voltage spikes? From the truck, is killing your mallory ignition? If that's the case you need to look at that problem before replacing the ignition components again.

[72bumbee]

Thanks for the pointers... as I have another thread going on this subject in the engine board, I’ll sort of abbreviate.
The truck sits out in the Oregon rain 12 months a year. Is it possible that the moisture is causing the havoc? I’ve replaced light switches and ignition switches just this year and now wonder why this little Mallory Unilite just this year decided to take a crap? It has run for this long with the Mallory, what gives this year?
What should be my next step?
I’ve replace voltage regulator
Solenoid
Battery
Dizzy cap
Mallory Unilite ( I put the ground wire under the screw that holds it in... not under the unit.)
New alternator is on the way.
Thanks again everyone!

[Thipdar]

Thanks for the pointers... as I have another thread going on this subject in the engine board, I’ll sort of abbreviate.
The truck sits out in the Oregon rain 12 months a year. Is it possible that the moisture is causing the havoc? I’ve replaced light switches and ignition switches just this year and now wonder why this little Mallory Unilite just this year decided to take a crap? It has run for this long with the Mallory, what gives this year?
What should be my next step?
I’ve replace voltage regulator
Solenoid
Battery
Dizzy cap
Mallory Unilite ( I put the ground wire under the screw that holds it in... not under the unit.)
New alternator is on the way.
Thanks again everyone!

Since the ongoing voltage is produced at the alternator, it's the most-likely culprit for causing the voltage spikes.
I'd have replaced the diode block in the alternator, then checked to see if the spikes were gone.
If they were still present, I'd swap in a new/known good Voltage Regulator.
Replacing the entire alternator may be a little bit of 'overkill', but my guess is that's what should fix the problem.
If the spikes ruined the Mallory unit, it should get replaced as well.

[72bumbee]

Thank you Thipdar!
The truck ran the longest (10 minutes) after replacing the voltage regulator.
I just picked up the new alternator...could the alternator be killing the regulator?

[72bumbee]

is there any chance the Mallory unilite may be salvageable?

[Thipdar]

Thank you Thipdar!
The truck ran the longest (10 minutes) after replacing the voltage regulator.
I just picked up the new alternator...could the alternator be killing the regulator?

I believe that might be possible, especially if the VR is solid-state (the OEM VRs were mechanical).
If you have to replace the VR again, try to find a mechanical unit - they're more expensive, but also more robust in the face of danger (such as unwanted voltage spikes).

[Thipdar]

is there any chance the Mallory unilite may be salvageable?

I've got no experience with them and can't give you an honest answer.
Try to eliminate the voltage spikes... once you do that, check the Mallory unit again to see if you need to replace it.
Changing out the Mallory unit before eliminating the voltage spikes might kill the replacement Mallory.

Also, a word of caution here:
Keep your battery charged up while you're doing all of this; if the battery gets way-low, you could toast your new alternator once the engine starts running right, just because it's suddenly trying to meet an unexpectedly heavy load.

[72bumbee]

I've destroyed my old dizzy, so going to go back to original and get back to basics... factory original... at least then I'll be able to diagnose and look at factory literature to guide me in repairs and such. baby steps...

[Thipdar]

I've destroyed my old dizzy, so going to go back to original and get back to basics... factory original... at least then I'll be able to diagnose and look at factory literature to guide me in repairs and such. baby steps...

I've gotten a lot of advice over the years along the lines of "Why don't you upgrade this?" and "You should replace that". I'm pretty cautious about so-called "upgrades". My line of thought is generally "Are you kidding? I have enough trouble trying to figure out how it's SUPPOSED to be done!"

Different strokes for different folks...