[import_crusher]

i purchased a unlite distributor, setup the wiring as in the diagram with the ballast resistor, but i'm still showing just over 12 volts at the trigger wire (green).
what could i be doing wrong?

Thanks!

 

[lluciano77]

What is the at the load side of the ballast resistor?

What is the voltage at the line side of the resistor?

The line side is the battery side, the load is the distributor side.

You should show a voltage drop across the ballast resistor. Somewhere in the 3 to 4 volt range.

Do you have one wire hooked up to one side, and the other to the other side? They can't be connected on the same side.

For Mallory distributors you want 8 to 9 volts at the load side of the ballast resistor. 10 is the max you can run.

 

[import_crusher]

i just set it up about 3 hours ago - ran the car for the very first time for about 45 seconds, bbc
anyway, if i recall correctly
i had 12.59 volts from ignition switch (line side?) into ballast
checked volts at positive on coil 12.59
negative side going to distributor also showed 12.5
i ran it like the diagram - ignition line to ballast, from ballast to positive,red line from distributor to positive on coil, brown is grounded on aluminum manifold and green runs from unilite module to negative on the coil
but i don't see any drop in voltage
module and ballast are brand new
actual distributor and promaster coil are used
does this answer everything?

 

[lluciano77]

Go to your local parts store and get another ballast resistor. See if it reduces the volts down to 8 to 9.

It will run with the voltage too high. Don't get tempted to run it that way. It will eventually burn up your Unilite module.

The other option would be to install a capacitive disharge ignition. :thumbup:

You don't have to run a ballast resistor with those. The Unilite is wired to the box in that case. The voltage conditioned to work with the Unilite from the spark box.

Of course, the ballast resistor is only $5 at the parts store.

 

[enjenjo]

I run 2 ballast resistors on Unilite ignitions, the one in my car has been that way for 12 years with no problem. checking a ballast resistor has to be done under load to get the correct reading. the voltage reading will be initially high, and drop as it warms up.

 

[Siggy_Freud]

negative side going to distributor also showed 12.5

I didn't think that the negative side of the coil should show any amount of voltage. Isn't it the signal side that when the ground is made and broken (via the rotor/cap/module) it "signals" the coil to fire?

 

[import_crusher]

i'll check it again tomorrow. maybe i'm mistaken
i'll post and let you know
thanks for the help
i also had just dropped the distributor and set it at number 1 tdc, so the module eye was open, maybe the reason for the voltage?
i forgot to take the rotor out and block the eye with a credit card or something and then taking a voltage reading

 

[NXS]

Hi Siggy,
The Neg post of the coil will show voltage with KOEO, no points.

Luc77 is correct as I have had more than one Unlite module fry and at nearly $100 a pop a trip to the parts store for another ballast is the correct way to go.

Great distributors, I've had a few but now I will only run HEI unless there is no clearance for the firewall or blower. MSD capacitive discharge systems are hands down the best in that case.

 

[import_crusher]

ballaster is not grounded properly. does it need to be grounded to check for proper voltage?

 

[red65mustang]

to read the V after the resistor

remove the wire from the resistor to the coil.

alligator clip the volt meter from the resistor coil side to the coil.

with the motor running* at idle** it should read 8-9 V or go get another (Chrysler) resistor

*don't try to measure it just cranking the starter, you may have a 12V line from the starter solonoid to the coil to help the motor start

**less than ? 800rpm,
if your choke is on =1200rpm+ =alternator is overcoming the resistor =12V?

 

[lluciano77]

The ballast resistor doesn't need to be grounded. One test lead needs to be grounded.