My van had no spark.

We traced all the harnesses back hoping to find a split wire and we did!

Behind the power brake booster was 3 of these things and we don't know what they are.

Can anyone help?

yep,thats a fusible link.

_________________
81 LeBaron Salon,88 5th ave,79 Aspen SE wagon,79 W150
Don't worry, nothing is going to be alright.

That's what we were leaning towards lol.

Can't find a diagram for this electrical system though.

It goes into a pyramid type connector that is hardwired three in (this being one of the three) and one out.

So, it would probably be wise to NOT just jumper the break then I guess.

Treat it like a fuse. I think it can be replaced with a slow-blow fuse? Comments anyone?? P

_________________
"Louise", a 1976 Dart Custom project, (now sadly reverted to being just an "organ donor" to our other project Darts.)

I recall reading after a certain period, perhaps mid-late 80's, mopar replaced fusible links with maxi fuses. On the maxi fuse package I bought it also made mention of fusible link replacement.

I would just replace with same gage fusible link as it will be a lot cheaper than installing fuse holders and fuses. If you are rewiring the whole car, and making modifications to original harness design than fuse substation may be more applicable.

Fusible links are sized four wire gage sizes smaller than the conductor they are protecting. Example: 10 gage conductors would require a 14 gage fusible link, or a 14 gage conductor would require an 18 gage link. Fusible links utilize a special nonflammable insulation, and dedicated copper wire, do not make your own link from standard wire, you won’t be protected, and possibly cause an insulation fire.

Before you replace that and other melted fusible links make sure to identify the problem that caused them to fail, and fix it, or you will melt more wire and let its smoke out. Heed the warning from the fire gods, fix the short, or their return trip may be not be as benevolent. LOL

_________________
67' Dart GT Convertible; the old Chrysler Corp.
82' LeBaron Convertible; the new Chrysler Corp
07' 300 C AWD; Now by Fiat, the old new Chrysler LLC

I read that last night lol, about fixing the problem or it would just happen again lol.

As I understood, if it melts, it would melt in the black casing though, and I'm not sure that was the case here.

Here is a picture of a different link on the same pyramid thing, we found the break in the wire between the black casing and the pyramid thing. You can also see the broken wire in this picture.


Is that the melt zone?
Does anyone know what this circuit is? Like I said I have been searching for a drawing for a LONG TIME and can't find one.

Thanks for all the help, my brother and I are pretty much electrical virgins lmao

_________________
1981 B-150 with an unknown year /6

Are you using a factory wiring diagram? As you can see in the 1983 van wiring diagrams I have posted below, fusible lnks are identified by a little square around the wire with "FUSIBLE LINK" written in the square.

_________________
Casually looking for a Clifford hyperpak intake for cheap.

I been looking everywhere for these lol

When I was young and dumber I blew a hole in #5 running with no oil lol.

We bought a replacement van that my dad swears was an 81 for the motor and other goodies, but now I'm thinking it wasn't.

None of my diagrams for 81 showed a computer, just ballast resister ignition.

What really confused me is auto zone sells a computer for an 81, but that was the only info I could find about an 81 spark control computer.

Thanks for the diagrams!

Like I said, we've never looked into electrical conditions before, so coil, cap, rotor, plugs and wires and still no spark made us start unwrapping the wires lol.

Never saw a fusable link before either

_________________
1981 B-150 with an unknown year /6

To be clear, the diagram I posted is for a 1983 van with a spark control computer and no 02 feedback. The diagrams I posted were for exemplar purposes only. These diagrams are probably about 90% correct for your 1981 van, but I strongly encourage you to go purchase a factory service manual for your specific van and use the wiring diagrams contained in it. There are readily available on eBay for very reasonable prices.

_________________
Casually looking for a Clifford hyperpak intake for cheap.

Good thinking, just picked one up!

According to the diagram you posted, all the way to the right, and 4 down on the bulkhead is a wire for the wiper motor, not attached to a fusible link, so that may not be right lol

I still dunno if 81's came with a computer, as the Haynes manual I have for it doesn't say anything about a computer.

_________________
1981 B-150 with an unknown year /6

Haynes manuals are best used as a doorstop or a footstool. It is possible that a 1981 Dodge van came with a computer, but not likely.

There are several fusible links in the wiring system. The best way to tell which link is blown is to see what electrical accessories don't work and then trace backwards from there.

_________________
Casually looking for a Clifford hyperpak intake for cheap.

Back to melting fusible links:

A fusible link can fail in one short section or the whole length can fry. I suspect it depends on how good the electrical connection, or how well a short makes its connection to ground. A direct grounding of a conductor to a good clean ground will flow a lot of amps in a second or two making a link glow and conductor like a bulb causing a great smoke show. A short to an oxidized, or semi non conducting ground point will act like a normal load passing a small flow of amps slowly heating up a link which may burn braking the circuit or it may take several cycles of the short making and braking before melting the link.

One needs to carefully inspect all conductors and electrical devices downstream from a compromised fusible link looking for broken insulation, or defective devices with an internal short. Don’t just tape up a compromised conductor, remove it, and replace with fresh conductor of same gage and color, and install fresh connectors. This electrical repair can take a bit of time to complete, but if you take your time, follow a copy of the diagram Reed submitted marking off each conductor as you proceed; the repair and van will be electrically reliable for a long time.

_________________
67' Dart GT Convertible; the old Chrysler Corp.
82' LeBaron Convertible; the new Chrysler Corp
07' 300 C AWD; Now by Fiat, the old new Chrysler LLC

We picked up a few of those 4 into one multiplexer things at the junk yard.

Hoping to just splice them into line.

At least until I can see an actual schematic.

The one above doesn't show it.

I just dunno if it's 2 hot in, 2 hot out and the back side is ground or if it's four in, one out the backside.

I really don't think it burned, I think it just wore out.

_________________
1981 B-150 with an unknown year /6

I think wjajr is giving you good advice. Since you just got the vehicle, the best bet is to learn as much as you can about the electrical system, and systematically go through it replacing the brittle wires and worn out stuff. Once you become an expert on this car, you can apply what you learn to other vehicles, and have less of a learning curve. All the early mopars have some basic wiring in common. Also you can really improve things like lighting and ignition with some simple upgrades.

_________________
/6 '67 Barracuda convertible, electronic ignition, 4-OD, street cam, SBP KH discs, 3.55 SG 7.25" 1" t-bars. Bilstein.
340 '67 fastback, Doug Nash 5-speed.
1988 Toyota pickup work truck