Can't start, burnt up some wiring

[stevethegray]

I've been trying to get my 74 started back up again for a few weeks now.  I put gas in the tank, got a new battery, new fuel pump and fuel filter.  I got the fuel pump and filter becaue I was not getting any fuel flow, the car would start if you put some gas down into the carb but would not stay running.   I didn't notice any broken fuel lines either.

Now after installing the new fuel pump and putting the alternator back on I still could not get it to turn over.

Worse than that as I was trying to crank it I see smoke coming from under the hood, I didn't realize what it was at first but then I saw that I was burning the sheilding off of some of the wiring. 

So that's obviously not good, I had to have effed something up. 

So what did I eff up?  How much will it cost me?    Where should I buy the parts? 

Thanks in advance

[Chryco Psycho]

Not enough info to diagnose , start taking the wiring apart you will see where it melted & what wires are involved , typically you can have problems with the main charging wire from the alt to ammeter or the fusable link

[stevethegray]

one of the wires that burnt up is definitely one of the ones that goes from the alternator back toward the distributor.   I didn't get to dig into it too deeply yet as I did this all at 10:00 last night. 

Lets speculate then.  Could I have done something wrong with the fuel pump that could have caused a problem with the distributor or something else?

[Highbanked Hauler]

no ,the fuel pump wouldn't have anything to do with the wiring.

[stevethegray]

What if I didn't get a good ground when I hooked the alternator back up?

[Chryco Psycho]

Electric or mech fuel pump , if electric did you use a relay , what is it wired to ?

[stevethegray]

Sorry should have specified, it was a good old fashioned mechanical pump.

[Chryco Psycho]

Hard to say what happened then , the only major wires in the area of the fuel pump is the 12v feed to the Alt field & the main alt output wire to charge the battery & feed the system , are any of the wires bare that could have shorted ,on the rear of the alt or on top of the engine , maybe corroson at the bulkhead connector caused heat there , very common problem . Check all the ground connections & make sure they are clean & tight .

[stevethegray]

Yeah I am going to have to get in there and start digging around and see what all is actually bad.  The only wire I saw for sure was one of the smaller wires that comes off the alternator. 

I'm not entirely pumped about having to put in new wiring now.  Do they make OEM replacements or do you have to get in there and just attaching ends and cutting your own wire?

[Chryco Psycho]

not sure for 74  repairing the wiring can be done cleanly .

[stevethegray]

Cleanly I don't care about right now, I'm shooting more for "running".  Down the road I want to drop in a new motor anyway.

[stevethegray]

Now I got some visual aid. 

In the first picture you can see the wire that comes from the alternator that fried up.

In the second picture you can see that this wire near the solenoid is quite exposed, I suspect this is where the problem came from, as it seems to have melted through the shielding of the nearby wire harness and probably made contact with the wire that goes to the alternator and shorted it out.

The third picture shows the location on the firewall where it all seems to run into.  Thankfully none of those wires appear to have taken any damage.

I don't think anything I did while changing the fuel pump would have had an impact here, it was just the last thing I happened to do.

So what should be my course of action here?

[stevethegray]

Well here is what I did.  I got some new wiring and terminals and replaced the burnt up wiring. 

With the exception of some better soldering that I need to do I got that all in there as you can see in the pictures. 

I am still not starting, and now It is not even turning over when I prime the carb with gas, before that wire fried I was able to do that.  I suspect that I am now not even getting spark, I'll have to test for that as soon as I get a chance.

So I am trying to figure out what caused that wire to fry in the first place.  Look at the pictures, you can see the wire I replaced is the bright blue one with the yellow electrical tape on it.

One end of that wire goes to the alternator, then into that bracket that is near the ignition coil and choke, then it goes back to where it is soldered in with 4 other wires.

does anybody know what purpose this wire serves, I am hoping that will help me figure out why it fried up in the first place and hopefully lead me to why the car isn't starting.

[stevethegray]

I'll even accept speculation at this point, anything

[Dino]

What type of ignition do you have?  Points or electric?  Did you replace thet ballast resistor the blue wire hooks onto?  Chances are that one went when the wire went poof.  Can yuo look under the dash to see if anything else went bad?  When something like this happens it tends to melt a few things in the bulkhead so definitely check those connectors and test for continuity.

[stevethegray]

I just ordered a new ballast resistor, so that'll take a few days.  I didn't notice any other burnt up wiring, but I will certainly get in there and look around more closely under the dash.

I think its a points based ignition, I'm not sure I thought 74 was right around when they started using electric.  (Now its time to sound like a n00b)  How do I tell?

[stevethegray]

Electric ignition became standard in 1973, so no points.

[randy73]

Sounds like you put the field and ground wires on reversed. You need the correct harness or use a wiring diagram to make your own.

PM me your email and I will send you the engine wiring diagram.

BTW: you can ballast resistors at any parts store.

[stevethegray]

I have the wiring diagram printed out.   My resistor didn't get here yet, will probably show up tomorrow while I am Carlisle.

I don't see how the wiring could have been wrong when the burn up happened as the wiring was still in the same configuration as it was when I last used the car as a driver.  I hadn't touched the wiring until this happened.