Horn/DM Fuse keeps popping

4C FED

4C FED

Absolutum Dominium
I reconnected the battery a couple of weeks ago to upload the FAST startup program.
The following weekend I found the radio was dead.

After poking around I found that the Horn/DM fuse was popped. While troubleshooting I could see a constant 7 amp draw with nothing on.
When I disconnect the fusible links behind the alt. the draw is about .5 amps.

Today I spent most of the day chasing this gremlin.
Now I can hear something in the dash cycling. It sounds like a re-settable fuse turning off then on.
When I put my DVM between the + term. on the battery and the + battery cable I'm drawing 1.7 amps, then it jumps to 20 amps and drops back to 1.7 amps.

I've pulled the horn relay and that didn't make a difference.
I fixed a short at the dome light, no difference.

Here is something that I noticed, maybe a clue; With a good Horn/DM fuse, the interior lights work normally (door open, lights on. doors closed, lights off). If the Horn/DM fuse pops, when the door is open, the underdash lights are on and the dome light is off. When the door is closed, the dome light is on, underdash lights are off.

I've left the battery disconnected for now because I'm afraid something is gonna fry.

Anybody have a previous experience like is or any ideas on where to look?

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smallbabygeek.jpg

Rick
Sy#458
Galt, CA

<font size=-1>[ This Message was edited by: 4C FED on 2002-03-17 23:20 ]</font>

<font size=-1>[ This Message was edited by: 4C FED on 2002-03-17 23:22 ]</font>
 
SYO237

SYO237

SyTy Registry
i have a similar prob...

only its when i plug something into the cig lighter (cd player, phone charger)...

i hear a pop and it kills the radio fuse which runs the radio, interior lights, and fog lights...

ideas? gotta carry a pack of 20 amps with me everywhere...sucks...
 
4C FED

4C FED

Absolutum Dominium
Umm, dunno. I have heard before that the cig. lighter was problematic.

I was looking at the maintenance manual last night and I think I need to look and all of the interior lights, sockets & their connectors and make sure something is not grounded.

Thanks to this I did find a trick little item. It's a fuse that has a LED in it. When the fuse pops, the LED illuminates taking all of the guess work out of which one it is. They are a little pricey @ a $1.99 for 2, but if it adds a little sanity to this insane piece of machinery, I don't mind.
 
B

bigjohn

New member
rick, sounds like a wierd short of some kind. have you been into the dash lately? could be the dome light switch or in that circuit.
 
4C FED

4C FED

Absolutum Dominium
Yes, I have.

As a matter of fact I broke the glove box light switch the other day when I was trying to square away the FAST harness.

Then I had the radio out while I was trying to find the 7 amp drain.

Like I said, it sounds like a thermal/resettable fuse is opening and closing inside the dash somewhere.
Does the cig. lighter use such a thing?
 
TYPHOOL7

TYPHOOL7

Post Hawk
i also had that problem, i dont remember what i did ito fix it. every time i turned on my fog lights, the horn fuse would blow and the dome light would come on. i think i ended up just putting a bigger fuse in and it went away but im not sure.
 
4C FED

4C FED

Absolutum Dominium
I tried a bigger fuse, not much bigger. Went from the 20 to a 25.

Thats when I started hearing the crispy crackle noise under the dash. Figured I'd better just disconnect the battery until I could spend some more time on it.

Oh well, it's gonna have to sit for a week or so. I just got the word I've gotta fly to Japan tomorrow.
 
myclone

myclone

Donating Member
OMG... I had/have the same prob. Heres what Ive noticed/found so far...

When messing with the cig adaptor to get good connection for the power inverter for my laptop it pops this fuse %75 of the time.

Interrior lights act just like was mentioned above. No running lights at all, only the headlamps work. No inst panel lights. No radio (like the stocker worked that good anyway :roll: ).

I havent been able to track down exactly what the prob is but I have managed to decide its the cig lighter socket. NO, zero, nada probs if I run the laptop off of its internal bat and not mess with the cig lighter. Its even blown the fuse just lighting a cig a couple of times..

As for the popping/clicking/resetting sound... I dunno. Mines never done that. There looks to be a self resetting breaker in the fuse panel that could be making the sound youre hearing (it plugs in like a reg fuse but has a metal cover on it and is in the upper right corner of the fuse panel...I think). If this is happening just by connecting the battery then whatever has shorted is still shorted.

If I were you Id pull the radio trim plate and disconnect the cig lighter plug. If it still does it then you have some wiring that has melted togeather or to ground (remember, ya said you heard some "crackling" form under the dash when you put a 25A fuse in there...).

On a side note: Carrying spare fuses can be a pain to keep up with... In a pinch or if youre stranded just use the metal foil off of a gum wrapper or outta a cig package (or any foil for that matter) and wrap it around the fuse. Reinstal fuse/foil. Ta daaaa.... Instant cheap fuse. It will work good enough to get ya home.

Poor ppl got poor ways ya know :grin:

_________________
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<font size=-1>[ This Message was edited by: myclone on 2002-03-18 15:10 ]</font>
 
myclone

myclone

Donating Member
On 2002-03-18 16:02, 4C FED wrote:
vmailpic.jpg


WARNING! Loose nut behind the keyboard!

That picture is scary.
Click to expand...

Ha... Thats my Sunday goin to meetin look..

_________________
vmailpic.jpg


<font size=-1>[ This Message was edited by: myclone on 2002-03-18 16:36 ]</font>
 
Christian Dionne

Christian Dionne

Member
Mine used to pop the radio fuse, then when you open the door the dome light would shut off and the station memory would be lost. Then a few months later my cig lighter started popping fuses if I plugged my cell charger or inverter in. Just buy a new cigarette lighter or power output instead if you don't smoke. That solved all the fuse problems, and the voltage is higher at WOT on Datamaster! HTH,
 
V6 Kompressor

V6 Kompressor

New member
Please don't put foil around a fuse... I have some parts of a 92 tys guts due to an electrical short from a stereo install...burnt it almost to the ground. There is a Circuit Breaker on the power door lock circuit that will do exactly what you are talking about with the key off... There is another circuit breaker in the fuse box for the windows, but the key has to be on for this one to get hot. I found the faulty circuit by touching the circuit breaker with my finger and it burnt the shit out of it... I had 20A12V imprinted on it for about 6 months, until I cleaned it off when I was cutting a heater hose off the heater core tube with a razor knife!! :grin: I believe the last one like this I had was a stuck door lock switch. If you need a schematic of the Cig. ckt./ door lock ckt or whatever, email me and I will get it to you... Steve.
 
4C FED

4C FED

Absolutum Dominium
Thanks guys,
I've got the drawings, now it just has to wait until I get back next week, maybe.
 
V6 Kompressor

V6 Kompressor

New member
On 2002-03-17 23:58, SYO237 wrote:
i have a similar prob...

only its when i plug something into the cig lighter (cd player, phone charger)...

i hear a pop and it kills the radio fuse which runs the radio, interior lights, and fog lights...

ideas? gotta carry a pack of 20 amps with me everywhere...sucks...
Click to expand...

Cigarette lighter socket is bad, replace it, or have it replaced....
 
4C FED

4C FED

Absolutum Dominium
WooHoo!
Problem found and fixed.

Previous owner had installed a powered sub. box behind the drivers seat.

Jump ahead to 6 months ago when some jackass replaced the carpet (Me) and didn't notice that the 12 volt & grnd. line to the sub. were pinched under the pass. seat bracket.

It was tough to find, due to the way the guy had wired it up. I unplugged it at the sub. but that didn't make a difference. Not until I cut the supply wires behind the radio could I tell where it was.

The funny part is that the 12 volt & ground lines are double insulated. The normal insulation around the wires then another heavy PVC jacket around the pair.
I cut out the pinched part and dissected it. The wire insulation was not broken anywhere that I could see. Hmm, weird stuff.

I changed the way its wired now, so it's a lot cleaner and shorter.

I only a few milliamps draw now. Now I can finish wiring the guages and what not.
 
4C FED

4C FED

Absolutum Dominium
Well this dang thing popped its ugly head/fuse again. :evil:
I dunno WTF is up with it.
So far I have removed the 2 courtesy lamps under the dash and all is fine.
Maybe I'll just leave it that way.
 
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