Fusible Links

[Matthew S.]

I'm having an issue with a fusible link that I'm hoping someone can provide some help with. I have a 72 LT-1 and the fusible link at the horn relay has blown 3 times now. It always blows when I'm driving and causes teh entire car to die. There is nothing significant running at the time (i.e. I don;t have the AC on or the heater or headlights, etc). I'm just driving the car. I checked the wiring diagram for the front harness and other than the headlights it looks like the only other major component on the harness is the alternator. Is it possible that a problem with the alternator could be causing this link to blow? Is there anything else that might cause this? Is there a way to check the alternator? I don't want to replace the harness until I've ruled out all other possible causes.

Thanks for any help or suggestions.

[Jim T.]

Re: Fusible Links

Matthew with the fusible link blown and in charging the battery will your 72 LT-1 start and run?
Once my 70's alternator quit charging on a road trip and I installed a rebuilt alternator that on initial start up pegged the guage indicating to much output. Only lasted a few seconds until the fusible link failed. Having point type ignition I was able to get home since my battery was charged up enough and supplied all I needed to drive the car actually many miles without the alternator charging. Repaired my alternator, returned the failed newly purchased rebuilt alternator, and replaced the fusible link. This was about 30 years ago and its still running.
A good alternator repair shop can check out your alternator.

[Terry M.]

Re: Fusible Links

I'm having an issue with a fusible link that I'm hoping someone can provide some help with. I have a 72 LT-1 and the fusible link at the horn relay has blown 3 times now. It always blows when I'm driving and causes teh entire car to die. There is nothing significant running at the time (i.e. I don;t have the AC on or the heater or headlights, etc). I'm just driving the car. I checked the wiring diagram for the front harness and other than the headlights it looks like the only other major component on the harness is the alternator. Is it possible that a problem with the alternator could be causing this link to blow? Is there anything else that might cause this? Is there a way to check the alternator? I don't want to replace the harness until I've ruled out all other possible causes.

Thanks for any help or suggestions.

Fusable links operate just like fuses, except they are a lot more difficult to change. Something is shorting the 12 volts from that fuse link.

How is your alternator clocked? If not clocked properly the output terminal of the alternator can contact the rocker arm cover.

Examine the wiring harness carefully to see if something has rubbed through and may be making intermittent contact with one of the wires in the harness.

[Matthew S.]

Re: Fusible Links

Jim - when this link blows the only thing that works in the car is the horn. Everything else is dead, no starter, no headlights, no radio, nothing. The first time I replaced the fusible link it lasted for over a year. These last 2 times it has barely lasted a week so something's going on for sure.

Terry - I will check the alternator. It is clocked one position to the right but I don't think any of the wires are hitting the valve covers but I'll check it.

Thanks for the comments guys