They look a bit frazzled, are they new?? They look like they're getting hot.
Do they close nicely face to face?
0.2 ohms in your hand sounds ok (off the truck) but that's at very low current of course.
What if you put some current behind that? Replace the coil with a lamp bulb for example - does it flash when you turn the engine or do the points just get hot?
Give them a good sandpapering or better still replace with new.
The crimped wire connection also looks a bit furry - has the wire been replaced?? Maybe worth running the soldering iron into it
Unfortunately, no. I've done more testing, but nothing is makes sense or standing out.
On friday, I decided to "bench test" the points. I removed the points from the distributor and mounted them to a wood block, basically using them as a switch and isolating its ground. I tried the following every possible combination of grounds (to coil and points) and hot lead to the coil (using switched ignition power and direct to battery +).
1. I directly connected the coil - to the points cable (white cable), still keeping the condenser wired in parallel. In this configuration, I tried grounding to the battery, engine block, frame, cabled to distributor housing, and bolted to distributor housing - with both coil + to battery + and to switched ignition. I was using the spark strength tester that I have mentioned previously. In all configurations, results were the same. There was little to no change in spark strength, but the spark strength still seems low to me. The tester indicated less than 20KV. Everything I've read said spark is typically 30-40KV. I tried the spark tester on two other, more modern, vehicles and got 35+KV.
2. I repeated all of the same tests as in (1) but took the points out of the equation and used the touch and go wires as the switch. Spark strength was the same.
2. I then bolted the points back into the distributor and checked for spark with cranking the engine. I tried this test, as well, in all possible configurations: coil - through dizzy post, coil - directly to white points cable, extra ground wire to ground the points plate to the block / frame, extra ground wire to ground dizzy spring plates to block / frame, all tests with both + battery power and ignition power. I get almost no spark from the tester when using the engine cranking to actuate the points...I certainly don't get the spark at the 20KV I was getting when manually actuating. At this point, I was starting to suspect maybe the battery was getting weak and the starter was drawing too much current from the weak battery.
3. So, I decided to quit for the night and waited overnight for a fully charged battery (battery is only 3 months old, fyi). I hooked everything up and repeated all of the same tests and all results were basically the same (it actually seemed like spark was slightly weaker...???). I tried cranking the engine to get spark, both with ignition power and battery + power to the coil and...yep, same result. I couldn't get a noticeable spark, unless maybe if I adjusted the spark gap tester down to 10KV, or less. Even then, it's inconsistent. <10KV is like super small engine territory (like small gas lawn tools).
NEXT STEPS
The only other test I have left in my bag is to take the points out of the equation again and replace them with a small micro-switch. This micro-switch will better mimic the action of a healthy set of points. The wire "touch and go" technique works, but is a bit inadequate and doesn't fully mimic the switch action. I'll hook up the switch in place of the points and run all the same tests: different power sources, different grounds, etc. If the spark is stronger, I'll replace the points and see what happens. If spark is the same...I'm a bit lost.
If the results are the same with the micro switch, I only see two possibilities:
1. The 20KV spark from the bench testing is actually adequate and there is something going on with the power to the coil or grounding while the starter is cranking. However, if this was the case, I would have expected the truck to remain running in the past when I was finally able to get it started.
2. There is something else going on in the wiring, when ignition on, that is somehow effecting the spark strength that I am just not seeing...even though I seem to be getting enough voltage to the coil + from ignition when switched on (I was getting between 11.9V and 12V with a fully charged battery that directly read 12.7V).
CHANGES SINCE LAST WEEK
1. I redid all of grounds last week, per Coolerman's recommendations. I used overkill wiring size, replaced the battery terminals, added extra ground straps to a bunch of critical locations and all ground paths show negligible resistance (between 0 and .2 ohms).
2. I started to second guess my stereo and it's power draw with ignition on. I only read a few mA draw when ignition was off (so it isn't shorting anywhere), but I thought I would disconnect it just in case...remember my arcing in the ignition switch?? I noticed no observable difference in spark strength with it totally disconnected from power. Keep in mind that the stereo was the very first thing I did to the truck when I got it and drove it fine for 5 months before the issues started.
3. I traced the 'always on' wire circuit (large white / blue wire) and it all seems to be connected properly. I was wondering if there was a minor short somewhere in this circuit since this wire connects to so many things (ignition, alternator, regulator, fuse panel, not to mention all the times it splits). I found no inconsistencies in resistance anywhere and it all appears to be connecting properly.
QUESTIONS
1. Can someone remove their plastic steering column shrouds and observe if they have an arc inside the ignition switch when switching from Ignition On to Off? I assumed this arc had something to do with the stereo power draw to the amp when turning the ignition on. However, with the entirety of the stereo removed, the arc is still present. It's hard to tell just how bad it is, or if it's even a problem. If I remove the ignition switch from the steering column and then turn the key, I don't see the arc. This could just be because it's not as easy to see when the light isn't reflecting off the metal interior of the steering column where the ignition switch mounts. It's all plastic...doesn't seem possible that it is shorting anywhere in the column. Regardless, ignition behaves the same with it out of the column versus mounted in the column. Could somebody please check their ignition switch to see if it behaves this way?
2. Does anyone know what I might be overlooking in the wiring? I'm truly stumped. Everything seems appropriate and I'm nearly certain that nothing in the wiring has changed since I purchased the truck (aside from cleaning up bad connections).
3. I keep coming back to the Ignition wire circuit and a possible short. Could somebody measure the voltage they get at the coil + with ignition on? Also could somebody check for any resistance (continuity) anomalies between the black/yellow wire and the positive circuit and also the ground circuit?
Thanks. Even though the points seem fine and are nearly new, I just ordered another set anyway. I still don't think it is the problem but I wanted to have them on hand just in case.
