Blown Tail light fuse

[boosd]

parking and dash lights were not working, checked the fuse box 20a park light fuse was dead. Put a new fuse in, turned on tail lights, fuse immediately got hot, turned red and shortly after burned out... Put new fuse in and unhooked all parking lights, flipped the switch to parking lights and fuse still glows, so my guess is there is an issue behind the dash, or something to do with the combo switch, any ideas or thoughts to narrow this down before pulling the dash out?

Thanks

[SteveJ]

1. Examine the connector for the headlight switch. You want to look at the green/yellow wire.

2. Clean the fusebox to remove corrosion. Search this website on methods.

3. Replace incandescent bulbs for the parking lights with LED bulbs. Superbrightleds has replacements. Search on replacements for 1156 and 1157 bulbs. I did that a while back. Search for a thread called Sold on LEDs. However part numbers have changed since then.

[boosd]

Next step/Options?

btw early 1974 260z

I think it was the green/white wire and in its overheating has also melted the green/blue wire next to it....

what would i be looking for on the combo switch that would cause this? all soldering points seem okay

[EScanlon]

My suggestion is to first find and fix the problem you are having before you begin on any conversions to LED or the like.

While the LED's will use less current and may possibly work fine with your wiring as is, you're not fixing anything and it may eventually catch up with you at a very inopportune moment.

Presuming you are talking about a 240 and not one of the later vehicles, check the following:

As mentioned the Headlight Combination Switch and it's ground wire as well as cleaning the fuse box that Steve mentioned.

Dimmer Control, sometimes these will get unhooked or shorted and cause problems.

Check the individual bulb sockets on the parking lights. You may find that one or more have some corrosion in the base causing the short which is in turn blowing the fuse. Check ALL of the parking lights, not just until you find the one with corrosion.

Check the connectors to the lights. This might not change much, but the simple action of unplugging and reconnecting may decrease some of the resistance you are experiencing.

Lastly, put the year of your car in your signature, it helps others in providing help and advice.

2¢

E

[SteveJ]

Oops, my bad. It's the green/white wire. Now that you found the problem, fix it. For my car, I used a 9-pin connector from Vintage Connections. He has the parts you need, including crimpers. Unless you are skilled at crimping wires, get extra terminals. Replace the damaged wires/plug.

The problem is that the fuse is oversized for the wire gauge. The way to drop the load on the circuit to below what the wire can handle is to use LEDs. Just replacing the parking lights will drop the load to about 3 Amps or less. That will prevent the wires from melting.

[EScanlon]

Time lag error, my post above doesn't take your post into consideration. Sorry.

It looks as though you may need to open your combination switch and check for corrosion inside it. There's a How-To article on this forum, but I can't remember what it was titled and searching for "combination switch" will yield thousands of posts.

You may also want to double check the grounds for each of the parking lights as that will also cause the overheating you experienced.

E