Author Topic: Speedomter speed minder. 1969  (Read 8613 times)

WaltZ

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Speedomter speed minder. 1969
« on: May 13, 2020, 03:14:14 PM »
I have the original 120 mph speed minder unit and with a continuity tester everything has checked out. Only the speedometer is an oer.
all wiring is correct.
I added a ground to the speedo base (maybe this is the issue) but does not work without it grounded.
Tried a resistor in line, but acts the same.
When it contacts to buzz, the tach goes crazy.
Also, the copper contact on the speedometer needle heats up to a glow.
worked in on my desk with a 9 volt battery and works and does not seem to over heat the copper contact wire.
Also replaced the voltage regulator with the correct oer made in USA.
I am replacing the 70 amp alternator with a properly coded 37 amp as soon as it is delivered, could this be it.
Driving me crazy!
thanks in advance
« Last Edit: May 13, 2020, 04:08:52 PM by WaltZ »

WaltZ

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Re: 1969 Speedometer Speed Minder "Help"
« Reply #1 on: May 15, 2020, 02:38:40 PM »
Any ideas out there?

jvb6648

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Re: Speedomter speed minder. 1969
« Reply #2 on: May 15, 2020, 03:02:55 PM »
With the ground wire attached do you still get the crazy tach and hot contact? I believe there should be a separate ground wire from the instrument cluster. A star washer under the ground wire will make a better connection.
Jim
68 Z/28

WaltZ

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Re: Speedomter speed minder. 1969
« Reply #3 on: May 15, 2020, 03:51:32 PM »
yes, crazy tach and hot contact.  it's attached with excellent continuity with star washers.

 

KurtS

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Re: Speedomter speed minder. 1969
« Reply #4 on: May 15, 2020, 06:51:23 PM »
With the engine on, what's the voltage? That will tell you if the alternator or volt reg is an issue.
Kurt S
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WaltZ

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Re: Speedomter speed minder. 1969
« Reply #5 on: May 15, 2020, 07:01:59 PM »
betwenn 12 and 13 volts

camaronut

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Re: Speedomter speed minder. 1969
« Reply #6 on: May 15, 2020, 11:27:16 PM »
Are you sure that the wire from the tach - going to the coil is on the right terminal?  I'm pretty sure it should go to the negative terminal.

I'm thinking that's your problem....ground loop...
« Last Edit: May 15, 2020, 11:56:20 PM by camaronut »

KurtS

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Re: Speedomter speed minder. 1969
« Reply #7 on: May 16, 2020, 03:17:00 AM »
That's good. Changing the alternator and/or regulator won't change anything....
Kurt S
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firstgenaddict

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Re: Speedomter speed minder. 1969
« Reply #8 on: May 17, 2020, 03:44:45 PM »
YES the tach wire goes to the negative side of the coil on a 69 Camaro.
here is a schematic Kurt posted a few years ago on Camaros.net which he attributes ED B as the creator.


James
Collectin' Camaro's since "Only Rednecks drove them"
Current caretaker of 1971 LT1's - 11130 and 21783 Check out the Black 69 RS/Z28 45k mile Survivor and the Lemans Blue 69 Z 10D frame off...
https://plus.google.com/photos/112392262205377424364/albums?banner=pwa

jvb6648

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Re: Speedomter speed minder. 1969
« Reply #9 on: May 17, 2020, 05:30:58 PM »
Sounds like the buzzer may be grounding through the tach. Is it an in dash tach or separate tach mounted on the column or someplace else? Where is the buzzer supposed to ground?
Jim
68 Z/28

WaltZ

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Re: Speedomter speed minder. 1969
« Reply #10 on: May 18, 2020, 01:42:25 PM »
I'll give schematic a try and will let you know.
In dash oer tach
factory wiring

 thanks for the info

firstgenaddict

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Re: Speedomter speed minder. 1969
« Reply #11 on: May 18, 2020, 04:30:20 PM »
Sounds like the buzzer may be grounding through the tach. Is it an in dash tach or separate tach mounted on the column or someplace else? Where is the buzzer supposed to ground?
Yea that is what I was trying to determine... where the grounding was occurring, because there is a direct ground which is causing the contact (point of highest resistance) to heat up.
Maybe the resistance is too high for the buzzer to get enough current or the buzzer requires more current -
Who swapped the original speedminder stuff onto your replacement speedo?
OR do you have a repro speedo and speed minder mechanism as ONE unit?
And everything else is original?
IF you have repro speedo speedminder needle contacts etc...
DID you fully service your original parts? FULLY clean ANY contacting points for harness connections?
Did you ensure the plugs are actually contacting with zero ohms resistance?
The tangs on the bottom of the highram?
The packard terminals, did you remove the metal terminal ends from the harness plugs and use a fine wire brush and clean them and lube them with connection compound?
The resistance (current load) BEFORE getting to the highram may be too much for the circuit... There is NO DOUBT in my mind that a reproduction contact is going to be inferior by orders of magnitude to the original delco component. 


For cleaning original harnesses...
I pin a harness down to a 6 foot long 2 foot wide piece of plywood with a sheet of paper which I draw out all the connections - label all the harness ends and wire colors, then unwrap the harness, clean the connections, and repair any damage, prior to rewrapping in harness wrap and installing the plastic ends which I run through the dishwasher a few times (in the utensil baskets). 
I made a tool to remove the terminals from the plastic plugs using a piece of stainless tig wire which I hammered flat and then filed to the correct width. I made a loop on mine to wrap around my thumb so I can use both hands to manipulate the plugs under a dash etc when fixing wiring problems on "restored" cars... Sorting out wiring and glass fitment issues on "professional restorations" could be a FULL time job if I wanted it...   



 
« Last Edit: May 18, 2020, 04:58:21 PM by firstgenaddict »
James
Collectin' Camaro's since "Only Rednecks drove them"
Current caretaker of 1971 LT1's - 11130 and 21783 Check out the Black 69 RS/Z28 45k mile Survivor and the Lemans Blue 69 Z 10D frame off...
https://plus.google.com/photos/112392262205377424364/albums?banner=pwa

WaltZ

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Re: Speedomter speed minder. 1969
« Reply #12 on: May 19, 2020, 12:54:44 PM »
all terminals and wiring checked.
buzzer cleaned and contacts filed and ohm tested.
the only piece changed from original kit is the speedometer which I stated is an oer.
will recheck and try again this weekend.
thanks

firstgenaddict

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Re: Speedomter speed minder. 1969
« Reply #13 on: May 19, 2020, 04:29:48 PM »
The speedometer and SPEEDMINDER come together from OER correct?
OR did you put an original 1969 speedminder on a OER speedometer?
IF the speedminder is OER then I suspect that is your problem.
Either get another OER speedminder and try it or find a GM original speedminder speedometer.
 
James
Collectin' Camaro's since "Only Rednecks drove them"
Current caretaker of 1971 LT1's - 11130 and 21783 Check out the Black 69 RS/Z28 45k mile Survivor and the Lemans Blue 69 Z 10D frame off...
https://plus.google.com/photos/112392262205377424364/albums?banner=pwa

WaltZ

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Re: Speedomter speed minder. 1969
« Reply #14 on: May 19, 2020, 06:20:38 PM »
Only the speedometer is oer,,,,,,  the rest is factory and tested.

The speedometer and SPEEDMINDER come together from OER correct?...  No such kit available, parts sold seperately
 
OR did you put an original 1969 speedminder on a OER speedometer?.... YES I did

 

anything