Yeah, I think that one of these days I am going to put a relay in for the running lights too. I've been through two headlight switches in 80,000 miles and the previous owner replaced it at least once. Like I said, my truck has had higher than average use on rough roads, so that may be a factor. I do want to move towards replacable fuses, though. I just don't see why they wouldn't work. I'm guessing the FLs came along for cost reasons, not because they were better. I mean, if the dang thing blows out out in the boonies at night sometime, only because it had too much vibration adn the running lights were on, I sure would rather pop a new fuse in and be on my way than be trying to splice a new piece of FL onto the ever-shortening wiring harness in the rain and mud on the side of the road somewhere.

ya know?

 

WR,

I couldn't agree with you more. Roadside wiring repairs are zero on the fun scale. I believe your headlight switches are failing due to high amperage loads running through them. They don't appear to have been designed to flow the higher amperages when you add additional loads to them and the internal contacts overheat and fail.

Thanks for the map lesson on Skamokawa. How do you properly pronouce the name?

 

Ska-MOCK-away

Yeah, I have a custom steel flatbed with running lights all around and running lights on top of the cab, and that plus the trailer lights eventually kills the HL switch.

You got any ideas about the amperage ratings of the different gauges of FL?

 

WR,

Thanks for the lesson, I would have been way off...

Not sure on the amperage ratings for FL, but I believe the length of the FL as well as the gauge determines the current flow capacity. That's why it is critical to replace them with equal length links to ensure proper circuit protection.

 

I'm lucky to not have experienced the fuseable link problem but I have been running relays for the headlight (low and high beams) for many years. I also ran a 10ga ground off the battery to a distribution bar and ran new grounds to everywhere.

I also run my trans cooler fan, running lights and camper lights all off switches and relays and all grounds are terminated at the grounding bar. Believe me, bad grounds are the cause of most problems in older trucks. I also once or twice a year clean and grease most of the so called water tight connections that are around.

Poor battery cable connections are a big source of problems also. Four or five years ago I read an article some where on the internet about battery maintenance. I had battery problems until I applied RTV around each post and then put the felt pads and then put the cleaned cables back on. The RTV keeps the acid fumes from comming up around the posts. Above all check the water one a month in these batterys, no battery is maintenance free if it is lead acid.

Just my 2 cents worth.

Jim

 

Don't get me wrong I didn't mean anyone was bashing but just that these trucks are getting pretty old for normal pickup trucks. I run relays on all my running lights, trailer lights, fog and driving lights so I guess that is why I have had no problems with burn't fuse links. When we add things that were not on the truck from the factory we need to add the proper relays and fuses to protect the wiring. When we don't we get breakdowns and burned wiring or fuse links. Just like when bombing the trucks we can't blame the truck when something fails or breaks if we don't take into account all the safety issues and fail safes that we should. I guess what I am saying is don't blame the truck or manufacturer if we cause the problems.

 

rlyons,

I agree completely. One needs to upgrade the system if you are going to place additional loads on the circuits. The best way to do this is often with the use of relays. Some form of circuit protection is mandatory as well, ergo the fuses. Jim had a good point about using a common ground distribution block. The terminal blocks can also work well for creating a place to tap into 12V for additional power. Much cleaner and safer than scotchlocks or wire nuts and a rat's nest of wiring. I've seen some real butchery when it comes to wiring over the years....

 

I forgot to add earlier that my fusible link failure didn't actually roast when it failed. I believe it built up resistance over the years and then increasingly became warmer under load until the wiring eventually became brittle and failed.
I was having trouble with power loss at start-up and noticed that if I moved the fusible link block, my power would come and go.
I don't have any additional add-ons on my truck, either.

 

Yeah mine looked like they had failed slowly as well. I had to keep clipping off bits looking for a section that wasn't brittle to splice to.

And I wasn't so much blaming the manufacturer for causing the FL to fail, I was blaming them for being too cheap to make it easily fixable, and too ??? for not carrying the specially shaped part that is designed to fail.

 

After one of the wires burnt up and damaged the other wires bolted to the battery, I got a 5-connector terminal from a 80's Chevy truck from the pickapart for 5 bucks. It had fusible links on them. I wired the Dodge to this terminal. From the terminal was a large wire to the battery. So far no problems.

 

Here's a link to the Wiki entry for American Wire Gauge. BAsically you need to use circuit breakers or fuses of the no larger than the smallest wire which the fuse/breaker protects, unless there is another fuse/breaker downline which protects the wire.

http://en.wikipedia.org/wiki/American_wire_gauge

If you have a #10 AWG wire then you fuse it for 30 amps if that circuit has a branch with a #16 AWG then that branch circuits also needs a 10 amp fuse as close to the branch of the #10 wire as possible.

I know of no reason whatsoever not to use fuses or better yet circuit breakers in place of fuseable links.

 

dont be too hard on the engineers... They have to listen to management telling them it has to be so cheap that it is practically free. And they have to listen to the safety guys telling them it has to be completely monkey proof.

If the trucks had nice additions under the hood like circuit breakers and service loops in the wiring, then the price of the truck would creep up and most people would buy the competition cause they dont know what most of those features are.

Hot rodders, and custom car builders typically use a Maxi fuse in place of fusibile links. Maxi fuses look like the standard blade fuses but just 4x the size. They are popular in the fuse panels of newer cars. The trick is finding an inline holder for maxi fuses, Most hot rod wiring shops have them. These work great and are replaceable.

If your shorten a fusible link, the trip current goes up.

If you need extra length in the harness, add some wire.

Replacement fusible links are available in the cheapo generic parts rack at your local autoparts store.

Fusible links may be the only way to make the safety guys happy with a design. Circuit breakers and fuse holders have to have a pigtal to the battery. that pigtail can still catch on fire if shorted. Fusible link designs can eliminate the pigtail to fuse.