Black wire to Fuse links is 15 Volts

[1967LCC]

Hello all,

I edited my original post because I got out of "stuck on stupid" mode....

Trying to get my top to work and was checking some wiring. There is a black wire that is connected to the two fuse links that run to the two blue wires on the BUS BAR.

I measured the volts on the black wire (car started) and it measured 15 volts. Is that too hot? Battery jumps up some from 12.5 when the car is runnibg but no where near 15 volts.The fuse links are fine. But curious if there will be any ill affect further down the line. Would it set off a circuit breaker?

I was thinking to let it be and run the fuse links off the battery side of the starter relay and keep diagnosing. But kind of weirded out that the black wire has more juice than from my battery to the starter relay.

Appreciate the help.

Rich

[action]

Fuse links, circuit breakers, and fuses are not that voltage sensitive. They are current sensitive. Most are heat sensitive and large amounts of current create heat

With that stated you can not have more voltage than the alternator produces when the engine is running. And the battery produces no electricity it stores electricity. For the typical charging system the alternator should produce 13 high to 14 low in voltage. Less than that and the battery will not be charged. More than that and the battery will get over heated and boil out. A 12 volt battery totally charged up should be about 12.6 at rest with no load. In actual practice if the voltage is over 12 and close to that 12.6 likely it is fully charged. Measuring for voltage is EZ however isn't that accurate for determining state of charge.

If you are measuring 15 volts somewhere, there is an issue. Either the charging system is producing too much voltage or your means of measuring it is an issue.

Hope that helps.

>>>>>>>>>>>>>>>>Action

[1967LCC]

Thanks and it did help. I had a "duh" moment after reading your response. Makes perfect sense. I get a little goofy sometimes trying to figure this stuff out. Too many wire, switches, relays, etc.

So definitely measuring right. One thing I did not include in my post was that I disconnected the wiring for an aftermarket Amp gauge (not working) to simplify things. Not sure how or if that plays into things.

Going to check the alternator reading and report back.

Thanks again,

Rich

[Dan Szwarc]

I downloaded your previous linked picture before you edited and I have this to ask:
Is this black cable coming from the positive side of the battery (which should be a red cable, btw)?
Please post a pic of the wiring area above the starter where the blue welding cable attaches. I'm guessing the whole system has been hacked up.

67 Starter Solenoid is mounted too low.

Trying to get my top to work and was checking some wiring. There is a black wire that is connected to the two fuse links that run to the two blue wires on the BUS BAR.

I don't see the fusible links connected to the black wire in your picture, but they should be. That's how the top gets power.

I measured the volts on the black wire (car started) and it measured 15 volts. Is that too hot?

No. Pretty normal for alternator output when starting a car. It should settle to 13.8-14.5V after a minute or so. If it doesn't you may want to replace the regulator as it may be going out of adjustment and allowing the alternator to overcharge the battery. But don't worry about that for now.

Battery jumps up some from 12.5 when the car is running but no where near 15 volts.The fuse links are fine. But curious if there will be any ill affect further down the line. Would it set off a circuit breaker?

No. Breakers are for overloads of current and 15V compared to 14V is not significant.

I was thinking to let it be and run the fuse links off the battery side of the starter relay and keep diagnosing. But kind of weirded out that the black wire has more juice than from my battery to the starter relay.

The fusible links MUST be on the battery side of the starter solenoid! How else would the top get power? Plus, where is the passenger compartment power feed? It should be on the battery side of the solenoid also unless it is hacked in from somewhere else.

Another thing I noticed is that your starter solenoid is mounted way down the sidewall. It should be up near the top, away from that control arm opening. Here's how it looks on my 66 (67 is the same).

Starter solenoid is upside down in this pic! Ignore the orientation, I fixed it later.

First, my solenoid is upside down. Ignore.
The Black-Yellow Striped wire is from the alternator. It goes to the solenoid on the battery side.
The red wire is my temporary fusible link. Battery side of solenoid.
The big flat loop is the other fusible link. Goes to Battery side of solenoid.
Last, is the battery cable.

There should be FOUR Connections to the solenoid on the battery side.

Lastly, you don't give us any info about your problem other than you are trying to make the top work. Well, it won't work without being connected to battery.

Those two big blue wires connected to the bottom junction block feed the top system. They get 12V from a fusible link connected to the battery side of the solenoid.

The other link for the top junction is for vehicle power, like ignition, windows, headlamps, etc.

If you had an aftermarket AMP gage, then the PO really messed things up. Mine is configured as they are at the factory. Restored to original. And I know a thing or two about these cars.
Ask away, but provide pics because I can’t mentally work with wire colors without a pic.

[1967LCC]

Thanks Dan and forum. Initially, my apologies. There is a reason for the shop manual and the forum. I should have looked through both first and asked informed questions. It can just get soooooooo overwhelming for the novice and you leap out there.

What was going on:

The "low" mounted solenoid's only purpose was to use a post on it to connect the alternator black wire to the two fuse links and wires from that AMP gauge (they were blue and yellow). Nothing else connected to it. Basically PO just used the post to connect the wires together. No relay functionality whatsoever. Nothing else connected to it.

The starter relay - battery side - had the feed from the battery only. The other side of the starter relay had two red wires from the AMP gauge and the wire to the starter. So the fuse links were getting power from the alternator wire and the the AMP gauge wires closed the loop on the far side of the starter relay so the battery was getting charged. The large red wire was connected to the + of the battery.
.

AMP gauge wires

Where I am now:
I removed all the AMP gauge wires. As you stated, battery side of the starter now has:
- feed from the + of the battery
- Two fuse links
- Alternator black wire.

Removed non-functioning starter "low" relay.

Newly wired

And, as you stated, things settled down and I am getting 14+ back to the battery. So the 15 volts was just temporary. THANKS DAN!!

New reading

RE: MY ORIGINAL ISSUE: Top does not operate from key or the up/down switch (which is tested and good). I am not getting power to the switch and that is what started this adventure.

I am going through the manual and searching the forum to diagnose the issue. If you have any quick tips or forum links that would be great but I think we can stop this thread so it stays focused on the volt issue.

Thanks again!!