C2 1967 Electrical Question (Horn/Amp Gauge Issue)

**Joe R.** · May 17, 2018, 07:36 PM

Re: C2 1967 Electrical Question (Horn/Amp Gauge Issue)

By any chance did you replace the wiring harness with a Lectric Limited wiring harness?

If you did that's where I would start looking.

JR

**Richard M.** · May 17, 2018, 07:40 PM

Re: C2 1967 Electrical Question (Horn/Amp Gauge Issue)

Stephen,

I took a quick look at the wiring diagrams. I see 2 possibilities and they both concern the "inboard" bulkhead connector at the firewall, engine side. Either in the fuse panel block or the engine harness mating plug. There are 8 pins in this plug connection.

1- The 2nd row of pins in the plug block are shorted to each other. Remove the inner plug from the inner bulkhead connect and check for visible pin shorts. It could be in the engine harness plug OR the mating plug at the firewall(fuse panel block).

or

2- There is a harness miss-wire in either the 2nd row of pins in the fuse panel block or the associated 2nd row of pins in the engine harness mating plug.

In the 2nd row of this connection block, there is a black wire on each pin next to each other. One is a 20G Black which comes from the Horn button. This gets grounded when you push the horn button. The adjacent is a 16G Black wire which has constant 12V from the Battery Cable post at the Starter solenoid.

If these were shorted, when you push the horn button it would apply Ground to the 16G Black wire that has constant 12V. If so, the Fusible Link(at the starter solenoid) would probably last longer than the horn button internal spring wire. Another possibility is these are shorted internally in either harness.

If these 2 Black wires were reversed in either the Main Harness plug or the Engine Harness plug, that might also cause a fault like you're seeing.

Rich

**Stephen F.** · May 17, 2018, 07:42 PM

Re: C2 1967 Electrical Question (Horn/Amp Gauge Issue)

Originally posted by Joe Ray (1011)

By any chance did you replace the wiring harness with a Lectric Limited wiring harness?

If you did that's where I would start looking.

JR

Yes, I did use Letric Limited and I called the tech help line. They said to replace the horn relay. I did and it was no help. Any other help out there?

**Stephen F.** · May 17, 2018, 07:51 PM

Re: C2 1967 Electrical Question (Horn/Amp Gauge Issue)

Thanks for the suggestions. I'll look at these connections asap.

**Stephen F.** · May 22, 2018, 04:40 PM

Re: C2 1967 Electrical Question (Horn/Amp Gauge Issue)

Rich,

You were correct - the problem was a pin short at the bulkhead connector. My error I guess when plugging the connector in. Pin was bent over and touched another pin. Issue has been corrected and AMP gauge & horn work. Thanks so much,
Steve

**Richard G.** · May 22, 2018, 10:22 PM

Re: C2 1967 Electrical Question (Horn/Amp Gauge Issue)

Diagnosing electrical issues over the internet is extremely difficult.
Richard dug deep into that one. Help line just shotgunned it.
Amazing! Excellent job Richard.
Kudos for the good problem description.
NCRS group is an amazing thing with talented people.
Rick

**Mark E.** · May 23, 2018, 06:05 AM

Re: C2 1967 Electrical Question (Horn/Amp Gauge Issue)

Amazing diagnosis, Richard M.

**Richard M.** · May 24, 2018, 09:42 AM

Re: C2 1967 Electrical Question (Horn/Amp Gauge Issue)

Glad it all worked out. And thanks for the compliments.

Rich

**Tom D.** · August 29, 2018, 08:17 PM

Re: C2 1967 Electrical Question (Horn/Amp Gauge Issue)

Richard - I sent you a note prior to reading this. Please let me know if my '66 300 HP problem is like this above.
(I have 12 volts at the coil, even when the ignition key is off. This should be 12 volts when cranking, but not when the ign. is off.)

In another prior post, someone said this would cause points to burn in a low amount of miles, which I found to be true. I now turn the battery disconnect off each time I park the car. I can hear the horn relay (or something like it) click when I shut off the battery power. Comments?
Thanks for your dedication to NCRS.org.

**Richard G.** · August 30, 2018, 07:24 AM

Re: C2 1967 Electrical Question (Horn/Amp Gauge Issue)

Does your horn work?
Is your car an AIR car?
It typically is fairly easy to track down the clicking sound.
Have another person connect and disconnect and reconnect the positive cable while you track the sound down.
Only other equipment that may click is the clock. It will not be very loud so i doubt that is it.

**Gene M.** · August 30, 2018, 08:22 AM

**Richard M.** · August 30, 2018, 12:51 PM

Re: C2 1967 Electrical Question (Horn/Amp Gauge Issue)

Originally posted by Tom Dingman (4889)

Richard - I sent you a note prior to reading this. Please let me know if my '66 300 HP problem is like this above.
(I have 12 volts at the coil, even when the ignition key is off. This should be 12 volts when cranking, but not when the ign. is off.)

In another prior post, someone said this would cause points to burn in a low amount of miles, which I found to be true. I now turn the battery disconnect off each time I park the car. I can hear the horn relay (or something like it) click when I shut off the battery power. Comments?
Thanks for your dedication to NCRS.org.

Tom, I got your note. When did this problem occur? A history of the problem, how long you've owned the car, was the problem after recent work on the car, etc would be helpful? What electrical modifications? Electric fans? High power Stereo, Alarm, Etc? What test tools do you have: Testlight? Volt/Ohmmeter?

This is all somewhat of guess at this point. I think you may have 2 unique problems causing your issues. One is the Horn circuit, other is the IGN circuit. I don't think they are both caused by the same fault, however, you won't know until the problems are solved.

As always for safety, temporarily disconnect battery when diagnosing, reconnect to test.

Problem 1 - Horns continue to blow, Relay making noise on battery disconnect:

If it is in fact the Horn Relay making noise, and as you said(in the PM to me) the horns continue to blow with battery connected, I'd disconnect your horn relay feed wires from the 2 blade terminals underneath. One goes to the horn button, other to the horns. The Horn relay may simply be defective(internal short, Bat+ to Horn terminal). OR it could be that your horn button is stuck on, or a wiring short to ground, therefore always supplying ground to the activate the horn relay. Remember that the top terminals of the Relay Buss are constant battery power.

Problem 2 - Constant 12v on IGN circuit:

Several Possibilities: (Hint, Check #3 first)

1 - A short in the ignition switch(internal short in the switch). Easy test would be to remove the harness plug on the back of the IGN switch and retest. OR remove the lower terminal at the ballast resistor(Pink? from IGN switch via firewall grommet), measure it with meter and then coil+. Top terminal of ballast goes to coil+, and also via a 2nd smaller gauge wire on the coil+ to solenoid "R" terminal.

2 - A short in the Main harness. The Main harness has the +Bat(Red) and the IGN(Pink?) wiring embedded. The above tests will help isolate if the short is in the harness as well.

3 - A internal OR external short at the starter solenoid "R" terminal circuit. Check the Bat+ cable at the starter solenoid. It is possible that the cable terminal end has slightly loosened and is contacting the "R" terminal stud on the solenoid, or the R terminal is internally shorted in the solenoid.

Rich

**Tom D.** · August 31, 2018, 07:36 AM

Re: C2 1967 Electrical Question (Horn/Amp Gauge Issue)

Thanks guys! Good stuff above. I am dealing with a valve train issue for my Altoona Entry (not this car). I'm going to take your suggestions ASAP. Thanks again!