Don’t wanna, but need to pull IP to modify regulator

HWYCRZR

Old Man with a Hat
FCBO Gold Member
Joined
May 13, 2015
Messages
5,005
Reaction score
6,662
Location
Fargo, ND
Now that I am running after 12 years I already need to pull my Instrument Panel on my ‘68 Polara. As I posted on another thread I was getting some pretty large bounces on my fuel gauge and Temp gauge. Both which are fed from a voltage regulator limiting to 5 volts built into the fuel gauge.
image.jpg


I did notice the bounce when I bench tested, but wrote it off to my cheap power converter. But I don’t think that was case. Per some forum wisdom I ordered a solid-state 5 volt regulator. But it requires the old voltage regulator be taken out of play which means the IP comes out. I am going to test on my spare panel and gauges first.
image.jpg
 
And I'm glad if I have any lights on my speedometer! It's always the tools fault, isn't it?
 
Tested it on my spare gauge cluster. Seems to be working better. This one was pulsing pretty good as well.
Now I should quit procrastinating and pull it out. The only reason to pull it out is to bend the regulator and out of play.

image.jpg
image.jpg
image.jpg
 
Tested it on my spare gauge cluster. Seems to be working better. This one was pulsing pretty good as well.
Now I should quit procrastinating and pull it out. The only reason to pull it out is to bend the regulator and out of play.

View attachment 292145 View attachment 292146 View attachment 292147

This type of voltage regulator pulses normally, a set of points opens and closes to maintain the reduced voltage. They do go bad if the points fuse or start sticking. You might also want to check the ground connection for the cluster as well since a poor ground will sometimes cause erratic gauge readings.

Dave
 
Yes I even added another ground on the back of the cluster to the horn ground on the steering column. No difference. On the bench you could see it opening and closing when the gauge fluctuated. It fluctuated about 1/8-1/4 tank. Have it installed and almost back together now.
About 45 minutes to get it out.
8FD2A8E1-256F-4B34-AC73-345C8DEC29B8.jpeg
FA202265-7455-408C-B21A-A20AFD20066D.jpeg
D6925D06-B6C6-4754-A908-E044584F154B.jpeg
2276AD8D-540E-4A74-8EED-CD46FD2FDDC8.jpeg
4B301B2A-F184-4F6E-8555-8C748419E185.jpeg
5B7A8562-A97E-4B29-A256-13614FB3D228.jpeg
07E79251-8BBD-4763-A731-ED55451182C2.jpeg
 
Not as bad as I expected. The LH bezel was difficult. The new dashpad was kind of thick in the corner. Gas gauge is at least shows above 3/4. And is steady now.
image.jpg
 
I'm about to do the same thing,,both the fuel and temp are dead. I did order an electronic one,we will see.
Not looking forward to it.
 
Last edited:
That fuel gauge coil has obvious heat damage from current it carries. Might be time to rewind it. A coil is just math -matching wire size, number of turns, etc.

I had a loose battery cable that fried my temp gauge. I plan on rewinding it next Friday when I’m off work. So, I feel for you. It is not fun pulling the instrument panel out.

I did install a 7805 regulator in mine (I have a lot of electronic components laying around). I didn’t find it any better than the old school version and plan on putting my old style regulator back on.

Just what I noticed and my experiences. Hope it helps in some way.
 
I'm about to do the same thing,,both the fuel and temp are dead. I did order an electronic one,we will see.
Not looking forward to it.

Might wanna see if the printed circuit card is available for your IP, since you'll have it out. When I did my IP a few months ago (I needed "winter" weather in Florida to keep from passing out from heat) I acquired every switch, bulb and other gizmos in there to replace EVERYTHING at one time.

After all, it's not something you're looking forward to. Twice. :(
 
Might wanna see if the printed circuit card is available for your IP, since you'll have it out. When I did my IP a few months ago (I needed "winter" weather in Florida to keep from passing out from heat) I acquired every switch, bulb and other gizmos in there to replace EVERYTHING at one time.

After all, it's not something you're looking forward to. Twice. :(

I have two dash panels including circuit board. The better of the two and gauges are in my car. In the first part of the thread I did my setup and testing on my secondary IP. It works fine but as a couple people noticed the gauges have been hot. However they are still calibrated.
I had cleaned my good one and replaced all the bulbs before I put it in the car the last time. What I didn’t anticipate was my voltage regulator causing that much fluctuation. I have all good wiring and circuits now so should be good for another 50 years.
 
Back
Top