Scrap fiberglass, anyone...?

[k belknap]

I purchased an '81 Vette last week and have had some mechanical problems with it. I'm just about ready to drive it to the junk yard and get my $50 for them to crush it. I've had a constant overheating problem, the speedometer doesn't read correctly, and now the horn doesn't work. Seeing as how I've posted questions on the 1st 2 problems, I'll concentrate on the horn dilemma. It's simple...I press in on the horn and it doesn't work. I can't find any soltions in Haynes manuals or the Corvette Restoration book. Any ideas on even where to start? Oh yeah, did I mention the power door locks don't work? :~(

Thanks,

Kevin

[John W.]

Re: Scrap fiberglass, anyone...?

Welcome to the Club! As the owner of a car that is 18 years old you better get used to some problems. As the owner of a car that is made of fiberglass you better get used to electrical problems. They are not usually that bad, but they can be frustrating. You need two connections to make any electrical device work, a supply voltage and a return, (or ground). Metal cars use the body as the return, (or ground). Fiberglass cars can't do that.

One source of trouble in these systems is the wiring connectors. Wherever you find an inline plug you can lose the hot side of the circuit or the ground. Unplug and plug these in several times to see if you can break the corroded oxide on the contacts. This will often be the only problem. Clean these contacts with some good electronic circuit cleaner spray. When they are clean put a little non-conductive grease in the female connector to keep out the elements.

Horn - From the horn relay coil, you have a hot wire to your horn switch. The switch makes to ground when you push the horn button. If you can find your horn relay have someone listen carefully to it while someone else pushes the horn button. Do you hear it click.

NO! If not, put a voltmeter or trouble light, one wire to a good ground, alternator body or engine block where there is no paint. The other wire goes on either of the two hot wires you should find on the horn relay. You should now have 12 or 13 volts. Push the horn button. The voltage should drop to 0 - 1 volt. If not try the other hot wire. One of them should drop to 0 - 1 volt when the horn button is pushed. If the voltage drops, but the relay still does not click you may have a bad relay. If the voltage does not drop you will have to pull the cover off of the horn button. Check there for a hot wire first. If you don't find the hot wire check your connections back to the horn relay. If it is there try to jumper it to a good ground. This should make the horn work. Now find where you have lost your circuit.

YES! Your horn relay supplies 12 volts to your horns which are supposed to be grounded. Check with your voltmeter, or light, that when the horn button is pushed and the relay clicks, that the wire going to the horns is made hot (12 volts). If not you have a bad horn relay. If it is made hot you have a bad connection to your horns or your horns are not properly grounded. Check at each horn to see if you get the 12 volts when the horn button is pushed. If you do, your horns are either both burned out, not likely, or you don't have a good ground.

Hope this helps. By the time you get all of the electrical problems fixed on this car you will be a pretty good troubleshooter. Good Luck.

[John W.]

Re: Scrap fiberglass, anyone...?

Welcome to the Club! As the owner of a car that is 18 years old you better get used to some problems. As the owner of a car that is made of fiberglass you better get used to electrical problems. They are not usually that bad, but they can be frustrating. You need two connections to make any electrical device work, a supply voltage and a return, (or ground). Metal cars use the body as the return, (or ground). Fiberglass cars can't do that.

One source of trouble in these systems is the wiring connectors. Wherever you find an inline plug you can lose the hot side of the circuit or the ground. Unplug and plug these in several times to see if you can break the corroded oxide on the contacts. This will often be the only problem. Clean these contacts with some good electronic circuit cleaner spray. When they are clean put a little non-conductive grease in the female connector to keep out the elements.

Horn - From the horn relay coil, you have a hot wire to your horn switch. The switch makes to ground when you push the horn button. If you can find your horn relay have someone listen carefully to it while someone else pushes the horn button. Do you hear it click.

NO! If not, put a voltmeter or trouble light, one wire to a good ground, alternator body or engine block where there is no paint. The other wire goes on either of the two hot wires you should find on the horn relay. You should now have 12 or 13 volts. Push the horn button. The voltage should drop to 0 - 1 volt. If not try the other hot wire. One of them should drop to 0 - 1 volt when the horn button is pushed. If the voltage drops, but the relay still does not click you may have a bad relay. If the voltage does not drop you will have to pull the cover off of the horn button. Check there for a hot wire first. If you don't find the hot wire check your connections back to the horn relay. If it is there try to jumper it to a good ground. This should make the horn work. Now find where you have lost your circuit.

YES! Your horn relay supplies 12 volts to your horns which are supposed to be grounded. Check with your voltmeter, or light, that when the horn button is pushed and the relay clicks, that the wire going to the horns is made hot (12 volts). If not you have a bad horn relay. If it is made hot you have a bad connection to your horns or your horns are not properly grounded. Check at each horn to see if you get the 12 volts when the horn button is pushed. If you do, your horns are either both burned out, not likely, or you don't have a good ground.

Hope this helps. By the time you get all of the electrical problems fixed on this car you will be a pretty good troubleshooter. Good Luck.

[k belknap]

Re: Scrap fiberglass, anyone...?

John,

I cannot thank you enough for taking the time to answer my question thoroughly, with answers to different possible scenarios. No offense to anyone else on this board, but you are the first person to really offer something in enough detail for my little mind to be able to comprehend and actually fix the problem. The horn problem was, indeed, the relay. When someone almost hit me head on yesterday (and I discovered my horn didn't work), I just knew it would be an expensive fix...thinking that only because I thought the tilt/tele wheel would come in to play. You have saved me a lot of time and energy by responding to my post.

Thanks again!

Kevin

[k belknap]

Re: Scrap fiberglass, anyone...?

John,

I cannot thank you enough for taking the time to answer my question thoroughly, with answers to different possible scenarios. No offense to anyone else on this board, but you are the first person to really offer something in enough detail for my little mind to be able to comprehend and actually fix the problem. The horn problem was, indeed, the relay. When someone almost hit me head on yesterday (and I discovered my horn didn't work), I just knew it would be an expensive fix...thinking that only because I thought the tilt/tele wheel would come in to play. You have saved me a lot of time and energy by responding to my post.

Thanks again!

Kevin

[John W.]

Re: Scrap fiberglass, anyone...?

Kevin,

Thanks! You made my day!

Good luck on your door locks. They work just like your horn except the switch works without a relay.

[John W.]

Re: Scrap fiberglass, anyone...?

Kevin,

Thanks! You made my day!

Good luck on your door locks. They work just like your horn except the switch works without a relay.

[Tom Lempicke]

Re: Scrap fiberglass, anyone...?

In the aircraft industry we use a product called ACF-50. It is a corrosion preventative and will do wonders with connectors. Just like chicken soup - so what could it hurt?

[Tom Lempicke]

Re: Scrap fiberglass, anyone...?

In the aircraft industry we use a product called ACF-50. It is a corrosion preventative and will do wonders with connectors. Just like chicken soup - so what could it hurt?

[John W.]

Re: Scrap fiberglass, anyone...? ACF-50..?

Tom,

Is the ACF-50 used as a non-conductive protection or as an enhancement for conduction. I have used a copper emulsion never-seize before for an enhancement for conduction, but on these type connectors you must be very careful not to smear it where it can contact two circuits at a time.

Where could I find some of this ACF-50?

John

[John W.]

Re: Scrap fiberglass, anyone...? ACF-50..?

Tom,

Is the ACF-50 used as a non-conductive protection or as an enhancement for conduction. I have used a copper emulsion never-seize before for an enhancement for conduction, but on these type connectors you must be very careful not to smear it where it can contact two circuits at a time.

Where could I find some of this ACF-50?

John

[James F.]

[James F.]