Would like to know if any one has seen these on a gauge before? The one is a 12v and the small button thing is on the hot wire. I am trying to see if I have 2 12v gauges, as I am going all 12 volt. Thanks To all. Tom Y
Quote from: Tom Y on February 14, 2007, 06:04:37 PM
Would like to know if any one has seen these on a gauge before? The one is a 12v and the small button thing is on the hot wire. I am trying to see if I have 2 12v gauges, as I am going all 12 volt. Thanks To all. Tom Y
Hi;
I have seen this sort of thing at a street rod/custom shop. They are used
to drop the volts from 12vdc (upgraded) to 6vdc. The purpose is to change
a early street rod systrm to 12vdc and still use the origional 6vdc gauges and
sending units etc.
Good luck
My original oil and temp gauges had that on my bus.... but it's a PD4103 12V
You could but a zener diode in series with the hot lead to lose the extra volts. Usually 14 volts at the appropriate power rating for the current draw, Jerry
Depending on the type of construction of the guage, some will read correct over a wide voltage range and others will vary as the battery charges and discharges. Sensitive types have used a voltage regulator, either internal or external for many years. There are several different ways to regulate the voltage ecconomically. If you are just trying to regulate the output of a nominal 12 volt system into a 12 volt gauge then the zener diode works fine. If you are going from 24volts to 12 you need a fairly high power zener, but a 7812 package regulator does it easily. Another approach is to make a power supply that feeds the entire dash with regulated voltage.
No I am going to all 12 volt. The reason I asked is the one is marked 12 volt but the other I can not read. So I was thinking maybe it is also, and that is why these are on them. Thanks Tom
Tom,
My 5A has those same devices on the water and fuel gauges. They seem to be step down resistors; at some point before i got it, someone built a new dash and must have used 12v gauges. It looks like 24v going in and about 14v coming out. They seem to work fine. I just replaced my fuel sending unit with the standard MCI sending unit and it reads accurately from empty to full (at least when i bench tested it).
Fred