New Volt Gauge reading high at times.

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Sep 12, 2015
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Location
SW Ontario
My Car
1971 Mustang Mach 1, M code, 4 speed.
Question for Midlife...……. or anyone else with extensive electrical knowledge.

As most know, I recently installed a set of Bosch aftermarket gauges in my Mach 1. I'm absolutely loving having the Temp, Oil and Volts right there in front of me, well to the right side actually!!

On the return trip from the Ford Mustang Memories car show and the longest run my car has been on since installing said gauges, and whilst waiting at the border, I noticed that the Volt gauge was reading quite a bit higher than the usual 14 volts, engine running. It went up to just above 15V. The temp gauge was a tad higher than normal also, but that was not surprising sitting on a hot day. My feeling is that the 14 gauge wire I used to connect the volt gauge might be a bit too light and it was over heating causing the higher than usual reading.

As my car does not have any ACC terminal at the fuse block, I had connected to the wire I installed for my Rocketman tach conversion, basically because it was there and an available switched 12v wire. Normally, I don't see this higher reading. My voltage regulator is new(ish) so that's should not be the reason although possible I guess. I'm sure that the very hot weather has an impact on many things, this being one of them.

So, what's the opinion as to cause?

Geoff.

 
Voltage regulator is no longer regulating. The reason why your temp gauge was a tad higher than normal is that the input voltage was also a bit higher than normal.

 
Voltage regulator is no longer regulating.  The reason why your temp gauge was a tad higher than normal is that the input voltage was also a bit higher than normal.
 I had a sneaky feeling it might be something like that. Damn repops!! Any suggestions as to what and where to get a GOOD one? Would this still be the case when under normal outside temps, it seems pretty close on the temp gauge, about 190 with a 190 stat and 14 Volts when running, 12 not running?

 At least I won't have to go pull the dash apart again to replace a wire.

Thanks very much for your valued input.

Geoff.

 
Voltage regulator is no longer regulating.  The reason why your temp gauge was a tad higher than normal is that the input voltage was also a bit higher than normal.
+1

14 gauge wire is plenty big, an analog voltmeter draws very little current. 16 or 18 gauge is fine for them.

 
Geoff, your car is to nice to risk a battery boil over and mess up all that detail work you have done. It's just a matter of when it's going to happen and not if it will happen.

Use Ford FOPZ-10316A  or Motorcraft GR-540-B. Ford replaced all mechanical regulators in the 80's with the electronic style. So anything you see with the Autolite/Motorcraft tall covers (especially the Concourse units ) are licensed by Ford but are NOT genuine Ford parts . Most of those are the old point/contact style made in China. 

If you want the "Look" you can always switch the old style cover to the new regulator.

 
Voltage regulator is no longer regulating.  The reason why your temp gauge was a tad higher than normal is that the input voltage was also a bit higher than normal.
 I had a sneaky feeling it might be something like that. Damn repops!! Any suggestions as to what and where to get a GOOD one? Would this still be the case when under normal outside temps, it seems pretty close on the temp gauge, about 190 with a 190 stat and 14 Volts when running, 12 not running?

 At least I won't have to go pull the dash apart again to replace a wire.

Thanks very much for your valued input.

Geoff.
My voltage was doing the same thing last week and replaced the VR to bring it back to 14.2v.

If you dont want to buy a generic and replace the cover route, VCM has a solid state one with correct covers. They also have a solid state instrument panel VR.

For my car it was.....  http://www.virginiaclassicmustang.com/Voltage-Regulator-70-71-Autolite-Stamping-DOAF-P1330.aspx

 
So the new gauges just paid for themselves.... as a problem was indicated in the readout and you paid attention to it before it got really expensive.....

 
This as happened a couple of times to me. Sounds like its time for me to do the Ammeter to volt meter conversion from RCCI!

 
Last edited by a moderator:
Voltage regulator is no longer regulating.  The reason why your temp gauge was a tad higher than normal is that the input voltage was also a bit higher than normal.
 I had a sneaky feeling it might be something like that. Damn repops!! Any suggestions as to what and where to get a GOOD one? Would this still be the case when under normal outside temps, it seems pretty close on the temp gauge, about 190 with a 190 stat and 14 Volts when running, 12 not running?

 At least I won't have to go pull the dash apart again to replace a wire.

Thanks very much for your valued input.

Geoff.
My voltage was doing the same thing last week and replaced the VR to bring it back to 14.2v.

If you dont want to buy a generic and replace the cover route, VCM has a solid state one with correct covers. They also have a solid state instrument panel VR.

For my car it was.....  http://www.virginiaclassicmustang.com/Voltage-Regulator-70-71-Autolite-Stamping-DOAF-P1330.aspx

I have a generic regulator but it is solid state.  For the sake of looks I thought maybe I would pick up the correct looking one.

It's funny but when I went to VR's website - for yours they indicate it is a solid state regulator.  When I went to the one for my car (its a 73) they talk about the part but that one description is left out.  I wonder if their 73 is the "old" style or there is just an oversight in the description of the part.  I'll have to call them if I want to go forward with it.
 
My part for 71 originally didnt have the "solid state" description and I sent an email to VCM with the question to verify. Michelle from VCM stated that all the VR's they carry are now solid state. 

The description for mine is now changed so it might be an oversight that the description for the 73's has not been updated yet.

 
 I had a sneaky feeling it might be something like that. Damn repops!! Any suggestions as to what and where to get a GOOD one? Would this still be the case when under normal outside temps, it seems pretty close on the temp gauge, about 190 with a 190 stat and 14 Volts when running, 12 not running?

 At least I won't have to go pull the dash apart again to replace a wire.

Thanks very much for your valued input.

Geoff.
My voltage was doing the same thing last week and replaced the VR to bring it back to 14.2v.

If you dont want to buy a generic and replace the cover route, VCM has a solid state one with correct covers. They also have a solid state instrument panel VR.

For my car it was.....  http://www.virginiaclassicmustang.com/Voltage-Regulator-70-71-Autolite-Stamping-DOAF-P1330.aspx

I have a generic regulator but it is solid state.  For the sake of looks I thought maybe I would pick up the correct looking one.

It's funny but when I went to VR's website - for yours they indicate it is a solid state regulator.  When I went to the one for my car (its a 73) they talk about the part but that one description is left out.  I wonder if their 73 is the "old" style or there is just an oversight in the description of the part.  I'll have to call them if I want to go forward with it.
 Ok thanks for the link. That looks good, so now the question, VCM or Motorcraft??

 Sorry guys, I had to ask.

The reason this got changed about 3 years ago was because of VR failure and battery boil over, new battery as well. Fortunately with no ill effects to the battery. And yes, it made a right mess of the engine compartment. I poured baking soda and warm water all over and while it stopped the acid, it left a white film over everything. This was a major reason to redo the entire engine and bay. Took what seemed like forever to make sure all the acid was killed and removed.

By the way, the car took a Best Muscle Car trophy at a local show on the weekend.

Thanks for all the help to you all,

Geoff.

 
My part for 71 originally didnt have the "solid state" description and I sent an email to VCM with the question to verify. Michelle from VCM stated that all the VR's they carry are now solid state. 

The description for mine is now changed so it might be an oversight that the description for the 73's has not been updated yet.
Thanks Steve. Thats interesting. Ill bet she didnt realize it.
Sent from my SM-G935V using Tapatalk

 
Voltage regulator is no longer regulating.  The reason why your temp gauge was a tad higher than normal is that the input voltage was also a bit higher than normal.
 I had a sneaky feeling it might be something like that. Damn repops!! Any suggestions as to what and where to get a GOOD one? Would this still be the case when under normal outside temps, it seems pretty close on the temp gauge, about 190 with a 190 stat and 14 Volts when running, 12 not running?

 At least I won't have to go pull the dash apart again to replace a wire.

Thanks very much for your valued input.

Geoff.
My voltage was doing the same thing last week and replaced the VR to bring it back to 14.2v.

If you dont want to buy a generic and replace the cover route, VCM has a solid state one with correct covers. They also have a solid state instrument panel VR.

For my car it was.....  http://www.virginiaclassicmustang.com/Voltage-Regulator-70-71-Autolite-Stamping-DOAF-P1330.aspx
 Just ordered one from VCM. Thanks

Geoff.

 
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