fuse block mods

[70MTroadster]

Well, Just returned from a weekend trip in the 70 1600 and the darned bugaboo of the turn signals, dash lights and such reared its ugly head again. So.........I want to wire around that pesky fuse in the fuse block as others have done on this site. How do I do it? My 70 has 8 fuses and it is the 2nd one up from the bottom on the right side. It even gets hotter than h--- when the lights are on

Just to crow about this car........I've put over 2000 miles on it and just changed the oil and it was almost as clean as the day I put it in. The little R motor purs along at 4000 rpm in 5th at 80-85 mph with no worries. I'm beginning to wonder if I "should" stoke this engine, it just runs so darned good. Heck, I will anyway.....gotta have more power

Scott

[S Allen]

Scott.

Not speaking from experieince since I do not own a high windshield car but.... I have seen some that just put an inline fuse in by-passing the fuse block altogether. It looked pretty simple and just put the same rated amp as the stock one and you should be okay. Sounds like you are having fun with the roadster. I have been too darned busy except to beat a fender up a couple of weeks ago. Heck of a ding I got from something on the road.

Steve

[Dave]

Scott,

I had a similar problem with the fuse on my 68. The fuse block is a single row of fuses instead of double like yours. Same concept though. On mine, ALL of the lighting runs through one fuse. When the lights were on that fuse would heat up so hot you would swear it was going to melt. The wires going to and from it were starting to discolor too. Of course, with all that energy going to heat instead of to the bulbs, the headlights were dim. Probably the easiest thing for you to do is to mark all your wires (or just snap a digital photo) and remove the fuse block. Clean up all the contacts really well with a wire brush. Everything that's metal should be brushed clean. See if that solves it. If not, there's no harm in bypassing the fuse and wiring in an inline fuse of the same amperage rating.

If you really want to cure the poorly designed fuse block problem, you can throw the whole thing in the trash and install an aftermarket fuse block with the new blade style fuses. I went this route and am quite happy with it. I actually installed two separate fuse blocks. On that is powered up all the time, the other is powered only when the ignition is on. That way I can be sure I never accidentally leave my lights on!

[Minh]

I got a maybe better solution or alternate question....

Has anyone tried converting that old fuse block to a modern fuse block?

[70MTroadster]

OK guys,

I'll snap a digital photo, then clean heck out of the metal, try that, then if that does not do it, the new blade fuse block(s) sound like a plan.

I'll keep the forum posted of my progress.

Scott

[oilleak]

The earlier single row fuse boxes are notorious for melting but the later two row fuse blocks are not. I've never had an issue with mine. Same block is used in the 240Z and again, no problems. I'd start with a thorough cleaning of the block and it's connectors both front and rear. corrosion on the fuse clips/connections will cause excessive resistance. I'd also take a look for any creative wiring done by a PO. The symptom you're describing indicates that something is wrong on that circuit.

[DatsunBucky]

I'd like to just add a little something to the good advice already posted here. I was chasing a dim bulb (not me, in the driving light!) and decided that no matter what, I was going to track it down. Using a volt-ohmeter, I finally discovered the culprit was the rivet in the bulb holder that connects the wiring to the metal piece that actually contacts the bulb.

I had to take a punch and flatten the rivet a bit to get a good connection. If the metal on the fuse block looks good or cleans up OK, you might want to check any rivets or other connections other than the blades holding the fuse.

[Sloloco]

Has anyone here wired an all new fuse block into their car? Did you use Painless Performance or what? After seeing the nest under my dash I'm ready to do it from scratch (ROP electronics helps w/ my confidence!).

[Dave]

Yes, I actually put in two. One powered all the time, the other powered when the key is on. Gave me 12 separate fused circuits. See my post above.

I used the Painless Wiring kit on my Mazda Rotary Pickup. It's a bit on the expensive side but if you are unsure about wiring, it's the kit for you. They do a great job holding your hand through what can be a daunting process. Everything is straight forward and very well thought out.

[Sloloco]

I am confident enough with my electrical knowledge to not need the help so should I just use an old harness from the junk yard? I was thinking maybe late model GMC as they seem easy to wire.

[Dave]

Now you have me confused!

Did you mean to say you want to get an old fuse block from the junkyard? Not an old harness. Correct?

Generic fuse blocks are so inexpensive, I would just go buy a brand new one from your local autoparts store. I think mine were $8 each. You should be able to find several styles to choose from depending on how complicated you want to make your life.

I chose a style that has one common power lead going into the fuse block and branches off to multiple fused circuits. By doing this, I was able to quickly eliminate 1/2 of the OEM wires going into my fuse block. I ran one fat wire between the fuse block and the battery with a fusible link in between. This way, I have a bullet proof supply of power to the fuse block and to each feature on the vehicle.

If this is too adventurous for you, I'm sure you can find a generic fuse block at the autoparts store that mimics the function of your OEM one: Multiple power inputs leading to fuses with outputs to each feature on the vehicle. That should be just about exactly a plug and play swap!

[Guest]

Well, I was looking to do that but was also thinking of doing over the wiring for the ingnition,gauges and lights. It sounds like a lot but after redoing a complete harness from engine to air bag on a Mustang this should be cake!

[TR]

Hey guys,

If you have heat like that anywhere in the harness or fuse block, it is time to install a relay. Putting just the headlights on the relay would probably cure the problem altogether. Splitting the loading through multiple fuses should be considered a band aid solution...

Relays are cheap, work great and very easy to install. Way easier than a fuse block...TR

[70MTroadster]

Well TR,

Looks like my idea for improved lighting and this fuse block problem I am having have met up with each other.

Ready to send me a wiring diagram for how to install the relays for the existing lights so my heating problem will go away.? Sure would be nice

As I've stated before I am dumb as dirt when it comes to wiring and electrics......but.......the fuse that is heating up is the one marked Park-Tail and not one of the headlight fuses.

I used a small wire brush and a cratex bullet shaped polishing dremel to clean the contacts for the fuses.

Have not tried it out yet.

scott

[TR]

That is odd! I wonder why the load on the park/tail circuit is so high? If there is not a short and just the load from the tailights is causing the fuse box to get hot...That might be best solved by splitting the load (as I previously said was the wrong way to go!)...That sure points to something wrong, though, as the load from the tailights is not that high...

Send me your email address and I will send a basic diagram for the headlight relay setup...TR