No Power in 74 Dart

[JGolden]

I'm going to feel like a moron when I finally figure this out but in the mean time... here I am.

I was doing some wiring repair on my 74 Dart. A few of the gauges didn't work when i picked it up so I tracked down the temperature sending unit wire and that for the oil pressure switch. Both wires had, for some reason, been cut short by the previous owner so I made the repairs but didn't actually have power running to either wire.

So, while tracing voltage through the temperature sending unit, all power went out in the car. Nothing popped or seemed to have shorted, it just worked one minute and then not the next. Everything is hooked up properly. The battery has a full charge. The starter relay seems to be working. I have voltage with a test light all over the vehicle. I know I'm overlooking something simple but I just can't figure out why nothing happens when I turn the key. No lights. Engine doesn't turn over. Nothing.

What am I missing?

 

[67Dart273]

Review the simplified diagram here in this article:

http://www.madelectrical.com/electricaltech/amp-gauges.shtml

The power comes off the battery at some point, probably your starter relay, goes through a FUSE LINK, through the BULKHEAD CONNECTOR, through the AMMETER and into the UNDERDASH HARNESS. Somewhere under the dash, taped up is the SPLICE in the harness. This is a multi-wire splice, welded and taped up by the factory, and the power feeds off that splice to the IGNITION SWITCH, the HOT BUSS in the fuse panel, and back OUT the BULKHEAD CONNECTOR to the ALTERNATOR

Check your ammeter connections, your fuse link, and bulkhead connector for melt/ damage.

You have a wiring diagram?

Here's one:

http://www.mymopar.com/downloads/1974/74DartA.jpg

http://www.mymopar.com/downloads/1974/74DartB.jpg

 

[JGolden]

Yeah I have the proper diagram for the vehicle.

Somehow, the electrical started working again last night but soon after quit on me again. I had checked some connections, turn the key, and everything worked. I then shut the car off, made a sandwich, and when I came back it just didn't work. :banghead:

I know the fuseable link is good and I'm pretty sure I had checked and tightened the connection to ammeter. I'll check it again but I'm starting to think that the bulkhead connectors might just be lose.

Idk. I'm sure I'll figure it out eventually.

Thanks for the tips and the simplified diagram. Actually helps.

 

[67Dart273]

About all you can do is to clip a test lamp in different spots --fuse link, bulkhead, ammeter, etc, and give it the wiggle test

I have found 4 cars in my lifetime (none were mine) in which the factory welded harness splice had FAILED. I've seen at least 2 cases where the factory ammeter wire ends failed

Order of appearance of the 'usual suspects' are the fuse link, bulkhead, and if you don't have power at the fuse panel "hot buss" then the harness splice. If it's just switched accessory related then the ignition switch/ connector.

 

[smalblokmopar]

I know you didnt mess with but have you looked at your ground from the engine to the frame. or the one that bolts to the rad support.

 

[TrailBeast]

Mine has a 30 amp fuse right next to the distributor behind the engine just a little towards the pass side.
Someone replaced the fusable link with a fuse.
Same results when that fuse blew, (Power everywhere but dash lights and engine)

 

[godfatherofchry]

Yeah I have the proper diagram for the vehicle.

Somehow, the electrical started working again last night but soon after quit on me again. I had checked some connections, turn the key, and everything worked. I then shut the car off, made a sandwich, and when I came back it just didn't work. :banghead:

I know the fuseable link is good and I'm pretty sure I had checked and tightened the connection to ammeter. I'll check it again but I'm starting to think that the bulkhead connectors might just be lose.

Idk. I'm sure I'll figure it out eventually.

Thanks for the tips and the simplified diagram. Actually helps.

wen you checked the fuseable link did you check in side or out.that is usually were the problem is..just tring to help..Artie

 

[JGolden]

Yep... it was the darn fusible link. I'm not sure how I got a good reading on it the first time but when I checked it again today it had obviously blown.

The only thing I'm left trying to figure out is why the Haynes manual indicated an 18 gauge link when it most certainly wasn't