fussing and fighting with electrical after fusible link replacement

[swelltimes]

I recall contributing to this endeavor early on, but a lot has been suggested and tried thus far.

I’ve reread thru this thread, but would like to fully understand the current symptoms.

In post #29, you said, "I have tried jumping the new fusible link from the battery to the harness, to the extent that I reinstalled the original piece of wiring that I removed: the same symptoms of non-starting persisted.".

What does this mean? If you jump over the fusible link, do you see the same result as you do with the fusible link in play? e.g. "Nothing", or does the starter click? Do the headlights work? You mentioned a "sad, weak" horn somewhere.

In post #36, you said, "When I was testing, I left the ignition key on while I was checking voltages, and the + battery terminal was getting hot pretty quickly: is this normal?".

Battery terminals should NOT get hot... that may indicate a short or bad grounds and you could be in danger of melting your harness.

In post #36, you cleaned terminals, etc. and it started working... Now it doesn't work, again.

I still feel you have a problem in your fusible link circuit (poor connections), from battery+ to PS fender apron harness.

But, I'm also concerned, due to battery terminals getting hot, that you have a short somewhere.

The fact that, it was working briefly and now isn't working seems to reinforce the idea of bad connections... any bouncing may cause a disconnect.

A lot about the wiring is fairly straightforward, but if one is not careful, it's easy to destroy your harness and other electrical components.

The large white and white/blue wires play in the alternator-battery-ammeter curcuits...

If you remove your gauge cluster without disconnecting the battery, you chance melting those wires and causing a lot of electrical damage.

If those wires are shorted, you chance more damage to your harness.

Any shorts, absent the correct fuses and a functioning fusible link, you chance burning your truck to the ground.

I'm just saying, be careful.

I know just how frustrating electric issues can be... Even a minor tweak can cause major issues and confusing results, for those of us who are not electrical experts.

Please restate your current symptoms.

New pictures, showing the battery/fusible link connections might help, as well.

Maybe if we start over, from a known position again, we can work thru this... It may require you repeating certain troubleshooting...

Edit: I would first peel back the wire wrap and tape, from the harness, where the fusible link pigtail enters the harness... To see if there is an issue with the white/blue wire, at that point.

Danny, thank for taking the time to go into detail and help me out! I should have some more time to work on this project, and update this thread, later Sunday or next week.

I've ordered some new cable to make new battery / ground cables, too, which can only help.

 

[swelltimes]

We're back in business! I made and installed new battery and ground cables, and so far, that seems to have solved the issues. Electrical is working, truck starts up fine. Used 2 gauge cables and copper lugs, with military style terminal clamps.

Thanks to you all for your help and problem solving on this issue. Now, on to tuning the carb and hopefully getting the truck back on the road.

 

[rstoddard]

Last week, I realized that I didn't have a proper fusible link installed on my 6/77 FJ-40. I ordered up a replacement from @Coolerman, and installed it yesterday.

The starter engaged for a fraction of a second when I turned the ignition on, then all electrical went dead: no lights, no starter motor, nothing. Checked connections, still nothing.

This morning, I disconnected the new link, and jumped from the + terminal to the harness (which was essentially what the PO had done), and still nothing.

I'm getting 12+ volts at the battery, and all the way through the new fusible link, into the harness. For installation of the new part, I cleaned the battery post and terminal; stripped a new section of the white wire going into the harness; used the supplied connector to attach the link to the harness; used some dielectric grease on the connection of the link to the battery terminal.

I briefly checked fuses, and they look intact.

So, looks like I've got some troubleshooting ahead of me.

I wonder if the PO put some sorted of fuse / fusible link somewhere else in the wiring harness that I popped when I installed the new part?

Anyone else have a similar experience?


1st pic is of the set-up I just replaced.
View attachment 1710725

2nd pic is of the connector that was being used:
View attachment 1710724

3rd pic shows similar set up on - terminal (which I left alone): View attachment 1710722

4th pic shows how I terminated the + lead from battery terminal before installing new link:
View attachment 1710726
5th shows new link installed:


View attachment 1710727

5th shows new link installed:

Sir, where did you get your Fusible Link from? That's a beauty!

 

[rstoddard]

Ah ha!... that is a Coolerman Link, correct? I'm trying to get one!

 

[Solace in Solitude]

@rstoddard

‘71-‘78 KIT is 2nd item on this page

Or, if you need individual components, they are on the same page.

Or, paging @Coolerman

 

[rstoddard]

@rstoddard

‘71-‘78 KIT is 2nd item on this page

Or, if you need individual components, they are on the same page.

Or, paging @Coolerman

Thanks Danny.. I've already sent an email to Mark... just waiting to get an Invoice to place the Order!

 

[swelltimes]

Thanks Danny.. I've already sent an email to Mark... just waiting to get an Invoice to place the Order!

Spot on. @Coolerman makes great products!