AdmiralYoda

I'll try and make a long story even longer. Yesterday for the first time my 87 4Runner didn't want to start. Turn the key....1 single loud click. Try again....same thing. Battery is fine. But I've got the little wiring mess up that RAD4Runner described how to fix so well:
https://www.yotatech.com/forums/f199...l#post51975700

8.95V is whats actually getting to the starter solenoid. I plan on upgrading that today.

But in the process of troubleshooting I noticed the 40A fusible link that goes from the battery to the fuse box is knarly. My guess is that someone once upon a time connected some jumper cables backwards. It has 3 butt splice connectors and was wrapped in electrical tape. It is really loose, like one of the butt connectors is about to come apart.

What is left of the original fusible link is actually about 3" long. The whole thing needs to be replaced. I'm going to use #8AWG wire (future proof for alternator upgrade) with a 40A MAXI style fuse.

Okay....where the hell is this story going?
I can't get the inline fuse locally so its going to have to be shipped. But I need to drive the truck now and don't trust the current wire.

Since the current fusible link wire is about as bad as it gets.....would it be reasonable just to replace it with a straight wire until I get the inline fuse? Or am I just asking for trouble? I know the reasons for a fusible link but what is worse for the next week or so...one that is about to fall apart any minute? Or one that can become a tiki torch if something goes wrong?

scope103

Dorman (sold through O'Reilly and lots of places http://www.oreillyauto.com/site/c/de...0220&ppt=C0172) offers fusible links.

I used to think that a fusible link was made of something special, but I have read numerous places (e.g., http://en.wikipedia.org/wiki/Fusible_link) that it's ordinary wire just 4 wire gauge sizes smaller than what's being "protected." Meaning, you could get a piece of 14ga solid house wire, carefully install it with crimp connectors, and you'd be done. I guess the idea is that if you have a short circuit so bad that the regular fuses fail closed, the fusible link will just localize the part of the wire that melts.

AdmiralYoda

Agreed on all counts but one. I thought it had special fire retardant insulation so in the event there was a dead short the wire melted but didn't catch on fire.

I have tons of #8 wire and I'm tempted to put a straight cable in place while I wait for the inline fuse to come in.

wyoming9

iTrader: (1)

You must really live in the woods!!

All the Parts places I deal with stock the fuses .

I have made quicky holders out of female spade connectors.

I am sure all my Fusible links have been replaced years ago.

Being stuck once was all it took to replace them with fuses.

AdmiralYoda

Wyoming...believe it or not I'm smack right in the middle of civilization! I went to Autozone, Advance Auto, O'Reily, Napa, and CAP. The biggest inline fuse they had was 20A. If I'm going to do this I'd rather do it once and do it right....so I ordered a Bussmann HHX Maxi fuse holder off of Amazon and a couple Bussmann MAX-40 40A Maxi style blade fuses. The Bussmann HHX is pretty weather tight and uses #6 wire for up to a 65A fuse...just in case I upgrade other stuff down the road.

But....for an UPDATE!!! There was actually about 6" of the original fusible link left. I had some #10 wire lying around so I soldered that to the original fusible link for a temporary solution until the new inline fuse gets here.

UPDATE #2!!!!!! Thank you RAD4Runner for finding the schematic/wiring engineering mistake on the starter circuit. I ran a #8 wire from the fusible link post in the fuse box to the starter relay connector and it starts right up every time again!

Terrys87

iTrader: (1)

I did RADs starter wire upgrade and fixed my starting issues as well. Thanks Ray!!! As far as the fusible link, I believe a certain guage wire is basically all that it is and I just replace the link with that guage wire. (Currently cant recall what guage it is).

Correct way of getting to the 80 amp fuse, just incase it is needed.
All of the other fuses lift up and out. The 80 Amp you have to pry this tab to the firewall and push out the bottom.


Here it is mounted to the Fuse. It mounts behind the wires. I usually have to take a 8mm socket to the screws the first time. They can be TIGHT.

RAD4Runner

Glad to know!

Most welcome, guys. The least I could do to give back to the community that helped me find my ride and take good care of her.

Actually, upon more searching, I came across a couple of older posts that also covered same wiring mistake. One was 4Crawler's on his website.

Terry,
I believe picture above is from before you cleaned your fender ground? heh-heh.

AdmiralYoda

Here is a question. What is the point of the 40A fusible link wire going to the fuse block? It connects to the 80A plug-in fusible link. I'm not asking what does it do....but what circuits specifically does it protect?

I see that there are 3 red wires connected to the battery side of the 80A (fuse box) fusible link so the 40A (Battery-fuse box wire) helps protect the circuits related to those 3 wires.

Mostly those circuits are protected by their own fuses though. Wouldn't it make sense to connect those 3 wires to the protected side of the 80A fusible link and do away with the 40A fusible battery wire?

Many of the more modern cars are made that way...I think the Tacoma's did away with the fusible link wire as well.

Terrys87

iTrader: (1)

LOL Ray... That is an old picture. It was when I first pulled it out of the field. I did clean the ground off and also did another one of your electrical fixes that is cheap and easy to do. By cutting some of that harness above, I was able to move it forward and connect the head light ground to the battery for one less electrical issue in these trucks. No cost involved in that upgrade.

AdmiralYoda... I do not know electrical or very little. Maybe someone else can explain that. Toyotas electrical engineers were not the very best that they could of used. For as weak as I am in electricity, I have found some poor designs. Definetly room for improvement on Toyotas electrical system.