Ignition coil resistor in wiring?

[sam1904]

All,

 

I am upgrading from the vacuum advance distributor on my 76 02 to the IE Tii Mechanical Advance Distributor w/ Electronic Ignitor. I noted that it needs an inline resistor and have also changed from the black coil on the car (old and beaten) to a Bosch blue. I know that the Blue coil has an internal resistor and this is needed for the new distributor - my question is did the old dizzy need a resistor and if so is there one in line somewhere in the harness I need to remove??? (I wrapped my harness so it looks all pretty and didn't want to unwrap unless needed!)

 

Thanks

Sam

[John76]

My '76 (California Model) has a .9 Ohm clear color resistor wire connected from the #12 fuse to the + side of the coil.

The + side of the coil also has a black/red wire from the small, top #15 connection tab on the starter motor.

The starter motor sends  +12V to the  + coil (via the black/red wire) only during the starting (cranking) process.

When the ignition switch returns to position II (ign.) the + coil receives a lower voltage from the resistor wire.

These wires are all inside the big blue bundle full of all the emission control wires.

 

[Stevenc22]

76's have a resistor wire built into the blue wire harness. Find it and replace it with regular wire.

[HBChris]

And the resistor is the size of a small aspirin.

[Buckeye]

4 hours ago, sam1904 said:

I am upgrading from the vacuum advance distributor on my 76 02 to the IE Tii Mechanical Advance Distributor w/ Electronic Ignitor.

Why, I have read a lot good things about that distributor. I don not have one nor i am trying to knock down IE distributor.

4 hours ago, sam1904 said:

my question is did the old dizzy need a resistor and if so is there one in line somewhere in the harness I need to remove???

 Right in the middle of fire wall wire is blue sheathing should be able to find that resistor.

 

[sam1904]

Thanks all, I will go looking for it. Going to be a real PITA after all the cloth wrapping I did! What would be the effect if I did not. I assume as it is in series with the internal Bosch resistor it would lower current and degrade spark?

[Buckeye]

As you can see green wire connected to clear resistor wire.

Should be able to cut Clear resistor wire and tape it off at coil connection. See John76 diagram 

[sam1904]

Thank you so much,

Sam

 

[sam1904]

OK, I am a little confused - in the attached schematic is shows the resistor should be red?!

 

In all seriousness I assume 'resistor wire' just means a standard resistance wire with a resistor in line as shown in the photo and not that and a unique or specific gauge wire? If this is the case am I also correct I do not need to "replace the resistor wire'' but can rather just remove the resistor and re-connect the wire ends that leaves open?

 

Thanks

Sam

[John76]

Hmmm...not sure if there is an actual resistor between the green and clear wire, or if the clear wire is a resistance cable with XX Ohms resistance per XX length. Easy enough to check with a meter.

You don't want to connect a resistor wire to your Bosch Blue Coil (with internal resistor).

I believe our cars all came with the Black coils (no internal resistor) and utilized an external (big) resistor and relay (early cars) or the simple resistor wire and  separate black/red wire from the #15 tab on the starter solenoid (later cars). 

The full 12 volts to the coil (via the starter or resistor bypass)  during cranking gives a hotter spark to help ignition, especially during cold starts.

Once the "fire" is started, the voltage to the coil is reduced to extend the life of the coil.  BTW: I'm still running my original 44-year-old black coil with over 141K miles!

I think (just my thought) the internal resistor coils are used because newer cars are much easier to start, and therefore don't need the "coil life shortening" 12V boost.  

John

PS: I've heard stories about direct wiring 12-13V directly to a non-resistor coil to achieve a hotter spark, only to find the coil burns out every few thousand miles!

[Buckeye]

41 minutes ago, John76 said:

Hmmm...not sure if there is an actual resistor between the green and clear wire, or if the clear wire is a resistance cable with XX Ohms resistance per XX length. Easy enough to check with a meter.

At one time I disconnected resistance cable from green wire and other end at the coil and measured 2.1 ohm. Black coil (original one) has 0.9 ohms internal resistor. On later cars we are looking for total of 3 ohms of resistance. A new Bosch coil 00010 (direct replacement for original black coil) has internal resistance of 0.9 ohms.

1 hour ago, sam1904 said:

In all seriousness I assume 'resistor wire' just means a standard resistance wire with a resistor in line as shown in the photo and not that and a unique or specific gauge wire? If this is the case am I also correct I do not need to "replace the resistor wire'' but can rather just remove the resistor and re-connect the wire ends that leaves open?

There is no resistor in the picture provided above. That brass clip is only providing connection of green wire to resistance cable.

You gonna go with blue coil then you should remove clear resistance cable and attach regular wire, because blue coil has internal resistance of 3 ohm.

[sam1904]

Once again - thanks all and will do.

[HBChris]

There is an actual resistor in the middle of that clear wire.  Just remove it and extend with green wire to the coil. I posted a pic here a couple years ago.

 

 

Edited March 12, 2020 by HBChris

[sam1904]

Gotcha!

[Buckeye]

1 hour ago, HBChris said:

There is an actual resistor in the middle of that clear wire.  Just remove it and extend with green wire to the coil. I posted a pic here a couple years ago.

 

 

I differ with you. Look at my pictures for unmolested 1976 2002. There is no resistor.