80 died on the fwy! (1 Viewer)

[SFSurfer]

Hey folks - Heading home from a weekend trip with the fam, my 97 80 died on the fwy, engine shut off, loss brakes, power steering, the whole nine yards! Not so fun, but luckily was able to coast to an off-ramp and pull the e brake to stop. It looks like the relay for the EFI blew and with it, fried part of the fuse box. I tried replacing the fuse but didn’t have any luck getting it started. Has anyone else experienced this with their 80?

 

[jonheld]

It looks like you're going to have to replace that terminal in the fuse box.
Part # 82998-12140
Comes with 6" of pigtail so you can splice it in.

 

[SFSurfer]

It looks like you're going to have to replace that terminal in the fuse box.
Part # 82998-12140
Comes with 6" of pigtail so you can splice it in.

Awesome, thank you for the info. Much appreciated.

 

[bpenn1980]

No other electrical issues in the past? Was the fuse rated appropriately? Hopefully someone will have an idea what happened.

 

[SFSurfer]

No other electrical issues in the past? Was the fuse rated appropriately? Hopefully someone will have an idea what happened.

I’ve had zero issues in the 4 plus years owning it. Then it was just poof, lights went out literally on the freeway. Looking at the fuse on how it fried, it seems like it may not have been sized properly or something fuel pump, something failed and fried the fuse along with the terminal?? It’s beyond my level of expertise!

 

[CJF]

No other electrical issues in the past? Was the fuse rated appropriately? Hopefully someone will have an idea what happened.

Blue is 15amps. Anyone know offhand whether that's what's supposed to be in there?

 

[bski90]

15 is correct for the ECU

 

[jonheld]

No other electrical issues in the past? Was the fuse rated appropriately? Hopefully someone will have an idea what happened.

More than likely just a poor connection.

 

[Kernal]

Not my area of expertise, where is the likely short located for that circuit?

Trivia: In the top photo when magnified you can see a light blue (far right) 15 amp fuse that appears cracked and maybe swollen. The darker blue 15 amp next to it appears to be a different brand, no ridges around the top edge.

Is the popped fuse OEM, the others?? Hard to tell from the photos.

 

[bpenn1980]

More than likely just a poor connection.

Hi Jon,

The fuse itself had poor connection at its contact points? So it was arcing (maybe wrong term) and generating heat?

Makes me want to replace all my blade fuses and make sure they are seated fully!

 

[SFSurfer]

So the mystery was solved via a big thanks to Gary and crew at Mudrak for helping me out. Turns out the O2 sensor wires came in contact with the exhaust, burning / melting the wires, blowing the fuse, thus leaving me coasting down the freeway. Hopefully this doesn’t happen to anyone else! Thank you for all the help and advise. I think I aged 10 years being stuck on the side of a freeway with a 6 and 8 year old. The topper was my 6 year old decided she really needed to take a poop as well while we were stuck. Good times!!

 

[gummycarbs]

Turns out the O2 sensor wires came in contact with the exhaust, burning / melting the wires, blowing the fuse

That's definitely happened before on here, but I've never heard of a blown fuse leading to melting the fuse holder! Makes me question if it was a poorly made fuse that didn't blow when it should have.

The only time I've ever seen fuse holders melt like that is when an oversized fuse was used, or was bypassed with wire or something. I guess it's possible that the fuse tab was barely contacting the socket, but *how*? Sure looks to me like witness marks from the socket making contact.

 

[SFSurfer]

That's definitely happened before on here, but I've never heard of a blown fuse leading to melting the fuse holder! Makes me question if it was a poorly made fuse that didn't blow when it should have.

The only time I've ever seen fuse holders melt like that is when an oversized fuse was used, or was bypassed with wire or something. I guess it's possible that the fuse tab was barely contacting the socket, but *how*? Sure looks to me like witness marks from the socket making contact.

My thinking is since the O2 sensor wires came in contact with the exhaust, the fuse essentially was burned not from over current, but rather just from the wires heating up from contacting the exhaust. Just a guess??

 

[jonheld]

My thinking is since the O2 sensor wires came in contact with the exhaust, the fuse essentially was burned not from over current, but rather just from the wires heating up from contacting the exhaust.

No. That's not how things work. The burn marks on the fuse blade was caused by arcing.

 

[Rifleman]

No. That's not how things work. The burn marks on the fuse blade was caused by arcing.

Or resistance causing a heat build up from corrosion between the male fuse blade and the female spade/wire in the fuse box. Correct me if i am wrong, but i seen to remember there have been more than a few members who have had problems with corrosion in the wires, and on some of the connectors in their engine compartment fuse box.

 

[jonheld]

Or resistance causing a heat build up from corrosion between the male fuse blade and the female spade/wire in the fuse box. Correct me if i am wrong, but i seen to remember there have been more than a few members who have had problems with corrosion in the wires, and on some of the connectors in their engine compartment fuse box.

Exactly my point. Poor contact would have caused arcing. The arcing would have developed intense heat very quickly as it tried to weld itself together.

 

[SFSurfer]

No. That's not how things work. The burn marks on the fuse blade was caused by arcing.

That makes sense. When I opened the fuse box the burning smell was definitely noticeable.

 

[dpeshkin]

Glad

That makes sense. When I opened the fuse box the burning smell was definitely noticeable.

Glad you got it fixed. Hope you can make it to OB.

 

[gummycarbs]

This morning it occurred to me that, yeah, it has to have been a poor connection, since only one side of the fuse was affected. Excess current should cause damage to both sides.

I think I'm going to spray DeOxit on all my fuse box contacts...

 

[AndrewInf]

My old 240Z had a severely melted fuse box when I bought it. The copper parts were riveted together and the contact at the rivets slowly got compromised over decades by oxidation, so even though the current never reached the level required to pop the fuses, the current bottlenecked through the shrinking conductive contact points made it too hot and melted the plastic body of the fuse box. I found an original but un-melted fuse box and modified the wiring of the car to include relays and in-line fuses for the parking lights and head lights (the big current draw items through that box) and run smaller fuses on those circuits. Basically displaced the load out of the fuse box. My Z was around 30 years old when I got it and had these problems for some time prior; many 80 series LCs are getting to that age, so wouldn't surprise me if you had a similar issue.