My mechanical voltage limiter has sucked for a long time, most of the time the fuel/temp gauge doesn't work. I have cleaned all the grounds and stuff when the dash was out, no difference. I also changed senders for the fuel and temp, once again no difference. I'm convinced it's the mechanical voltage limiter, so I bought a Demon IVR.

I am having trouble installing the Demon IVR. The only info I have to go on is here:

http://www.demonivr.com/Installation.html

The installation shows a '73 Valiant dash cluster, and my car is a '72 Dart and it looks very different. Also my mechanical voltage limiter has 3 'pins', not two like this shows.

I don't have wiring info, I just made educated guesses and tested it. Also I wasn't sure where to ground it, so I just used one of the mounting bolts. I assume one of the 3 'pin slots' is a ground, but i'm not sure which one.

Here is a picture hooked-up (not working), please note that I am holding the mechanical voltage limiter in-place so you can see the stock location.



Any help, ideas, or info is greatly appreciated

The black wire is ground and goes to the left prong socket in the photo (passenger side of the dash in the car).

The red wire is input +12V positive and goes to the center prong socket in the picture.

The yellow wire is the output at +5V and goes to the right prong socket in the photo (driver's side of the dash in the car).

So, the +12V comes out of the center prong socket, passes through the red wire to enter the demon unit, is converted to +5V, and leaves the unit via the yellow wire to the right prong socket where it enters the ciruitry to power your gauges.

The photo on the demon website installation page is confusing because the red wire is screwed into the middle prong socket, hiding the socket.

So, you need to move your red wire to the middle prong socket and move the black wire to the left prong socket. Your yellow wire looks to be in the right place.

Dudley is 100% correct.
Frank

_________________
Scrapple: Because a mind is a terrible thing to waste.
73 Duster - Race Car
66 Dart Wagon - DD
178" FED
82 D150
All Slant powered

OK I hooked it up correctly, I even used slot connectors so it plugs into the little slots, just like the mechanical voltage limiter.

It still isn't working...

I started the car for 5 minutes and the gauges didn't move. I attempted to do some tests with a multimeter. See the picture below:



I assume that the red wire (circled in red) is the +12v to the cluster. The black wire (circled in yellow, it's hidden) I assume is the ground. Am I correct on these assumptions?

With the car running when I put the + to the +12v and the - to the ground...and I got no reading. Then I started testing things, and when I put the - to the bolt (circled in green) I actually got a reading, around 14v or so. I have no idea if this is normal or not, I assume that if I put the - on the black wire (circled in yellow) I would get a reading...but I didn't.

How can I test to see if the Demon IVR is even working? I would like to know where to put the + and - with the multimeter, so I can test this thing, and anything else I should check on the cluster. Please help a multimeter newbie out!

EDIT:
Also, could I hook the Demon IVR's 12v input directly to the 12v input on the cluster (the wire circled in red) ?

Can I test things with the cluster out of the dash? Or is the cluster grounded to the dash via contact?

First I should apologise I supose for not registering or jumping into every forum on the net.
Someone informed me of this thread concerning our product (DeMonIVR)or the installation of it.
I get quite a few similar questions addressed to Ben@DeMonIVR.com and I answer them all but I cant associate various user names and email addresses to determine who is who. So the questions here may be answered and all is well but if not
I'm here now and egar to help

Hi Ben,
I was able to correctly hookup the DemonIVR unit, I tested the +12v and +5v wires and they seem to be functioning...however my gauges aren't.

Before I installed this DemonIVR my gauges didn't work 80-90% of the time. I replaced the temp and fuel sending units, and fixed the ground wire on the fuel sending unit, no change.

I thought the problem would be the IVR, but the gauges still aren't working. I thought the gauges might be broken, but then I realized since they worked 10-20% of the time, they must be working. I assume now that it may be a grounding issue to the cluster.

Also as far as my cluster, it's in a 71 dart. There are 6 mounting screws, and each go through the plastic area on the cluster to hold it to the dash, so I do not understand how it could be grounding through the screws.

I appreciate any help

Also, i'll try running a few ground wires from the circuit board grounding bolts, to the frame.

OK the gauges make contact through their mounting studs to the attaching nuts and the printed circuit board. Loosen or remove those nuts and clean the contact surface of the copper trace on the board. I scuff LIGHTLY with scotchbrite pad and WD-40.
Thats the most likely cause of intermittent connection since all the materials they used there change shape with temperature and at different rates too. good luck

OK--
I cleaned the grounding bolts, and attached a few grounding wires from the cluster to the frame. I cleaned the pin connections too, and everything seems to work! The temp and fuel gauge are working, but the fuel gauge is reading low and moves REALLY slow. I have nearly a full-tank of gas too, and the sending unit is brand new.

I was only able to run the car for a few minutes because it's cold outside. How long should I expect it to take for the gas gauge to 'warm-up'?

Also I tested the voltages again from the Demon IVR, i'm getting good readings.

No way to put a time frame on gauge responce since ambient temp is a factor. With a rallye gauge in my test fixture I can blow in it and cause the needle to move. My main goal with our old mopar fuel gauges is the see an empty reading before the tank runs dry.
What began as a dip stick in tank of model A Fords has evolved to "9.2 miles till empty" in digital display. Ours is what it is.
The mechanical limiters could hit the gauges with much more initial current and youdo have the option of going back to that if you wish. The DeMonIVR is returnable / refundable for any reason.

No way this DemonIVR rocks! I'm keeping it! I just need to fix a few more things.

I would hook the cluster up on a bench & test. Power up the cluster with a battery or power supply if you have one. Don't use a battery charger by itself because they are not usually filtered and may damage the regulator. Make sure you have 5v going to each of the gauges, then ground the "sensor" side of the gauge. Watch the gauge action. The gauge should peg in about 5 seconds, so don't leave the ground connected without watching the gauge. You could burn out the gauge if left connected for too long. If the gauges move all the way to the right, then they are most likely OK. If not, they are bad.

If they go all the way to the right in the above test but don't work right in the car, you may have bad connections elsewhere. With the cluster connected back in the car, you can test the gauges by disconnecting the wire from the appropriate sensor (temp or fuel) and grounding the wire. (If the cluster is mounted in the car now then do this test first.) If you had full movement in the previous test, but don't get it now, you probably have a bad connection at the firewall (for the temp gauge) or the cluster connector (for either gauge).

_________________
Chuck Rivers, Webmaster

I'm having the same problem with my '71 Dart ie: non functioning temp/fuel guage. Any tests I can do before removing instrument cluster?

Read the second paragraph of the above post.

_________________
Chuck Rivers, Webmaster