V4motorsports

Working on the horn this morning and traced everything out and found I was getting no power to the horn relay. took off the red wires and removed the horn relay.

Tested it and found it was ok but the power wire to it wasn't connected fully. Cleaned up the metal cover and then painted it.

When I reinstalled it to the fender well, one of the wires touched the master cylinder and shorted out. Now, I have no power to anything!!!!!!

Which fusible link should I be looking at?

Thanks

Russ

P.S. I know...should have disconnected the battery but forgot about it.

V4motorsports

Need to figure this out, holding up other work.

Thanks

Russ

sullyman56

My guess would be one of the fusible links coming from the horn relay.

henrikse

you have one at horn relay one at starter and one to the right of Wiper motor. Check them all you will see it split apart

V4motorsports

After reading about fusible links, I think they are slow burning fuses. So, if the wire touched the brake cylinder and shorted out, would that have been enough to blow a fusible link?

I've checked the fuses and didn't find any that were blown.

I have absolutely no power once I turn the key.

This has me really stumped.

Thanks

Russ

Cavu2u

I know you're looking for an answer for a quick fix, but that's not always possible with electrical circuits. I have a schematic for my car's year, and I'd start at the Battery. Big cable goes to the Starter, so I'd check for voltage there. From the Starter, a harness picks up power from there, to .... well, that's where the schematic comes in. So I'd check for voltage where that wire terminates, and then from there... and on, and on. Not too many Fusible Links in the car, and if your fusebox is dead but the fuses in it are good, you can narrow the open down fairly fast.

Good luck.
Steve

V4motorsports

Thanks Steve

Not looking for a quick fix, just a starting spot or educated guess. When it comes to electrical, I really don't know much about it.

But your suggestion has at least given me something to start with.

Thanks

Russ

SwampeastMike

Fusible links amount to a short section of smaller gauge wire inserted into a length of higher gauge wire. Like so-called "slo-blo" fuses they allow a fair amount of over current to pass for a few seconds before blowing. They will however burn in half almost instantly with a dead short. Again, there aren't many in the car and you'll see split/burnt insulation around the link.

V4motorsports

Thanks for your help. Will need to look at the AIM and trace the wires. Just need to find out where they all are.

Thanks again

Russ

Peterbuilt

Start at the STARTER SOLENOIDand follow the RED wire until you see 'fusible link'
Then go to the HORN RELAY and check that one.

https://docs.google.com/viewer?a=v&p...DcxZjZkOTdhNGU

V4motorsports

Wow, that certainly makes tracing the wires easier!

Thanks

Russ

V4motorsports

OK,

Finally had a chance to check a few things out.
1. Checked the battery cable at the starter and had 13.3V.
2. Disconnected the red wire from the starter and the horn relay and tested the wire. Had continuity through the wire.

There is a fusible link at the horn relay, where is the other end of that wire so I can test that section? I don't see any burned insulation at the fusible link, so not sure if that's the problem.

Thanks

Will continue to check tomorrow.

Russ

Rescue Rogers

Hey Russ, All your power goes from the battery to the starter, then its routed from there to the ignition harness and your light harness and into the fuse block. Can you tell us the year of your car please.

Check for good grounds as you check for power. I dont know the year of your car but you should have a couple of red wires all connecting to your horn relay, it acts as a bus bar. Check the continuity from the starter to the horn relay, there is a Fusible link down at the starter and another near the wiper motor on my 68. I had a pic of my old harness that should be close enough for you to see how its wired.

This pic was for a wiiper problem but it will work for you, The blue arrows point to the red wires at the horn relay and the other arrow are the wires at your starter. (These are 68 colors) Connected at the starter, you will have a red one with a big lug=power to the relay bus bar, black = ground, goes to the bolt holding the starter in, small lugged ones which were purple =ignition switch power to the solenoid to start the car and a yellow that is power to the coil

You can see the fusible link just up from the red terminal lug for the starter. The harness firewall connection is under the master cylinder and you can see it easily from underneath the car. If you have a test light it makes finding power quicker than a meter, just hook it to a good ground and go probing at terminal connections or stab through the wire, it would help at the fusible links. I will look tomorrow to see where the power goes to teh fuse block, i think it goes from the bus bar back though the light harness into the fuse block. Look for power at the fuse block

Hope this gets you in the right direction until I can get more info for you

Rescue Rogers

I'm rereading your post and it seems you have power at the starter, and continuity from the starter to the relay? if that is true check where you are grounding. good Continuity would rule out the fusible link being bad unless you are checking the wrong wire. There should be 3 red wires attached to the relay.

If I remember the power goes from the relay buss bar to the headlight switch, as a junction, then to the fuse block for distribution. I'll try and get more info today

V4motorsports

Sorry Rogers, my car is a 71

Ok,

Went out to the garage, disconnected the red wire from the middle lug on the starter and then disconnected the wire from the horn relay.

When I turned on my multimeter to ohms, it showed "OL" not connected to anything.

I then connected my multimeter to a known good wire and it showed 0.00


I then connected my multimeter from one end of the red wire to the other and it showed 3.50.


Is that showing me the wire is bad?

Again, I'm a complete idiot when it comes to the electrical systems on any car.

Thanks for any help

Russ

henrikse

When you are connected with your ohmmeter you should read a dead short (ie 0.0) as a lead on each end is a short. Reading 3.5 ohms on a piece of wire with a fusible link is weird at that would draw about 3 to 4 amps which is way too much. There is some resistance but not that much. It should read close to 0. Are you sure you have a clean connection onyour meter leads and wire? Anyway this is not your problem . Use you voltmeter and see if you have 12 volts at battery wire at starter with other end on ground. Then same at the hornrelay

V4motorsports

Just went out again (after watching some YouTube videos) and tested the red wire going to horn relay, NO continuity! Guess I burnt out the fusible link.

There is no loop like Rescue Rogers shows, guess I'll have to unwrap the harness to find it.

Oh boy, here we go!!!!!

Thanks for all the help

Russ

Rescue Rogers

try setting your meter to the diode seeting, one click clockwise and cross the wires. it should give you an audible tone. i usually use this setting looking for continuity, that way you can move quickly and not worry about slipping off a terminal while your trying to read the resistance. keep us updated

Rescue Rogers

I don't know if the 71 has a loop like the 68 but somebody should chime in on that or post a pic.

I found this

https://www.corvetteforum.com/forums...r-20wipers.jpg

V4motorsports

I did that using my power probe. Used a good wire and touched both ends and got an audible sound. Went to the red wire from the starter to horn relay, touched both ends and nothing. Touched the good wire again and got a sound.

I am assuming that now I have isolated the bad wire. Following the starter wires towards the firewall, it looks like someone was in there for whatever reason because there is electrical tape wrapping the wires that isn't the original tape.

Thanks

Russ