Instrument cluster voltage regulator adjustment

[binder56jd]

very good info- thanks to all-jd

[rjewkes]

also i think the float needs to be checked. it may have a hole in it. also yes adusting the regulator does raise the voltage on all guages.

also maybe the little arm inside the sending unit or the float arm itself.

[N7HO]

I pulled my sending unit out of my tank and checked it, and it was in good shape and tested fine for range. So I laid it on top of the tank so it was in the full position and adjusted the IVR until the fuel gauge showed full. Now my oil pressure is back up where it should be, although the temp gauge doesn't, but that's a sending unit. My IVR was reading in the 3 volt range, as was the one on my spare cluster.

Thanks for the tip, this little problem's been bugging me ever since I got the truck.

[68F250]

Good deal!

Out of curiosity, how much did you have to adjust the regulator?

[N7HO]

I can't say exactly how much I turned the adjustment, as I had to unplug the cluster, turn the adjustment a little, plug it back in, check the gauge, and repeat untill I got the desired setting. I want to say a little over two full turns?

[Fake Name]

Is there some standard by which this can be measured? Seems kind of arbitrary to be adjusting the gauges to read the way we'd like.

fn

[N7HO]

Is there some standard by which this can be measured? Seems kind of arbitrary to be adjusting the gauges to read the way we'd like.

fn

Well, as I stated in my earlier Post, I had pulled the sending unit out and had it resting so it was in the full position. I did tests to determine that the gauge was working properly, as was the sending unit. I measured the voltage pulse at the IVR which was low. And since the Fuel, Temp, and Oil Pressure gauges which operate off the IVR were all reading low, adjust the IVR until the fuel gauge reads full. This may not be 100%, but 80% is better then 40%. And no gauge is completely accurate anyway.

[68F250]

Here's a decent article on Ford gauges, they only got a couple things wrong.

http://www.mustangandfords.com/techarticles/75259/

[Crazy_B]

My gas gauge also reads a quarter of a tank when empty can this be changed by adjusting the regulator

[Fake Name]

I've tried the ivr adjustment- no change. I have a brand-new IVR, and it had a drop of glue or some other plastic on the adjustment screw. I had to dig out the little screw, and I could not get the gauges (all reading low) to read correctly. I could get them to read LOWER, but not higher.

If I short the senders (all of them) to ground, the needles will peg to the right. Do you think I may have three bad senders- oil , temp and fuel?

fn

[Kurt Combs]

Thanks to everyone who submitted a post for this topic. I just improved my oil pressure in five minutes!

Seriously, I just replaced my thermostat and heat gauge sending unit a second time with no change in the low indication on the temperature gauge. It looked like it ran dead cold all the time. Gas gauge read 3/4 at best and oil pressure was low, but expected for an engine with 170,000 miles.

I adjusted the instrument cluster voltage regulator per this post (two turns, a little at a time) and viola, three gauges work great. Now to see if my fuel gauge is accurate when approaching empty.

So, thanks again to everyone who contributed.

Kurt

[71 LONG BED]

I need to catch up on some of these posts. I asked the same question about my fuel gauge reading 3/4 full. I didn't realize the topic was already being discussed. I can't wait to try adjusting my gauges now!!! I wasn't looking forward to diving into my gas tank. Thanks guys!

[Kurt Combs]

OOPS! After driving ten miles it seems I might have overly adjusted my gauges. I will be redoing it on Friday as temp now seems a little high and my fuel gauge is pegged. Seems like this isn't a one shot deal on a vehicle that is thirty plus years old. All though, it is great to have a temp gauge that registers higher than dead cold when the engine is warmed up.

Kurt

[Jarrad]

I spent a day getting my gas gauge working and thought I would post my method. I took the gage/sending unit out about 20 times to get it right. I found that if I adjust the voltage regulator up so the tank reads full when sending unit is at top then move sending unit to bottom the gauge reads 1/4. So The range and zero of the gauge needs to be adjusted. On the back of the gauge there are two holes with teeth visible in them. One hole closest to empty adjusts the zero point. One hole closest to full adjusts the range. Moving each adjustment toward the outside of the gauge causes the zero point to go down or the range to increase respectively. I had an empty tank so I put 10 liters of gas in and adjusted the zero to the empty mark giving me a reserve. Then I adjusted the range so that when the sending unit was in full position the needle was on full. You need to be careful with the adjustments if you go too far the gauge gets "floppy" and doesn't work. It takes some patience adjusting the voltage and the gauge but I got mine perfect. Now I will need to adjust my temperature gauge but now I can't change the voltage just the gauge.

[Mohillbilly]

I can't see any pics in Barry's post.