C2 Clock electrical problem

[Randy S.]

Gentlemen;
I am having electrical problems reinstalling my rebuilt clock (NOS not quartz).
Clock circuit OK before sent out for repair. The 20A courtesy lamp fuse holds until I plug in the clock.
I measured the resistance between the hot clock terminal (the one with the rubber grommet)and the case and got a dead short. I returned clock to rebuilder and he says clock works,nothing wrong with clock. he states the points have to close momentarily to charge the spring. Shouldn't I be measuring the motor winding resistance if that is correct?
I called the rebuilder back for a more detailed explaination but he had no time for a tech session as he said. I thought a $950 bill for clock and cluster would get me a little courtesy and patience but I guess not.

What should I look for next? I have 12V at clock socket and open circuit between clock hot and ground so no short on that side.

Could one of you experts give me a tech session??

Randy

[Joe R.]

Re: C2 Clock electrical problem

Randy,

Sounds like the hot +12 volts is grounding to the case of the clock. Check on the back where the black rubber goes thru the case. It may be grounding there. Other than that get your money back.

By the way, who charged you $950.00 for the cluster and clock. Did you pull this Vette out of the ocean. What gives!

Regards,

JR

[Robert C.]

Re: Sounds like you used that idiot, Roger! *NM*

[Bryan L.]

Re: C2 Clock electrical problem

Look to make sure that the clip used to hold the clock in is not touching the 12v contact on the clock. I did that a while back and kept blowing the fuse. I pulled out a mirror and carefully looked at the back, there it was.

Gotta be something simple.

BL

[Joe R.]

Re: Sounds like you used that idiot, Roger!

There are two Roger's.

Roger Scott in Florida and Roger Reid of Corvette Clock by Roger in Tennessee.
Please don't incriminate the wrong person.

JR

[Robert C.]

Re: I dn't mean the Roger in Florida

The other Roger, "clocks by Rog" , was just SO helpful to me one day! I asked a simple question about painting my gauge cluster. He says, " I can't tell you that! That's a trade secret!". I told him, "Thanks alot! and to get F....D!and walked off. That was the last time I recomended Roger, "Clocks by Rog" to anyone. This guy only helps IF he's guaranteed $.

[Dixon Green]

Re: C2 Clock electrical problem

Randy,

Is your “dead short” zero or very low resistance? The resistance of the clock coil is between 1.5 and 1.6 ohms, and may appear to be a short. For further testing, you should be able wind the clock using a 9 volt battery (e.g. #2007) by momentarily connecting the contacts.

Dixon

[Randy S.]

Re: C2 Clock electrical problem

Dixon,
I was getting 0 ohms between hot and clock case. I guess it doesn't make any difference if I measure case or ground terminal on case, same electical point right? My fiend who didn't trust my DMM took clock home and measured with his old Simpson analog and got zero ohms too. So rebuilder says nothing wrong with clock. Works on bench test.
I am really having a brain fart here!!
I agree between the two terminals I should read charging motor resistance so when points are closed, the circuit is closed, and the motor winds the spring, points open, clock runs on spring for 2 minutes and whole process starts again.

I have the old working movement. 1.8 ohm between hot and frame.

When clock is not in circuit, all courtesy lights work

I am awaiting return of clock so stay tuned.

When testing with 9v battery do I need to be concerned about polarity?
Randy

[Jack H.]

Re: C2 Clock electrical problem

(1) Yes, polarity needs to be correct for the clock to work.

(2) There is no 'motor' inside...just a set of points and a solenoid.

(3) EXPECT to see higher resistance in an old/used clock...the contact points are used/burned....

[Mike Cobine]

Instead of wondering about the clock

Open the thing up and see what is going on.

If the rebuilder won't follow through, you really have three options:

1. do it yourself
2. pay someone else to do it over
3. hire a high-priced lawyer or a mean, nasty biker who will persuade the first rebuilder to look at it again.

Me? I'd do it myself and then spread all I found out far and wide to "help" this rebuilder's reputation.

The clock is simple. As someone said, there are only a few gears, a solenoid, and a set of points. They forgot the spring.

The spring pulls the points closed. At that time, current flows and the solenoid energizes, pulling the points apart.

The spring pulls the points back, but as it does, the points connect to a "ratchet" that applies force to the gears and makes everything run. The gears stop running when the points hit the stop, which is each other, and the clock stops. However, that is when the soleoid energizes again and starts the process again.

So you are looking for a few things:

1. Short to the case or gear frame
2. Solenoid short
3. something jamming the points closed so they draw current but the solenoid can't pull them open

You can probably fix it in less time than I wrote this in.

[Mike Cobine]

Instead of wondering about the clock

Open the thing up and see what is going on.

If the rebuilder won't follow through, you really have three options:

1. do it yourself
2. pay someone else to do it over
3. hire a high-priced lawyer or a mean, nasty biker who will persuade the first rebuilder to look at it again.

Me? I'd do it myself and then spread all I found out far and wide to "help" this rebuilder's reputation.

The clock is simple. As someone said, there are only a few gears, a solenoid, and a set of points. They forgot the spring.

The spring pulls the points closed. At that time, current flows and the solenoid energizes, pulling the points apart.

The spring pulls the points back, but as it does, the points connect to a "ratchet" that applies force to the gears and makes everything run. The gears stop running when the points hit the stop, which is each other, and the clock stops. However, that is when the soleoid energizes again and starts the process again.

So you are looking for a few things:

1. Short to the case or gear frame
2. Solenoid short
3. something jamming the points closed so they draw current but the solenoid can't pull them open

You can probably fix it in less time than I wrote this in.

[Randy S.]

Re: C2 clock electrical problem Part 2

Mike,
Thanks for the tips. Thanks to all who offered suggestions.

I got clock back and it measures 1.9 ohm across terminals. Installed it last night and it works fine, no blown fuses and courtesy lamps stay lighted.

I know this clock measured zero ohms before I sent it back, My friend also measured it with his meter.

Vendor said nothing wrong with clock.....go figure. Didn't have time to explain zero ohm reading. Wanted $5 inspection fee plus freight back but changed mind. I did notice scratch marks on the tabs on the clock case but they could have been there from the first rebuild.

I am glad it was the clock and not the cluster. I don't want to have to pull that again.

I will not name the vendor but it wasn't either of the Roger's.

Thanks again to all who contributed.

Randy

[Randy S.]

Re: C2 clock electrical problem Part 2

Mike,
Thanks for the tips. Thanks to all who offered suggestions.

I got clock back and it measures 1.9 ohm across terminals. Installed it last night and it works fine, no blown fuses and courtesy lamps stay lighted.

I know this clock measured zero ohms before I sent it back, My friend also measured it with his meter.

Vendor said nothing wrong with clock.....go figure. Didn't have time to explain zero ohm reading. Wanted $5 inspection fee plus freight back but changed mind. I did notice scratch marks on the tabs on the clock case but they could have been there from the first rebuild.

I am glad it was the clock and not the cluster. I don't want to have to pull that again.

I will not name the vendor but it wasn't either of the Roger's.

Thanks again to all who contributed.

Randy