Instrument Panel Voltage Regulator?

[Banjo]

ok, so I've been having turn signal and fuel gauge problems off and on. I asked advise and I run searches and I think I just hit on something that I need some help about. My brand new fuel sending unit seemed to sweep great and work super at first. At times the fuel gauge will read over full (when it took nearly 13 gallons) and other times it will sweep to empty and then back up (full sweeps). The plug in clip that goes onto the back of the fuel gauge in the dash reads 1.5V with the truck running and it seems to be what i'd call "ranging" on the volt meter from 0 up to that 1.5V (roughly, it varies) maximum. I'm reading searches that say should be 5V pulse.
Also, I put continuity tester on hot lead off fuel tank sending unit while truck was running and no flashing. And when I reconnect to fuel sending unit, goes up to way over full and I know I've expended nearly 90 miles and I get about 14 mpg.
These two things alone make me tend to think IPVR is reason my fuel gauge not reading accurate on my 68 and it is sweeping and varying from dead empty to full intermittant on my drive to or from work (25 miles).
But, I also take into consideration my turn signals have been hit or miss for quite awhile despite new factory TSS and new fuzes, cleaned fuze box, chasing harness, new flashers, new bulbs, cleaning sockets, etc. Now in researching bad IPVR, seems no dash lights, and I DO have dash lights, the little fuze ok and put in all new bulbs, BUT I do tend to think even with the headlight rheostat dialed wide open the dash lights aren't quite as bright as they should be. Does any of this sound like bad IPVR (remember the diagnostics above) and does bad IPVR affect stock turn signal switch? I do have brake lights and hazard lights and headlights. My stock gauge for temp would peg hot ASAP upon hooking it up so it's not hooked up and neither is stock oil pressure gauge, I run aftermarket temp and oil gauges on a hangdown panel.
Just wondering if this IPVR is the source of my mysterious electrical problems, which to me have sounded like poor grounds.

[fordman]

from what i know the ipvr regulates power to the gauges in the instrument cluster. alt temp oil and fuel. these 4 only. i have never messed with a ipvr. from what i understand what it does is adjusts the voltage pulse to the gauges for power to them. if you suspect the ipvr is out of adjustment you could turn it one way or the other to adjust it and see what the reading gives you. however i don't think the ipvr would cause a problem of dropping in and out of the sender unit as you say is happening at times. i do think it could be grounds also. but i am not really sure of the ipvr deal and how the voltages should read properly at 5v or 1.5v. i am just not sure.

[70_F100]

5 volts is the correct voltage.

It sounds like you may have grounding issues or possibly a bad printed circuit.

[Banjo]

mine is 68 with no printed circuit board behind the instrument panel, just metal. If I understand the fuel gauge and fuel sending unit tutorial on this site correctly, both the tests I'd done (connector from IPVR to fuel sender ranging to no more than 1.5V when I think it should be 5V......and continuity tester light plugged into fuel sending unit hot wire while truck is running and zero blinking.....) at the very least I either need to attempt to "turn up" the IPVR to generate more volts coming out of it, OR I need to buy a new IPVR so at least I'd have a more accurate fuel gauge reading. I guess this will have no affect on the turn signals that just refuse to work consistently. And, I'm not blaming the stock stuff, admitting I just might not be smart enough. The older I get the more I realize how slow I am at times!

[Banjo]

And, I meant to type too while I was typing, I've grounded the heck out of this truck. but that is not to say I haven't missed something that is right in front of me. Thats the other part of getting older I find out I'm not always right! I know I wasn't ever wrong when I was 20 was I? I thank everyone for their time to read and advise it helps me think more stuff to check. Banjo.

[fordman]

maybe the ipvr needs adjusted or replaced.

[Banjo]

i have now been educated and can relay there IS a little setscrew on the backside of my stock 68 IPVR. It was under a sealer of some type that was crystalized and it popped off in chunks with an razor blade touching it. No matter how far in or out I adjusted this setscrew, it had no effect. Or is that affect. So,I will order a new IPVR and see if replacing it makes any difference. Even adjusting it had zero effect on the fuel presura gauge.
And, I checked again back at the hot connection for the fuel sending unit and the MOST I could get it to was 1.9V and it didn't even appears to be sweeping or pulsing as much.

[fordman]

effect means emotions. affect would be for our conversation. i learned that in writing class i took in school.

[70_F100]

effect means emotions. affect would be for our conversation. i learned that in writing class i took in school.

Close, but no cigar.

Effect, in this case, is a noun, meaning the result of an action.

Affect is a verb, or the action that causes the effect.

[fordman]

blame my teahcer then. those are here exact words "emotion"

[DirtyJim]

Use affect when you mean: TO INFLUENCE SOMETHING RATHER THAN CAUSE or AS A NOUN TO EXPRESS EMOTION.


it doesn't matter anyway. We all knew what you meant.