Electrical Gurus: new voltmeter recommendation hook up to new centech harness

[Jmbronco]

I would like instructions on hooking up a new voltmeter to a new centech wire harness. Quick background: My father-in-law installed a new Centech wire harness. While it was being installed I sent my gauge cluster to get a cleaning, calibration and had a new voltmeter dropped in place of the ammeter. My question is: what is the best way to hook up the new voltmeter? I certainly don't want to ruin the gauge cluster or the centech harness so I am proceeding with extreme caution. I assume just leave the thick black continuous wire that was meant for the ammeter.


I am not great with electrical just FYI.

Thanks for any suggestions in advance,

Jeff

 

[chuck]

The Centech instructions say to wire a volt meter to the "I" terminal and the grd. That is the same wire that goes to your other gauges.

 

[DirtDonk]

...I am proceeding with extreme caution.

Excellent process! ;D

I assume just leave the thick black continuous wire that was meant for the ammeter.

Strange one Jm. The original Ford wire was the large Black one (usually with at least some of the yellow stripe showing), but Centech uses a Red wire in that position.
It's Yellow from the back of the alternator, Red from the battery (battery side of the starter relay) and Red where it would normally pass through the ammeter.

So are you sure there's a Black one still there?
Either way, like Chuck said you can connect your new voltmeter's "+" side to the 12v side of the instrument cluster voltage regulator mounted to the back of the cluster.
An alternative is to connect it direct to the accessory stud (sticks out the back of the switch) on the ignition switch. Not as clean as the IVR perhaps, but very convenient.

Got any pics of the back of your cluster by any chance? Just making sure what you've got back there, since any Black wires in a Centeh harness are usually ground wires.

Paul

 

[Jmbronco]

I'm sure the color is very important and I could be remembering incorrectly. The bronco is at my father in laws garage so I'll check later this week but it's the wire that was supposed to be for the ammeter.

Thanks for the help .

 

[chuck]

The big wire that passes through the loop on the back of the amp meter does not attach to the meter. If you don't pass it through the loop there is no harm no foul so what ever colors they are just leave them alone. Connecting to the acc stud makes the meter work with the key on ACC and Run. Going to the + side of the ICVR the meter will only work when the key is in the RUN position. Not a big deal either way.

 

[Steve83]

The other gauges only work in RUN; no real reason for the volt gauge to work in other positions.

 

[DirtDonk]

Actually, the gauges on an EB work in both RUN and ACC.

Paul

 

[Steve83]

OK Either way; connecting the voltmeter to the ICVR will make it work the same as the others, and it's the easiest place to connect.

 

[Jmbronco]

I connected the voltmeter to the I-post on one of the other gauges and ran a ground to the steering column. However, it flickers while the ignition is in the on position. I started to remove the cluster and the bottom right screw would spark.

I read somewhere that people had issues connecting a voltmeter to Voltage Regulator. they said it is better to hook up to the fuse box.

Does that sound right?

 

[chuck]

Did you connect it to the wrong side of the ICVR? Grd the volt meter to the dash. You can go to the on side(only hot when the key is on) of the fuse box if you want but that is bacicly the same wire as the I terminal but longer as the I terminal feeds the (key on) fuses.
PS after re reading you post I see that you did connect to the wrong side of the ICVR the volt meter must go to the I side of the ICVR

 

[savage]

I have a centec harness , it does say that if after market volt meter are used you have to wire it different, because stock gauges work of reduced voltage from the regulator .The instructions do talk about hooking it to the I post. I just found a 12 volt source that work when the key was in the on position.

 

[DirtDonk]

I connected the voltmeter to the I-post on one of the other gauges and ran a ground to the steering column. However, it flickers while the ignition is in the on position...

As mentioned, it has to be on the INPUT side of the instrument cluster voltage regulator. That's the "I" or "ignition" side of the regulator, NOT one of the other gauges. You can't connect it to the gauge side, or any of the other gauges themselves, or it's going to flicker.
Besides, it's not going to get an accurate system reading because that's reduced voltage after the regulator anyway. Even one of the modern ICVR's is not going to give you an accurate reading.

You said you connected it to one of the gauges? If so, there's your problem. From a stock style ICVR they are receiving a pulsed signal. So disconnect the new voltmeter from any other gauge, and simply reconnect the wire to the Centech side of the cluster ICVR.

As the others have said already, that's the same as connecting it to the fuse panel or ignition switch.

Paul