No clue, please help

[WP29440SE]

the ECU works off a body ground. the mounting points where the box bolts to the firewall have to be good , clean , and preferably paint free contact points. the VR also depends on a firewall body ground in the same manner. make damn sure the battery to body, the battery to block , and block to firewall grounds are all good, clean, paint free and tight. just for shits, find your column ignition connector under the dash and make sure they are pushed together tight. I would also recommend you inspect and clean the bulkhead connections as well. they like to corrode in those areas

 

[The Rebel]

Loose connection at the bulkhead or loose connection at the starter relay?

 

[Aeronet]

Loose connection at the bulkhead or loose connection at the starter relay?

I don't know. Very possible.

 

[WP29440SE]

I don't know. Very possible.

quick story. I go out after a couple of months and fire up my 74 charger. starts right up. I run it around the block , park it back in the garage. I immediately try to start it, crank crank no fire..... well ****. got plenty of fuel. pull coil wire check for spark, ok , got spark. jump back in it starts right up. 2 weeks later , no start. pull coil wire, got spark, then it starts and runs. I start wiggling wires under the dash and it starts cutting out. I shut the thing off, unplug the the ignition connector from the column , squeeze it back together , and it hasn't missed a beat since.

 

[Aeronet]

quick story. I go out after a couple of months and fire up my 74 charger. starts right up. I run it around the block , park it back in the garage. I immediately try to start it, crank crank no fire..... well ****. got plenty of fuel. pull coil wire check for spark, ok , got spark. jump back in it starts right up. 2 weeks later , no start. pull coil wire, got spark, then it starts and runs. I start wiggling wires under the dash and it starts cutting out. I shut the thing off, unplug the the ignition connector from the column , squeeze it back together , and it hasn't missed a beat since.

Thanks. I'll try that this weekend.

 

[eldubb440]

points and condenser for the win

 

[Aeronet]

points and condenser for the win

It's a '73. Went through a condenser failure on my '69. The condenser was only a couple months old. Now I only change the points and keep an extra known good condenser in the car.

 

[Aeronet]

Did some tests: Hot Dist. Pickup 397 ohms
Cold 323 ohms
Bought a new distributor pickup 307 ohms
Book says pickup should be 400 to 900 ohms or 150 to 900 ohms
I'm going to say dist. Pickup is good.

Voltage at coil with ignition on:
Hot 1.2V neg.
Hot 5.5V pos.
Cold 1.27 neg.
Cold 5.28 pos.
Coil: primary 1.5 ohms
secondary 9.6k ohms
Coil is a new Standard Blue Streak. Replaced last weekend. Didn't solve the problem. Previous coil is an Accel 8140C that I've been using since the '90s. Primary 1.7 ohms
Secondary 6.74k ohms

 

[Aeronet]

Making progress. Coil voltage at pos. terminal should be within 1 volt of battery voltage. I now have a starting point.

 

[Aeronet]

I think I found the problem. Fusible Link that comes off of the starter relay.

 

[Aeronet]

I fixed the fusible link. Checked battery voltage with ignition on, car not running, after a short drive. 12.7 coil voltage was 5.83
Checked again: battery 12.43v
ballast resistor 10.41v
coil 5.87v

 

[Aeronet]

Tried to start car a couple of times and it didn't fire. I was also having a hard time getting a voltage reading on the coil and ballast resistor; it kept searching. Tried to start car a couple of times and it wouldn't fire. Checked the ballast resistor and it was hot. Replaced the ballast resistor and the car started.
I still don't really know what's causing the no start when hot problem.

 

[Demonic]

Oh boy - post 50, where you found that oxidized wire. Did you check the rest? Bulkhead, amp meter connections at the cluster? Main output wire from the alt? I'll bet you're due for an engine harness.

 

[Aeronet]

Oh boy - post 50, where you found that oxidized wire. Did you check the rest? Bulkhead, amp meter connections at the cluster? Main output wire from the alt? I'll bet you're due for an engine harness.

I checked the bulkhead and tried to clean it. Bulkhead looked fine. Haven't checked anything else. I'll do it tomorrow. I went for a short drive and felt the fusible link afterwards and it wasn't hot.
I agree. I need a new engine harness. I've been patching it over the years.

 

[Moparnocar]

Bulkhead is likely damaged too, best to do an actual voltage drop test on those circuits
https://www.google.com/amp/s/www.hagerty.com/media/maintenance-and-tech/measuring-voltage-drop/amp/

 

[Demonic]

http://www.evanswiring.com/catalog.htm

 

[Aeronet]

Bulkhead is likely damaged too, best to do an actual voltage drop test on those circuits
https://www.google.com/amp/s/www.hagerty.com/media/maintenance-and-tech/measuring-voltage-drop/amp/

Thanks. Will do. This car has always had some electrical gremlins that I never could quite eradicate.

 

[Aeronet]

http://www.evanswiring.com/catalog.htm

Thanks. Never heard of them. I'll probably get one here shortly. Prices are very reasonable. It's got to be better than some of the re-wiring I've done.
Thing is, it gets very hot in the engine compartment and the wires turn brittle after all these years. For example, last winter someone posted wanting to know what ohms a distributor pickup should have. I went out to check mine and when I tried to seperate the plug, the wires from the engine harness to the dist. pickup plug broke, they just came apart. I patched it a couple of weeks ago.

 

[Demonic]

Bill Evans is a great guy, makes his stuff by hand. I always look over the crimps, he's getting on in years. I've bought multiple times from him.
Go to Wal-Mart or a favorite hardware store, buy a small fire extinguisher. Really. Some clubs and organizations require one, like AACA.

 

[Aeronet]

Ok, Demonic, I will get a fire extinguisher. I do like to be prepared. If you look closely at the picture of the burned fusible link you'll see that I have repaired it before. It was a long time ago, early 2000s. I've also had trouble with the blower motor switch. The previous owner had by-passed it. I hooked it up again. Burned it twice. I by-passed it again because one more burn up and the switch is toast. I could smell it burning.
There is a short somewhere. I've tried to track it down, but so far I haven't found it.
It seems electrical trouble is common on '73 Chargers.