duster star
Member
I have a 73 duster there is a main fuse connection at the fire wall above the brake reservoir with a 25 fuse. It keeps bowing at different times when I start any ideas what would cause this and where to start to fix thanks
main fuse
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There shouldn't be a "fuse". It should be fusible link. They both do basically the same job of circuit protection. Someone before you had issues and didn't fix the problem. You have an excessive current draw, some bad connections, or weak grounds somewhere and it could be anywhere under the dash.
Woodys_Cuda
Ontario, Canada
I agree with Mike above. It should be a fusible link. Trace the wire, it should be a battery feed. Other common usual areas to check are the bulkhead connector at the firewall for corrosion or burnt wires. If you have an ammeter connected it is another cause of problems. You should find the wiring diagram for your car to trace and test.
What he said. Or just wait for the smoke and fire to appear.
Keep a couple or Three extinguishers with you if you drive it.
Woodys_Cuda
Ontario, Canada
Here, found a thread that will help you. You can also find more info using the search function
Bulkhead connector
User @Mattax knows a lot more than I do. He would be my go to guy.
Bulkhead connector
User @Mattax knows a lot more than I do. He would be my go to guy.
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duster star
Member
Thanks for the help. it is a fuse able link it looks like 12 Gauge wire would a 25 fuse be right. i had put a new alternator in. I think i will start looking every where else before under the dash it's a rat's nest
Sorry I'm headed out soon. Although ironicly my FABO doesn't crash my laptop so when I have internet service I can check in after work sometimes.
If its a 12 gage fusible link originally then its an optional heavy duty wiring. This was most common on a-bodies with rear window defrost grids. Do a search for rear window defrost wiring.
Normally its a 16 gage link to protect the 12 gage wires. The advantage of the link was it doesn't melt with a spike or even a few seconds of high current.
They can also fail when 'abused'. In quotes because its not intentional. It can be as innocent as recharging a severely discharged battery by driving on the highway. If the ammeter is showing over 20-25 amps in or our of the battery - that's going to heat connections and wires up. Which ones fail (melt first) under those situations will vary.
But if the link melted quick, then its probably a dead short. If its after the ammeter, you may have had a chance to see the needle go full discharge (40 amps+) before the link melted.
At a minimum use an ohmmeter to check for dead shorts before reconnecting the link.
The '73 wiring diagrams are a little complicated. I've posted simplified versions just showing the main circuits for both the standard and the heavy duty wiring. Those should help you.
If you think the problem is still there, rig a test lamp in-line. Don't try to start the car or anything. Just use that to show if there is a ground so you don't go through a bunch of links while hunting the short.
If its a 12 gage fusible link originally then its an optional heavy duty wiring. This was most common on a-bodies with rear window defrost grids. Do a search for rear window defrost wiring.
Normally its a 16 gage link to protect the 12 gage wires. The advantage of the link was it doesn't melt with a spike or even a few seconds of high current.
They can also fail when 'abused'. In quotes because its not intentional. It can be as innocent as recharging a severely discharged battery by driving on the highway. If the ammeter is showing over 20-25 amps in or our of the battery - that's going to heat connections and wires up. Which ones fail (melt first) under those situations will vary.
But if the link melted quick, then its probably a dead short. If its after the ammeter, you may have had a chance to see the needle go full discharge (40 amps+) before the link melted.
At a minimum use an ohmmeter to check for dead shorts before reconnecting the link.
The '73 wiring diagrams are a little complicated. I've posted simplified versions just showing the main circuits for both the standard and the heavy duty wiring. Those should help you.
If you think the problem is still there, rig a test lamp in-line. Don't try to start the car or anything. Just use that to show if there is a ground so you don't go through a bunch of links while hunting the short.
Here you go
Standard wiring.
And this thread has a couple of posts (one by me one by 67Dart273) that explain it.
www.forabodiesonly.com
Aother example of troubleshooting
www.forabodiesonly.com
Standard wiring.
And this thread has a couple of posts (one by me one by 67Dart273) that explain it.
1973 Duster Electrical Issue
I have a 73 Duster 340 that I completely rebuilt. It is all numbers matching. I kept the original wiring harness. The car starts, run, and drives. I don't have anything electric except for the front running lights. I have the left side marker light and the left fender top turn signal. I do have...
www.forabodiesonly.com
Aother example of troubleshooting
Burnt some Spaghetti!
Hi Folks, I am venturing down the Rabbit hole of wiring at the moment and noticed two fried wires on my bulkhead connection. One is coupled with a black wire, I think it was originally white? The other one is green. 1. Just wondering what might have caused this so I can check and hopefully...
www.forabodiesonly.com
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