Bullet Bob wrote:

Ron;

Due to the inherent inaccuracy of most of the early gauges and senders I bought adjustable voltage regulators...https://www.amazon.com/slp/adjustable-voltage-regulator/qtwsc2vxgeut4yn  and used one each for TEMP, OIL, and FUEL.  Then I adjust the temp and oil to read more or less center scale under normal operating conditions.  I adjust fuel to read at the E mark when I have three or four gallons in the tank.

BB

Thanks for the suggestion BB. Happen to have any pictures laying around on your mod and install? I checked my fuel quantity the same way I did the water temp. Grounded the lead and turned on the key. I also climbed slowly to max scale. I turned it off once it passed the  F mark. The fuel quantity has always been slow and not linear in it's readings. I also checked the voltage at the unit and it was 5.01 vdc. I've never had any issues with the oil pressure gauge. It always come up to speed pretty rapidly and seems to follow engine temp and rpms and reads mid scale at cruise.
I think I might order some of those regulators as they're pretty cheap. I was wondering how you mounted them on installation. Let me know, okay. It would be nice to have gauges that operate in real time.... Do the gauges operate faster with higher voltages and what would be the max to apply to each gauge?
 

Last edited by Ron68 (7/15/2019 6:46 PM)

Bullet Bob wrote:

Ron68 wrote:

Thanks for the suggestion BB. Happen to have any pictures laying around on your mod and install? I checked my fuel quantity the same way I did the water temp. Grounded the lead and turned on the key. I also climbed slowly to max scale. I turned it off once it passed the  F mark. The fuel quantity has always been slow and not linear in it's readings. I also checked the voltage at the unit and it was 5.01 vdc. I've never had any issues with the oil pressure gauge. It always come up to speed pretty rapidly and seems to follow engine temp and rpms and reads mid scale at cruise.
I think I might order some of those regulators as they're pretty cheap. I was wondering how you mounted them on installation. Let me know, okay. It would be nice to have gauges that operate in real time.... Do the gauges operate faster with higher voltages and what would be the max to apply to each gauge?
 

The idea is not to radically increase the voltage applied to the gauge,  Just adjust it so with a good sender it will deflect to what you want for "Normal" with what ever resistance the sender is applying.  I find it doesn't take much and voltage will vary from just under 5v to just over 6v.

As for the fuel gauge, you need to adjust the sender to bottom out (+- 10 ohms) when the there is 3-4 gallons in the tank.  I have a write-up that includes templates to bench adjust the sender.  Let me know if you'd like to have it.

I found that it's best to mount the regulators on a little panel that's accessable from under the dash.  That way there's no need to pull the cluster to make the adjustments.

BB

I'm assuming that you mounted them on a circuit board and ran wires from the board to each gauge? Also, if you could send me that template, I'd like to get a look at it. I'll pm you my email addy, if you don't already have it. Thanks for the help. I ordered those vr's from Amazon.
 

Bob I need this info too! where is the write and install info!! ?

RV6 wrote:

Bolted to Floor wrote:

RV6 wrote:

Gary, Where did you dig this up? It matches what I was seeing with my car at the 230 mark.
 

I grabbed this a couple of years ago off the vintage mustang forum. I have found it dead on, hence the reason I keep it.
 

Okay, that is great chart, but where can I find the right sender unit that has those resistance values??? Everywhere I check, I always get the same sensor. I have bought two new ones, both listed as applicable to a 68 with a V8 12v system. They both read 350 ohms when cold and about 33 ohms when hot in boiling water. Where do you get one that reads 10/78?? Even the one I have installed reads the same as the new ones. I am using a Fluke digital meter to read them.
 

Bolted to Floor wrote:

Ron68 wrote:

RV6 wrote:

I grabbed this a couple of years ago off the vintage mustang forum. I have found it dead on, hence the reason I keep it.
 

Okay, that is great chart, but where can I find the right sender unit that has those resistance values??? Everywhere I check, I always get the same sensor. I have bought two new ones, both listed as applicable to a 68 with a V8 12v system. They both read 350 ohms when cold and about 33 ohms when hot in boiling water. Where do you get one that reads 10/78?? Even the one I have installed reads the same as the new ones. I am using a Fluke digital meter to read them.
 

Ron, I was more interested in how the actual temperatures lined up with the needle position. I have never checked the Ohms of the sender. All of my gauges went to Rocketman Classic Cougar for calibration. Once installed, the temp was showing a screwy reading so I bought a new sender. My problem was solved. According to Oreillys, your 6 cylinder car and my V-8 car both used the same sender. What do you know about the gauge??
 

The gauge is original to the car. I have an O'reilly's sender installed and a new one I bought from them. Same resistance readings. The sender I have installed was new when I installed the 351W back in 2008, but it has the same readings as a new one. I got some small voltage regulators suggested by Bullet Bob and I plan on wiring them in as he suggested to adjust my individual gauges to optimal readings.