Fuse 21 constantly blowing...any ideas?

[Stanley Rockefeller]

I have seem to be blowing my fuse 21. not sure why it's doing this, esp since the car is stock (no keyless entry, no aftermarket alarm etc.) aside from the aftermarket deck. Ive gone over the deck's connections and everything is tight with good connections. The wiring was all sealed up with butt connectors several years ago, with all the speaker wiring being re-done professionally. I've never had this (or any other electrical problem with fuses).

The fuse seems to be blowing whenever I open and close the rear decklid. All other functions that fuse 21 runs, is running them without fault until the trunk is physically lifted. Not sure when exactly the fuse is blowing, because when I have the trunk open the trunk light works perfectly. Only after I close the trunk do I notice that the fuse has since blown.

interior lights, tach, radio, OBC all function without a hitch.

Funny thing is, is that the problem has only first arisen when I replaced the spark plug wiring. Could this have something to do with the reference wire? I thought I've replaced it correctly, but is there something I'm missing?

thanks in advance.

[xwill112x]

fuse blowing would be a short to ground some where..

[Stanley Rockefeller]

Found the E30 Grounding Points:

G100 - In luggage compartment, behind battery (6 cylinder models with trunk mounted battery). In cars with batt in engine compartment - in engine compartment on right shock tower.

G103 - On right front shock tower (2.5i only). on 2.7 eta's its on left side of engine block, above starter.

G104 - on front fender, behind left headlight

G200 - beneath instrument panel, above brake pedal

G201 - On steering column, near horn brush/slip ring

G300 - Beneath left side of rear seat bottom

G301 - In luggage compartment

G600 - in windshield header

Should i go ahead and clean these grounds in hopes that it will remedy the problem? If so, should I just use some sandpaper to clean it with some dielectric grease to seal it up?

thanks in advance

[KenC]

Ba grounds usually won't cause the fuse to continually pop. You have a short somewhere in one of the systems powered by the fuse 21 circuit. Now you get to hunt ;).

[xwill112x]

its not the ground causing it to pop, the current is by-passing the load, and going straight to its own new found ground and popping the fuse.

[Stanley Rockefeller]

its not the ground causing it to pop, the current is by-passing the load, and going straight to its own new found ground and popping the fuse.

this


Any ideas of diagnosing where to find the problem?

[xwill112x]

so what all isn't working correctly? i had similiar issues a while ago (not sure if it was the same fuse) and it ended up being a penny in the bottom of the ciggarette lighter.

[Stanley Rockefeller]

everything works correctly when the fuse is not blown...then it blows and everything that fuse 21 runs, goes to shit.

[RobertK]

Had this problem a few weeks ago. Turned out the bulb in the trunk light had shifted slightly and was grounding the fixture.

Sounds like a similar issue, especially if you notice it when you close the trunk. Sounds like there is something loose in your trunk light fixture.

[Stanley Rockefeller]

Had this problem a few weeks ago. Turned out the bulb in the trunk light had shifted slightly and was grounding the fixture.

Sounds like a similar issue, especially if you notice it when you close the trunk. Sounds like there is something loose in your trunk light fixture.

Well, just got back from the garage...I think you may be correct Robert, as I had gone thru the glovebox light, rechargeable flashlight, and the connections under the hood. All checked out fine.

Then I proceeded to open the trunk...worked fine (llight illuminated) and everything worked correctly. The second I slammed the trunk closed, the fuse blew again :(

I disassembled the trunk light and everything seemed fine. No issues with wire insulation etc.


What was the problem on your light fixture Robert? and how did you fix it?

thanks in advance

[Stanley Rockefeller]

Just gave it another go with my last 7.5 amp fuse.

This time I tried removing the light fixture and removing the insulated pos. power feed to the trunk light fixture. Slammed the trunk closed once and everything continued to work...did it the second time and everything crashed again so I think i can safely say that its' not related to the trunk light, rather something else on the cars body.

Gonna cave and take the car in tomorrow morning. I've had this problem for a week or so, but I was hoping I could give my new mechanic a call to cancel our appt. i guess I'll be "paying" him I visit in the morning

thanks again for all your replies and help

[Stanley Rockefeller]

Just got back from the mechanics shop.

Last night after I was unable to find the problem, I was all out of 7.5 amp fuses, and had to drive 40kms to the repair shop. As a result I used a 10 as I didnt' wanna drive with no radio and no tach or OBC.

After I got to a nearby gas station this moring, i removed the 10, and replaced it with a 7.5 I bought form the gas station. After this I took the car to the repair shop.

After the tech (very reputable with an A+ review by the better business bureau, as well as many recommendations from this board) he was unable to get the fuse to blow. I returned to the shop to show him how I was able to get the fuse to blow and it wouldn't blow out for me either...I was like WTF, and he was like "why are you wasting my time ?!?!?!" I was like, "Im sorry dude, but I've been blowing through fuses like crazy until I put that 10 in there temporarily"....

So now everything's working properly even with the correct fuse....I tell ya, what a bunch of BS!!!

thanks again for all the help

[ibatic1]

Sorry to bump this, but i'm having the same issue. I found some mangled wires on the trunk hinge and cut and spliced them back. Now the fuse blows when the trunk lid is close as soon as the fuse goes into the box. It will blow a 10 and even a 15amp the same way. I have not tried anything stronger. I'm getting to the point where I am going to cut s319 which is where fuse 21 splices into all of its auxiliary's and rewire them all. Before I do that I would love some guidance on alternative routes.

[bobdavisnpf]

apparently you need to drive 40km, stop at a gas station, and take it to a mechanic ;)

[e30davie]

Find a list of everything on fuse 21.

Unplug all of them.
And disconnect .

Start plugging then in one by one until the fuse blows.