w-30dreamin

Hi,
I have done a search here on the board and have read all the threads concerning rally pac gauges.Unfortunately I am not very good when it comes to electrical items,I am very nervous about doing something wrong and frying something out,still a little confused about this swap.This stuff was to pricey to take chances with so I am turning to the experts here.

I have an oem factory rally gauge set with the factory shielded wire and factory sending units that are needed.I can install the gauges and sending units no problem.

1)Can someone please give me a good step by step walk thru of where and or how all the wiring needs to be hooked up?

2)I have a Pertronix under cap conversion installed in the stock distributor .Is this compatible with the factory tach or will I need to reinstall points? I have contacted Pertronix and they have no idea if they are compatible.

The car is a 1971 Cutlass S with standard dummy lights and clock in place now.

thank you,
signed,
nervous and confused in NW Indiana

knighthawk

depends on who you buy the gages from, they should tell you how to connect them the info is also in the threads here, if you did the 'search'' on installing ralley pak gages. this is how I did mine

w-30dreamin

All my gauges and parts are original used oem factory parts in good condition.
Most of the info I have read thru my search refer to The Parts Place aftermarket gauges.I am not sure if there is any difference between aftermarket and factory original.
Could not find any info regarding the compatibility between the Pertronix and the factory tach.

thank you

knighthawk

I got Pertronics in my '69, just hook up the tack like it says,,,,1 wire to -- side of the coil

My442

Here you go.

My442

I have a Pertronix III with the factory rally pack - no issues.

Be aware that the Pertronix needs a full 12 volts to work properly. You need to run a 12 volt supply from the fuse box (key activated), or replace the resistor wire in the engine harness.

What I did was have a new engine harness made by M&H, and they put in the "HEI" modification that has a regular wire that goes to the coil.

w-30dreamin

Thanks for the info Knighthawk and My442,unfortunately I still have questions.
Here is a pic of the back of the tach.
1)Is the spade terminal on the back of the tach for the
lead running to the clock?
2)Where does the eyelet lead that is on the shielded wire
hook up?
3)What size fuse should be installed in the inline fuse
holder?
4)What hooks into the grey wire connecter coming off
the back of the tach?
DSC03715.jpg

On the plug in assembly My442 shows there are 7 wires,on the spare from a non rally gauge set up I have,there are 8 wires.
1) What happens with the light green(olive green) wire(first wire from left) in my pic?
2) In My442's pic,from left, is the first wire black or dark brown?
3) If you guys can answer question #2,I'll know the
other wire is what would be sixth from left,either black
or dark brown.

DSC03717.jpg

thank you

Lady72nRob71

w-30dreamin

Rob,thank you so much for answering my first batch of 4 questions. I am clear on those now.

I understand the wires in the connector get rearranged and because of one of your past threads I know how to do that.
I see you added additional info while I was typing this reply,I'm going back to reference your thread.

Thank you

w-30dreamin

Ok...thanks much,I should have no problem now.Referenced your thread again for the upteen hundredth time.
My eyes are not what they use to be,now I see the wire I was referring to as light or olive green is actually the grey wire.

thank you so much!

Del70

How to test a tach- Just need to confirm -The Brown wire is the tach feed. The gray is lights, and the spade connector is the clock. The ground is the case to the dash.

The service book says to test a tach, hook a test wire between the terminal of the tachometer then to the negative side of the coil, and another wire to the tach ground…I assume the terminal of the tach is the brown wire, and the ground is the case..just want to be sure. Sound correct? Thanks

Lady72nRob71

Sounds like you have it!

stevengerard

old thread but I need some help. I bought a new tach harness as this is just another thing the body shop messed up that I am trying to repair.

1) The loop on the braided wire in the picture above - does that go to the center stud with the nut on the back of the tach?

2) Where does the other end of that braided wire go, mine has no end on it just looks like it is wrapped around the other end of the brown wire that gets attached to the negative side of the coil.

dfire25

The loop on the braided line get connected to ground and the brown wire connects to the tach terminal on the back of the tach. I used the ground strap just to the left of the gauge for the braided loop.

The other end on the braided wire should be attached to the terminal that's connected to the coil.

stevengerard

Thanks, I'll give that a try.

stevengerard

I decided to check the hardtop - seems like it was never touched back there. Shielded wire was attached to a bolt behind the dashboard passenger side of the tach just above the AC/Heat control switches

dfire25

That's good to know. If that's the factory position and its never been touched that's probably the right spot.

They didn't show where to connect it to on the directions, so I just assumed it went to ground and hooked it up on the ground strap

I'll check it out when I get a chance. Maybe I'll change it or just leave it as is.