Horn Fuse

[Bald Eagle]

On my 1992 Jeep Comanche the Hd Lp Dly fuse (horn) keeps blowing the fuse.  I disconnected the horn wire and that didn't work. I removed the relay and that didn't work.  The fuse still blows.  As you put the fuse in, the top connector sparks.

Any suggestions?

[garyweb3]

Sounds like the wire to the horn is grounded somewhere.

[llhat]

would need to be between the horn switch and the appropriate terminal on the horn relay... (noted it still blows fuse with relay removed),    inside a harness somewhere........... 

[Gojira94]

Have you tried pulling the headlamp delay module to see if it stops blowing the fuse? It also looks like there is some common wiring between headlamp delay module and chime module. You might try pulling the headlamp delay and chime modules. If the fuse stops blowing and the horn works, add the modules back one at a time and see if the fuse blows again.

[llhat]

good suggestion on the delay and chime modules,  I had not considered those...

 

but from the OP's post

 

21 hours ago, Bald Eagle said:

. I removed the relay and that didn't work.  The fuse still blows. 

 

[Gojira94]

Right, with the horn relay removed the horn slip ring and ‘switch’ are out of the equation so there’s something else in the mix that’s shorted. The headlamp delay module essentially functions as a relay itself. Headlight switch pin H ties to headlamp delay module pin 6 and high beam select pin C. Headlight switch pin R goes to the chime module. Headlamp delay module pin 8 goes to the chime

module pin A4. If 91-92 also had direct loading of the headlight switch like 84-90 the headlight switch is also in question and deserves a look.

[Bald Eagle]

 Thanks for all the tips.  As for the Headlight delay module is that attached to the headlight switch (I am not sure where it is)?  There are two relays that are mounted with two screws under the bottom panel.  I have a PowerProbe ECT3000 tester and I pulled the relay off and tested each circuit.  The only one that did not record a short was the one going to the steering column.  There is only one horn on the driver's side.  With the wire attached to that horn, the wire on the passenger side for the missing horn shows a short.  When I remove the wire from the driver's side horn, there is no short.  Tried a different horn and no difference.  The tester has the probe that lets you trace or follow the short.  The only trace I could find is in the wire harness where all the wires come through the fire wall and into the main wire loom.  I suspect it may be where the two horn wires are connected, but as suggested, I need to check out the Headlight delay module once I know where it is and how to get at it.

 

[Gojira94]

Here's a good writeup and explanation on where it is and how it works:

 

 

[Bald Eagle]

Well, I removed the bottom panel, and the Headlamp Delay Module does not exist in the location as shown in the photos.  I could not see anything that resembled the module.

[Gojira94]

It may not have one, not all were equipped with it. We have lots of documentation on 87-90 stuff, not as much on 91-92. Some stuff is the same but some is different. This pic is from an old copy of Mitchell and it does show that the connector is next to the wiper switch connector like it is on 87-90. Also shows the 3 relay sockets including the horn relay.

 

 

I can post up some wiring diagrams if you want. Someone might have a FSM for 92...

[Bald Eagle]

I have the 1992 manual, and it shows the same diagram as you have shown.  If I am correct and the short is within the wire harness, it will be much easier and probably safer to install an aftermarket horn kit.

[Tactical Bacon]

If the rain lets up, I can go take a picture of the headlight delay module in my 1992. I have the fuse pulled in mine because I have a parasitic draw in either the delay circuit or horn circuit.