No spark, horn fuse, what's the deal?

[hemi2112]

So I figured out that the reason for my sudden no spark on my 88 GL was due to a blown #5 fuse, aka horn, clock, hazard. I put in a new fuse and it blew again. Now I've had problems recently with the clock coming on and off at strange times, so I'm thinking I possibly have a bad ground or something. I'll go out and check some more.

 

I've seen several threads talking about this, but have yet to figure out exactly why. In the wiring schematic, it shows the black/white wire going to the ignition relay. So is there anyone who can clearly explain what's going on with this circuit? It seems like it's pretty common and would help a lot of people on this board.

[Gloyale]

Open the glovebox. Twist it slightly and you will be able to slide the stoppers out through the grooves and open it further. All the stuff in you're glovebox will fall out so you want to remove that all first. Now if you reach up toward the clock, you should be able to find the clock plug. Blue or white, 6? pole connector, but it only has 4 wires on it. You could just unplug it and see if that's the problem.

[Cougar]

While a bad ground will not in itself cause a short a ground connection in the wrong place, like touching a power lead, will cause a short.

 

I would check the horn area and overhead light for the trouble. Since the horn is the most likely suspect in my estimate I recommend you check that first. My info shows the fuse supplies a lot of places and it may help you to track this trouble down by replacing the fuse with a brake light. This will limit the current to the short to a safe limit and allow you to disconnect things to see if you can find the correct path the problem is on. When the short is isolated from the power the light will dim or go out.

[GeneralDisorder]

Your clock problem is unrelated most likely. The EA82 clock's all have this problem - remove it and remelt the solder on the circuit board and it will work fine again.

 

And poor grounds don't cause blow fuses - they cause things to NOT draw current, rather than to draw too much current.

 

Plug in a lamp to the fuse socket and start going through the items on that fuse - when you find the short the light will dim or go out.

 

GD

[hooziewhatsit]

I believe the ECU is also on the horn fuse. So if that fuse keeps blowing, you won't have the ECU, and you won't have spark.

 

-Dave

[calebz]

I believe the ECU is also on the horn fuse. So if that fuse keeps blowing, you won't have the ECU, and you won't have spark.

 

-Dave

 

 

+1

 

IIRC, RXSNRG found this out the hard way a couple years ago.

[hemi2112]

UPDATE:

 

So off of the horn fuse came a single white wire, which 6" downstream was tied into: two green wires along with the original white wire . It looks like the previous owner may have done this, or maybe it's factory, but I'm not sure. Anyway, after disconnecting the wires and trying them individually to find which was causing the short circuit, I found out that the white wire went to the hazard switch on the dash.

 

After jumping 12v to the hazard switch, thereby bypassing the white wire all together, smoke began coming from the trouble spot. The culprit was a bare wire in the stereo wiring which was shorting out on a bracket.

 

Thanks for everyone's help. The clock still doesn't work, but I'll address that later.

 

The moral of the story for anyone searching is that the #5 fuse for a seemingly benign circuit such as horn/hazard/clock, is actually tied into many things which may present itself as no spark at the coil, and prevent your car from starting.

 

Cheers.

[seattlelegacy]

Plus one more.

 

I was trying to reinstall a stereo after my GL was stolen (and recovered) and one day it just wouldn't start. No spark at the plugs, dist, not even the coil. Fine, the coil was cheap so I bought a new one, still no dice. Checked all the fuses, noticed that two were shot: horn and wipers. I assumed this had nothing to do with the starting. WRONG. after reading this thread, the car runs just fine. Who would have thought?

 

JOrdan

[subiemech85]

and on a previous ea81 my dad drove, one day it just died

no spark, no run, his soulution was to throw parts at it, distributor, etc.

 

problem: blown fuse