280Z fusible links

[HusseinHolland]

8 hours ago, Zed Head said:

It's been pretty well documented that what is shown as a red link is actually a brown link (they're shown in the FSM) and it is also a lower rating (smaller gauge) than the green link (also in the FSM).  I never looked too closely at that chart in the past but now see that it has a yellow and a pink link.  You won't find those on a Z.  Maybe a ZX but not a Z.  (Sorry Blue 246, no offense intended).  Some of the Z car aftermarket suppliers like thezstore.com have updated their fusible link pages to show it.

Don't forget that fusible links are "slow blow" fuses.  Most automotive fuses are meant to fail quickly.  Good luck.

Thanks. I'm really not concerned with the fusible link features, just the amperage. I'm going to use a Midival block , which is very much akin to the primary fuse circuit on my Volvos. I may use one of the battery mounted blocks if there is room

 

I'm used to rewiring/adding circuits. On my Fiat X1/9 I had to completely rewire for a Honda EMS, which required adding a couple ancillary fuse/relay blocks

Edited March 13, 2023 by HusseinHolland

[Zed Head]

9 hours ago, HusseinHolland said:

I'm really not concerned with the fusible link features, just the amperage.

Amperage rating (ampacity is apparently the proper word) is a feature.

 

 

[EuroDat]

A fusible link is designed to withstand an overcurrent for a short period of time before burning through where a fuse will blow very quickly at it's rating.

They say that a fusable link is rated to about 4 gauges under the wiring it is protecting.

Sizing a maxi fuse to compensate for the brief overshoot could result in a contant overload.

Manufacturers do a lot of R&D when designing the wiringloom, but there probably is some room for "error" in the gauging of the wiring loom and the systems can be unbalanced these days with all the led lighting and lower current consuming accessories we can use. You could probably go under the original fusable link rating and not have any issues.

Edited March 14, 2023 by EuroDat
Typo

[HusseinHolland]

Yes, the function of the fusible link has been wrung out over the whole thread. It is also known that the heavier rated fuse types were not in production in the early 70s. The PO of my car (owned it from new) told me he had issues with the links. Who knows what rating he was actually given, and whether it was appropriate for the '75 spec. 

I'm just going to go with the equivalent ratings (40a = green, 80a = black) based on the chart I linked. I see no reason for concern.  If I were interested in keeping the car completely original, I would source the appropriate wiring. I can appreciate that there are people to whom that matters.

Edited March 14, 2023 by HusseinHolland

[SteveJ]

Given the wire sizes in the harness, 70A (alternator) and 30A (all others) would probably be appropriate.

Blue Sea provides the fuse curves for their Maxi Fuses. https://www.bluesea.com/products/5143/MAXI_Fuse_-_80_Amp

The curve is the same for each amperage as it's based upon percent of fuse rating.

 

[HusseinHolland]

This is what someone did to 'repair' the fusible link for the EFI. 

 

 

The ground side pulled right out of the butt splice seen below. I'm adding the fuse block

New cable ends crimped for EFI feed and starter cable

Clears hood inner frame

 

 

[SteveJ]

8 hours ago, HusseinHolland said:

This is what someone did to 'repair' the fusible link for the EFI. 

 

 

The ground side pulled right out of the butt splice seen below. I'm adding the fuse block

New cable ends crimped for EFI feed and starter cable

Clears hood inner frame

 

 

I can't put my finger on it, but something about your solution appeals to me more than the one done by the IPO (idiot previous owner).

[SteveJ]

@HusseinHolland I saw this on Reddit Just Rolled Into the Shop and thought of you.

[Zed Head]

On 3/15/2023 at 6:19 PM, HusseinHolland said:

 

Clears hood inner frame

 

What brand is that fuse panel?  Looks pretty nice.   Many newer cars have similar panels mounted next to the battery like that.  Those fuses look much more robust than the typical Maxi-fuse.

Ford calls theirs a Mega Fuse.  Not sure how many sizes there are.  

https://www.oemfordpart.com/oem-parts/ford-main-fuse-f87z14526ba

 

Edited March 17, 2023 by Zed Head

[HusseinHolland]

24 minutes ago, Zed Head said:

 

What brand is that fuse panel?  Looks pretty nice.   Many newer cars have similar panels mounted next to the battery like that.  Those fuses look much more robust than the typical Maxi-fuse.

 

Its an MTA 0300839.

Connector ID is a US distributor. The cable terminals & fuses are sold separately, but listed with the main component so it's easy to figure out what you need based on the gauge wiring you are using. 

 

EDIT -  uses Midi & Mega fuses

Edited March 17, 2023 by HusseinHolland
typo on company name

[Zed Head]

Thanks.  Ford also used the older style fusible links up by the battery for quite a while.  My 2003 has a set.

Here's a link to your panel and a picture of a Ford fusible link, just for fun.  Borrowed the picture from the internet.

https://nexelec.com/MTA-0300839/

 

[SteveJ]

Also I have thought about playing around with this: https://www.amazon.com/gp/product/B00902G49U

It has four slots for fusible links and a plug that is connected to ATO fuses. It would be a matter of figuring out where to mount it to reach the battery.