What is the correct size for bulb and socket for '72 510 tachometer?

[rosso]

I installed my factory tach and it works great but it did not have any light socket/holder or bulbs.

 

What is the best watt bulb and size of holder?

This bulb?

https://www.amazon.com/dp/B00LW7ESJE/?coliid=I34XI788YK6MM7&colid=LDUJJ7WXHAXE&psc=1&ref_=lv_ov_lig_dp_it

 

or this bulb

https://www.amazon.com/dp/B06VY1S2GQ/?coliid=I2NPWGKN2T14O7&colid=LDUJJ7WXHAXE&psc=1&ref_=lv_ov_lig_dp_it

 

There are two holes in the tach with what appear to be contacts for the holders.

 

Once again, thanks to all for any help.

[thisismatt]

I don't see any sockets or contacts in that picture. Those bulbs are the same socket but the 168 is higher wattage/brightness.

[datzenmike]

I don't see any copper traces so the socket probably has two wires, power and ground. My 710 heater controls have a push in plastic bulb holder. When pulled out it stays lit.

 

 

Here's a 620 tach with the dual wires. I think the bulbs are 3 watt.

[thisismatt]

Do you have the holders?

 

 

[datzenmike]

I think the bulbs have the brass bottom and twist in.

 

[rosso]

1 hour ago, thisismatt said:

Do you have the holders?

 

 

Nope, that is what I called socket/holder.

I don't think I have a tach wiring harness which might include the holder - at least I did not see anything when I had the clock out.

 

Edited August 28, 2021 by rosso

[thisismatt]

The pic I posted was from a NOS tach. I think you need to track down those parts, as they seem to go with the tach, not the dash harness. 

[iceman510]

I might have an extra of this subharness, or something similar.  I will check tomorrow.

[rosso]

Iceman,

Thanks, let me know what you have. I have the tach hooked up and working using new wiring for the TechnoVersion TachMatch box to convert the VG33 signal to the 4 cylinder tach. All I need is the lights. 🙂

[iceman510]

Sorry for the delay.  Here is the harness (left side) I have, not sure what it is from.  I checked and it fits in the tach holes.  One of the bulb housings has a broken tab, so it may need to be glued in or taped to stay put.  The connectors are different from my tach lighting harness, shown on the right.  The three pin connector plugs into the full tach harness.  Do you have the full tach harness? I'm sure you could make this work if you do.

 

 

Edited September 7, 2021 by iceman510

[rosso]

Thanks Iceman - great photo of the harnesses. I have the 4 cylinder factory tach all wired up and running with the V6 engine using a TachMatch converter box. All I think I need would be the bulb harness you show on the left. I am assuming there are connectors on the stock harness in my dash somewhere - I just don't recall seeing that many extra wires when I had the dash apart.

 

Is yours for sale? Shoot me a PM.

[iceman510]

The factory full tach harness plugs into the stock dash harness three-pin connector that would normally plug into the clock (if so equipped, otherwise taped to the dash harness) to access the lighting wire and ground. then the individual tach lighting harness plugs into the full tach harness also.

 

I rewrapped my harness (the right one), and I don't recall how those other two wires with the spade terminals were connected in.  Do  you currently have anything connected to the two spade terminals that come out the rear of the tach? Are they for lighting too?

[rosso]

I think I used all the wires out of the tach to connect the converter box per their instructions. The tach works fine, just no lights and there are two empty sockets on the back of the tach.

 

Cheers,

M