voltmeter install

[jrw69 16]

I ordered a volt meter to replace the AMP meter from Rocketman's for my 1969 Mach 1, They said to fold back the AMP meter connections. Does this mean to fold them back at the plug where it plugs into the cluster? Wondering if anyone has done this conversion yet, and if so how did it work? Looks like it is the red and yellow on pins 16 and 17 of the plug.

Thanks

JRW69  1969 Mach 1, 351W

[Midlife 814]

Yes, remove the pins from the dash cluster and fold the connector back onto the wire and wrap in electrical tape to prevent it from shorting.  Those lines are not fused and are always hot. 

[jrw69 16]

Thanks Midlife. Will do that.

 

JRW69

[Guillaume69 150]

Hi,

I’ve done this conversion a couple years ago. Works perfect! Just make sure you state your min/max voltage values (12/15 in my case) before you send your ammeter for conversion. They’ll set it with the right resistor from scratch.

As far as adapting the printed circuit board, here’s how it looks once done. Hope this helps, along with Randy’s advice.

G

 

[jrw69 16]

Thanks for the picture, that's a big help. One question, is the 12V red wire spliced from the red going to the plug in the wire harness or from the ignition switch Just want to be sure.

Thanks

[Midlife 814]

I prefer that the red wire be hooked to the RUN-only line vice ACC, but that is just me.  Using the ACC line, your voltage will be a bit lower than battery voltage due to all of the circuitry from the battery, ignition switch, etc., so expect 10.5V with the engine not running.  Not terribly useful, IMHO.  With RUN-only lines, the voltage better reflects what is happening at the battery, albeit about 0.5 to 1.0 V lower for the same reasons.  You should see an increase in voltage from idle to significant RPM (not the RPM who posts here on the forum, though...he can be insignificant at times! *G*).

 

[jrw69 16]

Thanks again Midlife. Will probably go for a run only.

[1969_Mach1 333]

On ‎08‎/‎13‎/‎2018 at 10:07 AM, Guillaume69 said:

Hi,

I’ve done this conversion a couple years ago. Works perfect! Just make sure you state your min/max voltage values (12/15 in my case) before you send your ammeter for conversion. They’ll set it with the right resistor from scratch.

As far as adapting the printed circuit board, here’s how it looks once done. Hope this helps, along with Randy’s advice.

G

 

Can't you also disconnect (cut) the wires feeding the original ammeter a few inches before the electrical connector to the printed circuit panel?  Then put heat shrink tubing over the ends of the newly cut wires on the harness side, and wire your voltmeter using the two cut short wires sticking out of the printed circuit panel connector?  I only ask this because I have used electrical tape long enough to know it sometimes loosens and falls off.  I wouldn't have much faith in wrapping it around the bare copper terminals on the printed circuit panel.

[Midlife 814]

You mean repurposing the pins for the ammeters?  You sure can, so long as you cut the original ammeter lines and protect them from shorting.  Those dash cluster pins are now available at NPD, part 14489-10A that come with the dash cluster connector itself. 

[1969_Mach1 333]

2 hours ago, Midlife said:

You mean repurposing the pins for the ammeters?  You sure can, so long as you cut the original ammeter lines and protect them from shorting.  Those dash cluster pins are now available at NPD, part 14489-10A that come with the dash cluster connector itself. 

Yes,  it seems like a better method.

[Guillaume69 150]

There might be a « cleaner » method indeed. I simply followed RCC Innovations mounting instructions (see attached) which seemed good enough for me. It allows the conversion without altering the original underdash harness, which was important for me. You only mess with the printed circuit here (and your ammeter, of course).

Only downside of this method is now you have an additional wire (the red one) to disconnect when removing the cluster. The good thing is I never had to remove my cluster since I did that conversion. It’s been perfectly working for me as is for 4 years and 15,000 miles.

Thanks to Randy, I might add!! ;-)

G

XR7Voltmeter.pdf