1971 F100 Needs Points Again
Thread Starter
|
New User
Joined: Mar 2009
Posts: 16
Likes: 0
1971 F100 Needs Points Again
I somehow burned up the points on my 71 F100 360 motor. Do I need to use a Ballast Resistor on the positive lead to the coil or should I just replace the points and see how long they last? I think the old set was from 1971 because it still had the white push-on type connector for the coil wire.
I've used the Pertronix Ignitors before, But had one fail and caused a "late" ignition that blew up a muffler, so I'd rather go with points. Any suggestions?
Thanks,
Joe
I've used the Pertronix Ignitors before, But had one fail and caused a "late" ignition that blew up a muffler, so I'd rather go with points. Any suggestions?
Thanks,
Joe
Lead Driver
Joined: Aug 2003
Posts: 7,592
Likes: 10
From: **** hole San Jose ca.
You should check the voltage on the resistor wire at the coil, it should at be about 7+-9 volts. The first generation of Pertronix Ignitors would start over heating after one minute. Its was a known problem if ign key was left in the (on) or run position with out the motor running. Many guys it this to just listen to the radios they don't bother to turn it to the left for the ACC= Accessories which bypassed the ign power to the coil no over heating the the Pertronix unit. The Sec. Gen of the Pertronix Ignitors corrected this problem. orich
Thread Starter
|
New User
Joined: Mar 2009
Posts: 16
Likes: 0
Thanks Orich, I did see that they have a 2nd and 3rd generation Pertronix unit.
When you say "resistor wire" you mean the wire that connects to the positive side of the coil correct? I do not have a resistor on that wire as of yet. Should I? or is it in the wiring before it comes through the firewall to the 3 connector plug(coil,oil,temp)?
Bless you for your service then and now sir.
When you say "resistor wire" you mean the wire that connects to the positive side of the coil correct? I do not have a resistor on that wire as of yet. Should I? or is it in the wiring before it comes through the firewall to the 3 connector plug(coil,oil,temp)?
Bless you for your service then and now sir.
Lead Driver
Joined: Aug 2003
Posts: 7,592
Likes: 10
From: **** hole San Jose ca.
Yes the resistor wire coming to the + coil side, it's built into that wire from the ign switch. So you just hook up a voltmeter. One lead to ground & one on the +side of coil. You can do this even while the motor is running. Also the points disty cam should be cleaned and re-lube to maintain points gap longer. This slows the rubbing block wear by doing this. Also check for any side movement of disty shaft. If play is found then time to replace whole distributor or which is about 50 bucks or go back to Pertronix unit..my 2cent .
orich
orich
Cranky Old Guy
Joined: Mar 2008
Posts: 3,562
Likes: 6
From: Raphine, Virginia
I somehow burned up the points on my 71 F100 360 motor. Do I need to use a Ballast Resistor on the positive lead to the coil or should I just replace the points and see how long they last? I think the old set was from 1971 because it still had the white push-on type connector for the coil wire.
I've used the Pertronix Ignitors before, But had one fail and caused a "late" ignition that blew up a muffler, so I'd rather go with points. Any suggestions?
Thanks,
Joe
I've used the Pertronix Ignitors before, But had one fail and caused a "late" ignition that blew up a muffler, so I'd rather go with points. Any suggestions?
Thanks,
Joe
Thread Starter
|
New User
Joined: Mar 2009
Posts: 16
Likes: 0
OMG Is this a sign?
Well I replaced the points. It turns out that they were only a few thousand miles old. Only the connecting wire from the coil was from 71. I did notice however that the contacts inside the dist. cap were worn on one side. They actually had grooves in them from where the rotor had sliced into them. I'm hoping that the rotor or cap was mis-aligned and it is not the whole dist that is at fault.
I get 12.3 volts at the coil, so I got a ballast resistor that I am going to wire in when I put on the new cap, rotor and condensor. I hope that will do the trick.
Thanks for everyone's help in stopping the shakes.
I get 12.3 volts at the coil, so I got a ballast resistor that I am going to wire in when I put on the new cap, rotor and condensor. I hope that will do the trick.
Thanks for everyone's help in stopping the shakes.
Cranky Old Guy
Joined: Mar 2008
Posts: 3,562
Likes: 6
From: Raphine, Virginia
Well I replaced the points. It turns out that they were only a few thousand miles old. Only the connecting wire from the coil was from 71. I did notice however that the contacts inside the dist. cap were worn on one side. They actually had grooves in them from where the rotor had sliced into them. I'm hoping that the rotor or cap was mis-aligned and it is not the whole dist that is at fault.
I get 12.3 volts at the coil, so I got a ballast resistor that I am going to wire in when I put on the new cap, rotor and condensor. I hope that will do the trick.
Thanks for everyone's help in stopping the shakes.
I get 12.3 volts at the coil, so I got a ballast resistor that I am going to wire in when I put on the new cap, rotor and condensor. I hope that will do the trick.
Thanks for everyone's help in stopping the shakes.
Trending Topics
Posting Guru
Joined: Mar 2006
Posts: 1,182
Likes: 1
Don't be so quick to do that. Unless it was removed, it is still in place. When points are open, you will read full battery voltage. Only when the points are closed will you be able to see the reduced voltage. You could also just ground the neg side of coil and you should read the reduced voltage.
why will you see full battery voltage when the points are open, even if the resistor wire is in place?
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
10 Things Every Truck Owner NEEDS (2026 Edition)
Michael S. Palmer
Rezvani's Latest Post-Apocalytic Monster Is a Ford F-150 Raptor Underneath
Verdad Gallardo
Top 10 Most Expensive Ford Trucks Ever Sold on Bring a Trailer
Joe Kucinski
2027 Ford Super Duty Buyer's Guide (Every Model, Engine, & Package)
Brett Foote
Top 10 Ford Truck Tragedies
Joe Kucinski
AEV FXL Super Duty - the Super Duty Raptor Ford Doesn't Make
Brett Foote
Lobo Vs Lobo: Proof the F-150 Lobo Should Be Even Lower!
Michael S. Palmer
Ford's 2001 Explorer Sportsman Concept Looks For a New Home
Verdad Gallardo
10 Best Ford Truck Engines We Miss the Most!
Joe Kucinski
Junior User
Joined: Oct 2011
Posts: 71
Likes: 1
From: Fort Wayne
Ok, sorry to bring up an old thread, but I've done a search on this, and while the resistor question has been covered a bazillion times, I haven't seen an answer that will get through my thick skull. I installed a Pertronix Ignitor (first series, I'm guessing, since it didn't have any numbers after it) in my 68 F-100 with a 240, along with an MSD Blaster 2 coil. I didn't find any separate resistor (this was before I knew about the resistor wire), so I hooked the coil up as it was from the factory, and ran the red wire from the Ignitor to the + on the coil, and the black to the – on the coil (as the instructions said). It runs like a champ. Now for my question: is this wired correctly, or is it a problem waiting to happen? I haven’t had a single problem yet, but I don’t want to burn anything up. In fact, it runs so great, I got a kit for my ’68 Galaxie with a 390. I just want to make sure I get it wired correctly. I’ve read the directions, looked at the digrams, searched through the archives, but I haven’t found a post that just tell me what wire to attach where. Any help is greatly appreciated.
Thread Starter
|
New User
Joined: Mar 2009
Posts: 16
Likes: 0
I have used the Petronix units in other old Fords and they work great, unless they fail. My guess is that the one I had that failed years after I installed it, was a first generation unit. Just follow the instructions provided.
BTW thanks for all the help, the truck is running fine since the repair.
BTW thanks for all the help, the truck is running fine since the repair.
Posting Guru
Joined: Mar 2006
Posts: 1,182
Likes: 1
Ok, sorry to bring up an old thread, but I've done a search on this, and while the resistor question has been covered a bazillion times, I haven't seen an answer that will get through my thick skull. I installed a Pertronix Ignitor (first series, I'm guessing, since it didn't have any numbers after it) in my 68 F-100 with a 240, along with an MSD Blaster 2 coil. I didn't find any separate resistor (this was before I knew about the resistor wire), so I hooked the coil up as it was from the factory, and ran the red wire from the Ignitor to the + on the coil, and the black to the – on the coil (as the instructions said). It runs like a champ. Now for my question: is this wired correctly, or is it a problem waiting to happen? I haven’t had a single problem yet, but I don’t want to burn anything up. In fact, it runs so great, I got a kit for my ’68 Galaxie with a 390. I just want to make sure I get it wired correctly. I’ve read the directions, looked at the digrams, searched through the archives, but I haven’t found a post that just tell me what wire to attach where. Any help is greatly appreciated.
to check- fire up the truck and check voltage at coil +.
if you get ~9v, you're all set.
if you get full battery voltage, its a problem waiting to happen.
Junior User
Joined: Oct 2011
Posts: 71
Likes: 1
From: Fort Wayne
the directions for the first-generation Ignitor are very clear- if your system has a resistor wire, you are supposed to leave it in place.
to check- fire up the truck and check voltage at coil +.
if you get ~9v, you're all set.
if you get full battery voltage, its a problem waiting to happen.
to check- fire up the truck and check voltage at coil +.
if you get ~9v, you're all set.
if you get full battery voltage, its a problem waiting to happen.
Lead Driver
Joined: Aug 2003
Posts: 7,592
Likes: 10
From: **** hole San Jose ca.
The problem with the first-generation Ignitor is if you leave the ign. key turned on while the engine is not running for a few minutes, as it will load up and over heat and cook itself. Some guys her had the unit even melt the plastic some. The 2nd & 3rd generation ones have a built in shut off.. I've used all 3 of the drop in Ignitor unit. Liked the 3rd the best..orich