Ignition wirng harness

Car is 71 duster 225 points. New points, condensor, starter relay. On going project, it had sat for quite a few years before I got it, got it running, tuned. Not yet insured so it only gets a 1/2 mile check out trip down the road. It does this occasionally. It is started and warmed up, I might move it and engines dies. I try to start and then nothing at the ign switch. I can wiggle the under column connection for the ign swith harness and it will start. OK . But soon as I try to check the bad wire)s) there, with test light probe, it wiggles enough and makes connection so that tells me nothing.
Since I ( and credit card) just spent $1500 at the dentist, I really do not want to order a new harness. My question is 1. Since it will just die I feel it is losing a connection somewhere to cause this. and 2. I want to jumper/ splice whatever the bad wire (s) are at that under column connection for the ign. harness: Is the culprit, the yellow wire to starter relay? The Hot wire there, OR the blue or brown ign, start/run wires??? I have cleaned this connector with a brass wire brush, applied some dielectric grease. I have run my large HOT (Red and Black) wires directly thru the bulkhead. I have cleaned the terminals at the amp gauge and do not want to bypass it.
I figure the part of bad under column connection is likely the end that is the ign. switch harness part. I don't want to lose the dash side of the connector, as I would probably order a new ign switch harness sometime in future. Would a jumper wire spiced in be reasonable cure for now, BUT which is my bad wire at the connector?????
Thanks

Yes, Had to do that to my 70 Duster, column connector by-pass will work till funds allow a replacement.
Actually it stayed that way for the next 2 owners before going to junkyard heaven.
I did that years ago.For the right wire look for a on line diagram. Mine was burnt right at the connector so tail tale sign was easy to find.

The column mounted switch has a short wiring harness made onto it. So you would buy a new switch with the wires. It connects to the cars harness under the dash. You found white plastic connector with about 5 large gauge wires and possibly 1 smaller orange wire. anyway... This connector would overheat, melt, loose connections. You have only 1 hot at all times wire there. The switch sends that power to the other wires. Aint no way we can tell you which is loosing connection. Power in at fault or power out at fault. We can guess... If you loose everything including the fused accessories at switch on I'll guess the power in is faulty. That wire comes from a weld splice and we have seen it melt all the way to the weld splice, short to other wires it taped in with, etc... If power in is always good, power out on yellow would run the starter even though it doesn't start due to brown or blue faulty.

Yes, when the car dies and I try to start, I GET no current at starter. I wiggle the under column connector and it will make connection where ever it is bad and start. I see nothing burnt at the connector. Which wire feeds current to the ign switch blue/brown wires? and yellow wire that goes from switch to starter relay? That large hot wire at connector? right?
The large hot wire at the connector is feed from 4 way splice right????

Yep blue and brown feed engine etc... yellow goes to starter relay.
So when you loose power to ignition switch, do you also loose headlights, brake lights? If so the fault is before the weld spice. Wiggling wires can move them far from your hand/origin of wiggle.

I will check to see if I have headlights next time it does it. May not do it for awhile!!!

OK, If the eventual break down is due to heat, you're playing with fire. People first find a melt down at bulkhead connectors. They delete those male female terminals, shove wires straight through. The next meltdown will have to be somewhere under the dash.

Update. Which of the ign. switch column wires are start and run? The brown is start and blue is run?????? I can unplug the brown wires at ballast and it will start and not keep on running.




Car starts every time now and run, won't die!!!!!

Another thing I wonder about. This car shows overcharge until the battery warms up. Then normal voltage. (MY mulitimeter died while back, and it is 2 hr to HF and really didn't want to buy a $30 at parts store.) I know, pitiful. Battery is almost new, and the alt. has been checked out at O Reilly to be good. It is 2 field type ,. I put the test light at the blue field wire on alt. and shows good steady current, I put it at the green field wire and it simply pulsates. I put test light at ballast, blue wire end of it, and get steady light , but at brown wire end it pulsates......

You need to get a meter and not a test lamp. Probe both sides of the column ignition switch connector and do a "wiggle" test. "Big red" is the power coming to the switch from ammeter circuit. "Big black" is switched accessory power. You really need two people so you can hold the meter probe, wiggle the connector, and be able to hold the key to "start."

Overcharge..........does it charge at higher than normal voltage? Run it with voltmeter hooked direct to battery, it should run 13.8--14.2 AFTER it is warmed up. Look in your service manual.........they give you voltage variance for cold. The VR IS TEMP sensitive. Otherwise check for the 'ol voltage drop problems in the bulkhead/ other terminals

67Dart273 said:

Overcharge..........does it charge at higher than normal voltage? Run it with voltmeter hooked direct to battery, it should run 13.8--14.2 AFTER it is warmed up. Look in your service manual.........they give you voltage variance for cold. The VR IS TEMP sensitive. Otherwise check for the 'ol voltage drop problems in the bulkhead/ other terminals

Click to expand...

When cold, sometimes it shows quite a bit of overcharge, 15.5 to 16 ( today I could rev it up and it would hit 17! v.) then after the everything warms up it gets back to charging about 14..3 or a little more. Occasionally when when I start it and all is cold before anything really warms it might show normal voltage right off. . I did take the big red and black wires out of bulkhead connector and feed them directly thru.

I will check at connector when I get another muli meter. This is the last booger I have to fix before I get it on the road to take its place as occasional weekend warrior!
Thanks for the help everyone.

If it sits for long periods with any draw on the battery, or if the starter turns a lot before it fires and runs the charging system would show higher during recharge. My 67 sits for weeks with the battery connected sometimes. Stereo memory the only draw ( not much ). If its going to sit for months I disconnect the battery. I always do spin it a bit before I move the throttle, set the choke, let is start and run. So the gauge shows higher output for a short time. It always recovers the battery and drops to normal operation though.

Over 16 is too much. Search for some of my threads on voltage drop

As 67Dart273 suggested I have read the articles on Voltage drop, I did find a few new ones I have never read. I will say thank you to all of you guys for the help. You spend a lot of time trying to help us electronically challenged!! ! When I see I will have a problem, I begin with all the recommend cleaning of connnnector, grounds, etc.
I admit I have never used a multimeter much for trying to find shorts, as connections under the dash are rally hard for me to get to at age 70. I been bucked off, run over, stomped on, neck and back broke, and had triple bypass last Sept! Oh yea, hit head on by and 80 mph drunk at age 25. He was driving big Lincoln!!! ha ( He won't do it again RIP asshole)