Truck broke down, HELP!

[NCannon]

Hey, my 69, 250 4 speed stranded my girlfriend this morning. Here's where I know.

It had driven ~40 miles already, and was running well, good temp, oil pressure, etc. She came off the freeway, stopped, made a turn, stopped and it stalled and never re-started.

She got a tow from a diesel mechanic who did some quick work and told her it had no spark. I came by later after the guy had left and came to the same conclusion.

I ran a wire from the positive to the positive of the coil and got no spark, the coil, coil/plug wires, points, cap, rotor, and plugs are all relatively new. I put all that stuff on in june/july when I got the truck.

I don't know if there is a ballast resistor, or a fuse that could have blown that could cause this, I was at work and basically had a screw driver, so I was only able to check little things, the point gap looked REALLY small, so I adjusted that, nothing, again I hot wired the coil, and got nothing. I'm probably going to start with a new coil. The existing one is an MSD dealy, but if I don't actually have a ballast resistor and have been running 12 volts to it forever it could be bad, do these things just fail instantly like that?

I'll come back tonight with a multi-meter and some electrical stuff and tools probably a new coil but any pro-tips on this could be good. I just tried all of the "tricks" I could think of and got nothing. Thank you guys.
-Nate

[cdowns]

does the truck have the original points? have they been cleaned and gapped and the dweel set recently??

[NCannon]

In probably early July I replaced coil, coil wires, cap, rotor, POINTS, condensor, and plugs. The truck probably has a few k since then. I set the points and used a dwell meter at the time. I'll check that for sure, I didn't have any tools or diagnostics available to me when I ran out there.

Apparently it died "like I turned off the key" no stumbling or anything.

the points looked really tight when I went out there, and I reset them with a business card, and still got nothing.

I got no spark at a plug and I got no spark when I tried from the coil. I got nothing when I wired 12V directly to the coil. I'm thinking coil, I'm wondering if this sounds crazy and if they fail instantly. I'm also reading about a ballast resistor and I don't see one, where is it and do I need it? The wiring seems all original but I haven't had it THAT long.
-Nate

[Longhorn 70]

Measure this.....
Key on not cranking, - around 9V to the plus side of coil
Points closed, - side of coil (dist side) low ohms to ground
Points open, - ∞ resistance to ground

IF you want, key on and quickly jump dist side of coil to ground and pull off immediately. You should get a spark at the coil wire.

[NCannon]

Right, that's what I tried and I got nothing from the distributor side of the coil to the engine block. I pulled the coil wire off the dist, stuck my screw driver in there and bumped it, and got nada. Ran a "hot" from the + battery to the + coil and cranked... nada.

I'm heading home from work in a few hours, going to pick up my multi meter, a new coil, dwell meter, some wiring stuff, and tools. I figure if it's electrical I'll get it sorted, if not, well... It's legally parked. I'll figure something else out. I'm kind of curious, can/do coils fail instantly like that?

Thank you.
-Nate

[cdowns]

they did not have ballast resistors // they had a resistance wire going to the coil it looks to be a thicker pieceof wire covered in a sort of clothlike material (and the yellow wire has it's junction near it) and it is in the wiring harness from the firewal ljunction box near the steerin column

[NCannon]

Right, I did some more research after posting and found that out. So while cranking I should see 12v at the + on the coil and with the ignition on I should see 9ish?

Then if I jump the coil and it's say... infinity, that's bad. I'm just trying to figure out how it was all hunky dory and then bam... nada. I'll check all this, hopefully the coil just pooped out, but I have diagnostics to check other issues. Thank you gentlemen!

[Longhorn 70]

The coil is 2 coils. It's kind of like a transformer. Make sure you have continuity between the + and - on the input of the coil should be fairly high maybe 10KΩ and the - and center conductor should be low around 4Ω. This is from memory so check center to both sides of the input and look for one to be low.

[Ricks1971]

might be as easy as changing the condenser. I have a truck do the same thing and I changed everything and the condenser last and that's what was wrong?

[mcbassin]

I can't help with the current problem but my recommendation is to ditch the points dizzy as soon as you can and go with an electronic ignition. Those things will strand you just when you least expect it. Electronic ignition is cheap reliability. good luck.

[NCannon]

The condensor was replaced in mid july with the rest of the ignition. The truck is driven mostly on weekends for home depot and garden center runs. And when I'm feeling like not listening to a radio or being comfortable So maybe 1000-1500 miles since july. I drove it about 40 miles yesterday and it had maybe 40 miles today when it suddenly died.

I guess I'm wondering, without really getting too into it, the coil and the condensor seem to be the only parts that would fail instantly. I can't see how mechanical points would just STOP working and not be obviously bad, same goes for cap, rotor, wires, etc. Am I wrong? I'm sure there are instances where this happens, but well. At this point I just need to get the truck home and then I can park it for the winter

[Longhorn 70]

points fail in several ways.

Screws slip
rubbing block breaks or wears down
open condenser causes a peak on one contact that can short them or decrease dwell
pivot insulator breaks, cracks or causes a short....
wire breaks at connection causing short
wire connector fractures causing short

[NCannon]

okay well, in trouble shooting I turned the engine over a few times and the points seem to be operating, mechanically at least. I just never saw spark at a plug or after the coil. I'm going to start at the coil and work my way forward. Ugh. What's so frustrating is that it stranded my GF and not me!

[JointTech]

i guess the real question is why is your GF driving the old beater and you have no trouble getting to and from work and to pickup your broken truck in what I assume is another vehicle?
Not trying to be rude but I'd never put my wife in my truck by herself. I dont even like her driving my 04 Xb because it has close to 200k on it even though it runs like a top.

[john]

Don't discount the condensor just because it was replaced in July. I saw one fail on a truck one week old.

[zeldman]

One way to test the coil is to take it off, shake it and listen for a sloshing sound. If it sloshes, it may be bad. Yes, a coil can fail that bad, so can a condenser.

[VetteVet]

Here's a simple way to test just the coil.
Pull the wires off it on the plus and negative terminals and run a hot wire from the battery positive or the alternator large post to the plus side of the coil. Then run a wire from a good ground to where it will reach the negative side of the coil.

Then hold the high voltage center wire near a good ground and tap the small negative wire to the negative post on the coil. If the coil is good you should see a nice blue spark from the high voltage lead to ground. If you don't want to hold the zapper wire then put a known good spark plug in it and let the plug threads touch a good ground, and watch for the spark, while you tap the negative wire on the coil.
This isolates the coil from every thing else and tells you if the coil is good or bad.

[ItsRandy]

I had a coil fail on me once, it acted like it ran out of gas. Power fell off then motor died.

I had a condenser fail on me once, it acted as if out of time. Backfired out the carb then out the exhaust but still had spark.

Sounds kinda' like the coil failed to me...but I could be wrong.

[Mister-B]

Originally Posted by JointTech

i guess the real question is why is your GF driving the old beater and you have no trouble getting to and from work and to pickup your broken truck in what I assume is another vehicle?
Not trying to be rude but I'd never put my wife in my truck by herself. I dont even like her driving my 04 Xb because it has close to 200k on it even though it runs like a top.

His truck isn't exactly a beater, and if you've followed his other posts, he's dating a desirable chick that actually likes to drive his truck, and willingly takes it for things that only a truck can do

[Longhorn 70]

Originally Posted by ItsRandy

I had a coil fail on me once, it acted like it ran out of gas. Power fell off then motor died.

I had a condenser fail on me once, it acted as if out of time. Backfired out the carb then out the exhaust but still had spark.

Sounds kinda' like the coil failed to me...but I could be wrong.

I had a GF fail on me once. With a truck like ours... I replaced her

[jorgensensc]

Originally Posted by JointTech

i guess the real question is why is your GF driving the old beater and you have no trouble getting to and from work and to pickup your broken truck in what I assume is another vehicle?
Not trying to be rude but I'd never put my wife in my truck by herself. I dont even like her driving my 04 Xb because it has close to 200k on it even though it runs like a top.

Really? You jumped to major conclusions. I have a '72 suburban daily driver that I haul all 4 of my kids in. And yes my wife drives it too. There is nothing wrong with older vehicles if they are maintained. Sounds like the op maintains his vehicles well. Even new vehicles randomly break down. YOU won't even let your wife drive your '04 vehicle, even though it 'runs like a top'. So hat do you do? Buy her a new vehicle every year?

[jjzepplin]

Did a full tune up on my old 70 and ran like a clock. 3 months later ,on the way to work, it started sputtering and died. Long story short it was the new points. The kind that had the condenser integrated. Replaced them and it ran like a clock again. Has an HEI now though.

[Longhorn 70]

One more thought...do you have a tach? I had one short 20 years ago and strand me.

[NCannon]

Thanks for all the replies. Seems like the coil did the trick. It was still showing 12V on the + side even while running, so maybe I don't have a resistor wire, or something. It's not obviously been replaced.

My girlfriend was taking the truck to pick up a sofa. The truck has run like a top since I've gotten it, I never really considered it a liability. Also, if you want to come tell her she can't drive the truck because she's a girl, I'll drive you to the hospital... in the truck.

Thanks again guys, drove it home and parked it. It's cold and crappy here today, I'm not sure when I'll get around to troubleshooting the reason behind the high voltage at the coil.
-Nate

[JointTech]

Originally Posted by jorgensensc

Really? You jumped to major conclusions. I have a '72 suburban daily driver that I haul all 4 of my kids in. And yes my wife drives it too. There is nothing wrong with older vehicles if they are maintained. Sounds like the op maintains his vehicles well. Even new vehicles randomly break down. YOU won't even let your wife drive your '04 vehicle, even though it 'runs like a top'. So hat do you do? Buy her a new vehicle every year?

its not the years, its the miles. And yes I don't let her drive a car with 100k miles. She gets a new one every 3-5 years. Oh and I don't buy her anything. She makes way more than me and wears the pants in this family. haha. I haven't had a new vehicle break down in 20 years. I did run out of gas in her mini once. stupid single gauge I couldn't see the gas or the idiot light.

I meant no offense to the OP or his "desirable" girlfriend, whatever that means. I do know 95% of the trucks on this forum aren't fit to be daily drivers much less something to send your GF on a roadtrip with. I went with that assumption. so apologies if any toes were stepped on.