FJ62 Voltage Drops + Fusible Link Heat (1 Viewer)

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Feb 22, 2019
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Buffalo, NY
Novice mechanic and even more unfamiliar with automotive electrical. Any confirmation/contradictions on my hunches would be appreciated!

This is for an 88 fj62

My voltage drops anywhere from 1-2 volts while idle. However it returns to normal once accelerating/moving. Turning lights on, etc. gives a visual drop in voltage. Got the battery tested and although it is almost 4 years old it was fully charged when I took it to Autozone.

Based on this info I don not think it is the alternator or battery. However, the fusible link gets very hot after driving 15-20+ min. (although I have no idea how hot it usually gets or if it should get hot at all, i think hot electrical parts are not normal?) I have a feeling that there is a lot of draw an a probably oem fusible link which is causing these voltage drops? I'm sure I could be way off, but that seems like the logical first step.
 

MTB Land Cruise

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Jun 18, 2020
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Novice mechanic and even more unfamiliar with automotive electrical. Any confirmation/contradictions on my hunches would be appreciated!

This is for an 88 fj62

My voltage drops anywhere from 1-2 volts while idle. However it returns to normal once accelerating/moving. Turning lights on, etc. gives a visual drop in voltage. Got the battery tested and although it is almost 4 years old it was fully charged when I took it to Autozone.

Based on this info I don not think it is the alternator or battery. However, the fusible link gets very hot after driving 15-20+ min. (although I have no idea how hot it usually gets or if it should get hot at all, i think hot electrical parts are not normal?) I have a feeling that there is a lot of draw an a probably oem fusible link which is causing these voltage drops? I'm sure I could be way off, but that seems like the logical first step.
Had the same problem for years. During this summer I replaced all the battery cables with heavy duty cables. Problem was solved. My LC is an 89. Search heavy duty battery cables on this site and you will a couple of MUD vendors who sell a complete set. Good Stuff....
 
Joined
Feb 22, 2019
Messages
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Buffalo, NY
Had the same problem for years. During this summer I replaced all the battery cables with heavy duty cables. Problem was solved. My LC is an 89. Search heavy duty battery cables on this site and you will a couple of MUD vendors who sell a complete set. Good Stuff....

Thanks! I'll look into it. I'm not sure if my existing cables are oem or not. The voltage drops are recent, they started maybe a month or two ago, bot sure if that plays a role. Should I be worried about the excessive heat from the fusible link? (fire/stop working altogether?)
 

MTB Land Cruise

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Thanks! I'll look into it. I'm not sure if my existing cables are oem or not. The voltage drops are recent, they started maybe a month or two ago, bot sure if that plays a role. Should I be worried about the excessive heat from the fusible link? (fire/stop working altogether?)
Not sure how you define excessive heat... but the purpose of the link is to burn off to prevent a short to the electronics. It requires a visual inspection to see if any have burned/broken off.
 
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Not sure how you define excessive heat... but the purpose of the link is to burn off to prevent a short to the electronics. It requires a visual inspection to see if any have burned/broken off.

Well, I'm not sure how much heat it should be giving off. It sounds like heat coming off of the fusible link is normal? I wasn't really sure what it did to be honest haha! Those cables kits are nice! I think I'll have to spring for one!
 
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Just an FYI. Your alternator probably doesn’t produce it’s rated amperage at idle. Better battery cables. More grounds new wiring etc will all help. But a voltage drop at idle is to be expected. While you might get 14v at idle you don’t have the full amperage to back it up.
 
Joined
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Buffalo, NY
Yeah, that all makes sense. What threw me the most was that I've had my 62 for almost 2 years and its a relatively recent issue. I should probably redo all of the electrical sooner rather than later.
 

OSS

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The fusible link is a junky thing held together with lame spade connectors, Your connectors inside the plastic housing are corroded which increases resistance, which creates heat - which you discovered. Eventually the heat will start burning the plastic housing which will deposit more carbon on the connector which will make the electrical connections of the junky spade connector worse which will increaseresistsncewhichwillcreatemoreheat... etc

Take apart the FL and behold its destruction in the making
 

John Staton

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I hear about folks having to replace their fusible link on occasion. I am wondering is anyone makes a good aftermarket FL. Sounds like it would not be a bad thing to have an extra on hand.
 
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Vancouver, BC
Just about any auto parts store has fusible link wire, both in lengths or with connectors pre crimped. Just get the gauge you need For your application. It’s just another type of fuse...
 

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