Need help, no horn or dome lights

[19Blazer80]

Everything else outside works, but inside is another story.

Both dome lights, the horn and the door buzzer(not that I mind that one) don't work. I tested the fuses and they all work. It looks like all the right sizes too. So I'm kinda stumped, what else can I check? Oh and I did change the bulbs in the dome to see if that was the problem with those.

Thanks, Mike

 

[89Suburban]

I never personally even identified what the horn relay looks like or where it is located so this is a learning experience for me as well. I been pouring over wire diagrams for the past hour. This is what I came up with. What I am assuming is the horn relay should be located somewhere under the dash in the driver's side area. Newer model trucks have a "Convenience Center" which is a separate smaller panel from the fuse panel that holds the relays for the 4/ways, buzzer, horn, etc. Looking at your year diagram I only see a 3 prong plug/relay for the horn under your dash. That plug should have 4 wires:

- 2 orange wires to one terminal, one orange is the feed from the fuse box, the other orange actually runs to and feeds the cigarette lighter. Right there is a test you can perform and see if your cigarette lighter is working and has power, if so, there should be power to the horn relay also.

- 1 black wire that comes from the horn button on the steering column. That is the ground signal to trip the relay.

- 1 dark green wire that goes through the firewall and feeds the horns themselves.

Here are a few charts from later years that you can use. My 1980 diagrams are a bit blurry so you would be better off working with these. Hope this helps.

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[19Blazer80]

WOW that is a lot of things to check that I have NO idea how to do. Guess I need to learn how to use a multimeter and test lights lol

 

[chengny]

Cigarette lighter is on that circuit and often shorts out. Try pulling the wire off the back of the socket and put in a new fuse.

 

[19Blazer80]

I checked the fuses, they are all good. Never actually checked the lighter though.

 

[chengny]

I checked the fuses, they are all good.

With a meter or by visual inspection?

Before tearing into a perceived wiring/component problem, pull the circuit fuse out of the panel and confirm continuity with a meter (or switch it with a known good fuse). Here is my boilerplate speech:

People get sick of hearing me saying it (especially my sons; because they know virtually everything ) - but it is always prudent to check fuses with a Fluke or by switching with a known good one - before tearing things apart.

When you think about it - it makes sense. During it's lifetime, some fuses get violently yanked out with needlenose pliers and shoved/wiggled back in dozens of times. The greatest mechanical stress on the fuseable wire occurs at the ends where it connnects to the stabs. As soon as that joint starts to grow thin, resistance/heat increase. That starts a vicious cycle and after a while it fails.

The fusible link that is visible in the middle window is only reliable in detecting instantaneous failures due to high current.

 

[19Blazer80]

I used a fuse checker that comes with the fuses. Has two metal prongs that you touch to the fuse, it lights up if its good.

 

[89Suburban]

WOW that is a lot of things to check that I have NO idea how to do. Guess I need to learn how to use a multimeter and test lights lol

Don't let it overwhelm you. Can you get the interior lights to turn on by turning the headlight knob?

Do you have a test light?

 

[19Blazer80]

OMG, I never thought to turn the knob. I feel lile a moron now. LOL The lights came on turning the knob, so I guess it's the door switches?

No test light, where would I get one?
And where is the horn located, I looked around the grill area but its getting dark and couldnt see it. When I puch the horn on the steering wheel I hear a click from the drivers side dash. So I'm thinking there might not even be a horn to beep.

 

[chengny]

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[19Blazer80]

Went and looked again with a flashlight. Looks like there is NO horn anywhere. I did find a green wire near the battery that wasn't attached to anything.