I have a 1971 Buick Skylark Custom and I want to diagnose the health of my ignition circuit using my handy dandy multimeter. Specific questions I have are: 1. How to check for 12 volts at the ignition switch. 2. What fuses are in the ignition circuit and should be checked? 3. How to check the proper voltage drop across the resistance wire in the ignition circuit? (What voltage should it be at the coil?) 4. How to check for proper ignition voltage to the coil? Can anyone provide me proper voltages to check for at different locations in the circuit shown below:
I'll be watching this. I found my resistance wire when putting an original style distributor back in. I took an HEI out which is supposed to require 12 volts. But it was hooked up with the resistance wire. I have the new original style distributor back in with the crane electronic kit for 6 months now and haven't had a problem. Its always in the back of my mind that the resistance wire has 12 volts through it but Ive tried with the digital meter every which way and cannot seem to get a reading on it. So if someone answers, Id be glad to try it.
For a points ignition, connect a voltmeter between the + side of the coil and ground. Turn the ignition switch to the run position, but do not start the engine. The reading should be 5-5.5 volts. If the reading is 12 volts, the points may be open. Bump the starter to close the points and again look for 5-5.5 volts. Disable the ignition by grounding the coil wire. Have someone crank the engine. The voltmeter reading should jump up to at least 9 volts. Those are the only tests needed.
Larry would this work with the electronic ignition with no points to close? Ill try anything so I'll try it this weekend anyway
No, it won't. What I detailed above is the testing procedure for the resistance wire, and the bypass while cranking. The resistance wire drops the voltage to the points in the run position. The resistance wire is bypassed by the starter solenoid in the crank position. Electronic ignitions either work or they don't work, usually
So I can assume safely that my Crane kit is getting the proper voltage and stop loosing sleep that its getting 12 volts when it should be resisted.
I have a copy of the XRi instructions. According to what I have read, it needs resistance. I would test it the same way as a points system.
Larry I was just about to reply and say "I tried those instructions without any results" But I re-read them.... 1 - Disconnect any wires going to COIL- 2 - Reconnect battery. 3 - Turn the ignition key on but do not start the engine. 4 - Use a voltmeter as shown in Figure 2 and read voltage between COIL+ terminal and ground. It should be about 12 volts. 5 - Then momentarily jumper the COIL- terminal to ground. If voltage at COIL+ terminal drops below 8 volts, there is ballast resistance between the ignition key and COIL+ terminal. My mistake was on step 1! I was disconnecting everything from the coil, not just the - terminal. Ill have to check this again... and learn to read more accurately!
are the older crane units different? i put one in my impala 4 years ago and i pulled the risistor wire from the block on fire wall and ran a new wire. im sure it said that it needed 12 volts back then. ran it to florida and back on the power tour with no problems. just put one in the gs and it said use the risitor wire. now im wondering if i installed it wrong in the impala.
According to the instructions, it depends on the coil you are using. Some coils have internal resistance built in. In that case you do not need a ballast resistance.
Larry I did the test from the Crane instructions you pointed out. It worked. When I grounded the - terminal, voltage dropped for 5-6, So my resistor wire is in place. Very strange though, since the HEI that was in there was supposed to have 12 volts? Make no wonder starting has improved since putting an original Dist with the Crane it it.
