Fuse Gremlins!

[gema]

What could be causing my dash/sidemarkers/etc. fuse to blow? '72 240z, Right side, 3rd down from the top. On closer inspection, the PO had a washer wedged in between the contact and the fuse, but I don't know why that would blow it. Any ideas? I'd really like to have all my lights working! Thanks in advance.

[Victor Laury]

This has been cured in the past by several members. I, am not one of them. The car I had this problem with, got parted-out before I cured it. (that fixed it for good )

It has been found in some cases that there's a high resistance contact in the aging light switch stalk.

In others, a fault was found in the marker lights connections (one was reversed or light sockets were corroded).

but first, really ensure you get the best possible contacts at the fuse box. really clean those contacts to shiny brass, squeeze them togther then install a new fuse. If it blows again, read the recent write-ups on refurbising the light stalk. Or replace with new, if availible.

[sblake01]

I don't know if this will help, but it's another place to check. When I put a new console in my 78, I inadvertantly caught the wire for the ash tray light with one of the screws that holds the console in place. Evey time I turned on the lights, I'd lose that fuse.

[gema]

I'll be giving the fuse box a vinegar bath and emery board treatment tonight. I'm also bringing home a big box of fuses :: On that note, which kind are they again? AGC-I forget the rest... As for the light stalk, anyone have a part number handy? I am at work (At Nissan) and could check price/availibility in a jiffy. I just PRAY it's the fuse box or the stalk...I don't want to have to tear my car apart looking for the cause.

[civ104]

I show part # 25160-E8800 for models produced from 0971 to 0672. After that date, try 25160-N3300. Hope this helps, thanks to the Z Microfiche CD.

[Mike]

Originally posted by civ104

Hope this helps, thanks to the Z Microfiche CD.

Yeah!! That's why we put it together! Glad it was a helpful tool for your project.

As far as the lights go... there have been many threads about resistance caused by the fuse block itself. So, you might want to pull it out for a good inspection. That baby is an essential part of a wiring system, if you have a bad one then you'll be in for a lot of frustration. If you have the cash, buy one of the new circuit board replacements by MSA.

If you are poor like most of us, you might want to debug the system by removing one piece at a time. Make sure you go out and buy a CASE of replacement fuses.

-- Mike

[civ104]

That's why I have two. One for home, one for helping answer questions like this at work, time permitting.:classic: :classic:

[gema]

I'm planning a few evenings of debugging and unplugging...testing the fuse block, the headlamp switch, and the side markers...

The fuses are AGC-20, right???

[civ104]

Roger that!

[gema]

Okay, here's an update.

With the car off and the keys not in the ignition, I place the fuse in. All is well. Flip on the lights, and ...fizzle fizzle pop. Would this be pointing me towards the light stalk? Thanks in advance.

Edit: Even if the fuse is popped, the headlights still turn on. This mean anything?

[Victor Laury]

it sounds like a true short in the sidemarkers or dashlights or rear running lights or cigar lighter(?)

What was disturbed lately?

[gema]

My headlight switch is sitting disassembled on my table, soaking in vinegar overnight. Let me detail exactly what has happened with the car, electronics-wise.

When I bought it:

Taillamps were all messed up, chopped wiring, etc. Yet the running lights still worked when I turned the headlamps on. No sidemarkers, turn signals, or dash lamps.

When I changed the taillight bulbs:

Still messed up, but everything lit, but NOW the running lights didn't work. Still haven't figured that one out.

When I changed the taillight harnesses:

Everything is in its right place and all the lights work accordingly, with the exception of the running lights. No sidemarkers, dash lamps.

The hazard switch worked yesterday but not tonight after I finished tampering with the fuse box (trying to pull it out, but someone had attached some wires to it, making it impossible to totally remove...some PO had a fun time attempting a stereo install, maybe? Also, I touched something to something else and sparks flew out...decided to disconnect the battery after that ) The cigar lighter definitely works, I checked with the tip of my finger. It did get REALLY hot in a very, very short amount of time though. I mean, less than a second was enough to make my finger smart pretty badly. Is that normal?

There IS something sketchy about the tail harness, though. There is a cutout of the plastic tubing where a black wire is held together with red electrical tape, obviously something Nissan didn't do originally. Perhaps I should check this connection? I don't care what it takes, I HAVE to get past this problem...everything works except what I need!!!!