New Volt Gauge reading high at times.

Help Support 7173Mustangs.com:

Joined
Sep 12, 2015
Messages
5,772
Reaction score
880
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.

 

midlife

Shorts checker
Joined
Jan 24, 2012
Messages
4,079
Reaction score
496
Location
Tucson, AZ
My Car
No Mustangs at the moment.
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.

 
Joined
Sep 12, 2015
Messages
5,772
Reaction score
880
Location
SW Ontario
My Car
1971 Mustang Mach 1, M code, 4 speed.
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.

 

Don C

Fords Forever
Joined
Jan 1, 2012
Messages
8,108
Reaction score
865
Location
Springfield, OR
My Car
1971 Mustang Sportroof M code
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.

 

Don C

Fords Forever
Joined
Jan 1, 2012
Messages
8,108
Reaction score
865
Location
Springfield, OR
My Car
1971 Mustang Sportroof M code
A Motorcraft electronic one is all I use. If you want it to look original you can replace the cover with your period correct cover.

 

73pony

VIP Members
Joined
Jul 6, 2015
Messages
4,241
Reaction score
92
Location
Iowa
My Car
1973 Mustang Grande 351C 2v
A Motorcraft electronic one is all I use. If you want it to look original you can replace the cover with your period correct cover.
+1 on the motorcraft electronic regulator.

 
Joined
Feb 24, 2014
Messages
2,850
Reaction score
203
Location
Oxford Ms
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.

 

NOT A T5

VIP Members
Joined
Jul 19, 2016
Messages
1,949
Reaction score
62
Location
Omaha, NE
My Car
1971 Mustang Convertible
+1 on electronic regulators, put it inside your "original" cover. Any 71-73 Mustang is too nice to have a battery boil over! Ask me how I found out!

 

SteveO_71

Well-known member
Joined
Apr 8, 2015
Messages
476
Reaction score
42
Location
Upstate NY
My Car
71 Mach 1, 351c 4v, C6 trans, grabber blue with white interior
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

 

Bill73Ragtop

Long time vintage mustang hobbyist
Joined
Apr 19, 2011
Messages
1,419
Reaction score
32
Location
Buffalo, NY
My Car
1969 Convertible Restomod enhanced.
former owner (25 yrs) of 1973 Convertible, 351c, A/C, RA
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.....

 

SteveO_71

Well-known member
Joined
Apr 8, 2015
Messages
476
Reaction score
42
Location
Upstate NY
My Car
71 Mach 1, 351c 4v, C6 trans, grabber blue with white interior
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:

Twins

VIP Members
Joined
Aug 8, 2014
Messages
374
Reaction score
5
Location
New York
My Car
1973 Q code Mac 1
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.
 

SteveO_71

Well-known member
Joined
Apr 8, 2015
Messages
476
Reaction score
42
Location
Upstate NY
My Car
71 Mach 1, 351c 4v, C6 trans, grabber blue with white interior
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.

 
Joined
Sep 12, 2015
Messages
5,772
Reaction score
880
Location
SW Ontario
My Car
1971 Mustang Mach 1, M code, 4 speed.
A Motorcraft electronic one is all I use. If you want it to look original you can replace the cover with your period correct cover.
 Thanks Don and others. I guess I'll go shopping for the Motorcraft. Thanks for the tip.

Geoff.

 
Joined
Sep 12, 2015
Messages
5,772
Reaction score
880
Location
SW Ontario
My Car
1971 Mustang Mach 1, M code, 4 speed.
 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.

 

Twins

VIP Members
Joined
Aug 8, 2014
Messages
374
Reaction score
5
Location
New York
My Car
1973 Q code Mac 1
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

 
Joined
Sep 12, 2015
Messages
5,772
Reaction score
880
Location
SW Ontario
My Car
1971 Mustang Mach 1, M code, 4 speed.
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.

 
Top