Fuse problems . . .

[New-to-240z]

So, I am having some problems with my turn signal fuse. It seems it somehow blew out and is now blowing out fuses all the time. It actually melted off the original fuse holder and is being a PIA to fix. I was thinking of just pulling the wires out and putting in a panel mounted

Here's the breaker I'm thinking of wiring it to . .

Link to page

Do you think this would resolve the problem?

[zKars]

Fuses blow due to a current load in excess of the fuse rating. This is a problem with a something on the circuit drawing more current than it should, like a short circuit to ground or a series of corroded connections. No fuse upgrade will solve it, you have to find the cause of the problem. The fuse is just a safety valve. This is a very common fuse to get overheated.

Start by thoroughly cleaning the fuse connection holders, then work backwards cleaning all bulb sockets on all lights that this fuse powers, and their associated connections. Bad connections = resistance = heat generation. Happy scrubbing.

[New-to-240z]

What should i use to scrub the pieces?

I know that I bought some new bulbs from ebay, and on the bottom they only have 1 dot, where as the ones they replaced had 2 dots. Could this be the problem as well?

Also, I figure it would be a good idea to replace the fuse with a breaker so as I test, I don't go through 20+ fuses :-) I could just press it back in to begin testing again. Could save me some $$ on fuses. It would also rule out the fuse connectors as the problem. Just my thinking . . . what do you think?

[SteveJ]

What should i use to scrub the pieces?

I know that I bought some new bulbs from ebay, and on the bottom they only have 1 dot, where as the ones they replaced had 2 dots. Could this be the problem as well?

That doesn't help. You're crossing circuits by doing that.

"1 dot" Type 1156 bulb

"2 dot" Type 1157 bulb aka dual filament

Don't cross the streams.

Also, I figure it would be a good idea to replace the fuse with a breaker so as I test, I don't go through 20+ fuses :-) I could just press it back in to begin testing again. Could save me some $$ on fuses. It would also rule out the fuse connectors as the problem. Just my thinking . . . what do you think?

I think you should learn to use a multimeter and check the resistance in the circuit. You could have a short in circuit. Rule that out first. If you look on my blog, I have a post about electrical troubleshooting, including a link to a video on how to use a multimeter.

[Darrel]

Corrosion + resistance = bad.

hot combo switch before putting in MSA fuse block, after installation it was only warm.

MSA fuse block, very good plug and play replacement.

To get the most out of the MSA fuse block you should go with Dave Irwin's parking light harness and headlight harness. Now the combo switch doesn't get warm at all.

[SteveJ]

Just to clarify something. It's not an increase in resistance. It's a decrease in resistance.

P=V²/R

As resistance increases, power decreases. Less power means less heat.

Corrosion at the light sockets gives the current an alternate path to the filament as the corrosion breaches the gap between positive and negative. Multiple paths means more current can flow since P=VxI.

Corrosion at the connections causes a different problem. When the interface between to electrical devices gets corroded, the path for electrons to flow gets narrowed. This causes a localized heat buildup. If it happens at a switch, it can melt the solder.

For cleaning, use something like Caig Deoxit. On rusted contact surfaces, use sandpaper of around 800 grit. You don't want the metal pitted since that reduces the contact area.

P - Power

V - Voltage

I - Current

R - Resistance

[New-to-240z]

I bought the parking light upgrade harness from MSA and cleaned off the terminals and replaced the fuse. No more problems. Everything seems to be working as it should . . . . for now. :-) I didn't have any shorts in actuality, it was just the corrosion and amount of heat. Thank you everyone for your help.

[SteveJ]

Did you check out the light sockets, too?