Instrument cluster Voltage regulator

[casadejohnson]

Has anyone had any success adjusting the ICVR with the little screw on the back? I have been messing with my gauges for the past several days. Viperwolf1 was at my house last weekend and we were able to get all of my gauges functioning properly. One of the things we did was replace the ICVR with a new one from scott drake. After a couple days the gauges started to fluctuate a little and yesterday they started working only intermittently. I assumed the new ICVR was bad so I tried two others. The original that reads everything too high and another one I had from the junkyard that reads too low. Both are incorrect but at least the gages are not swinging wild. I tried adjusting the one that reads low with the little screw on the back Turning the screw seems to do nothing to adjust it. I believe I have a few more in the parts bin that I'll try but I'm guessing I'll have to buy another one. I'm planning on getting one of the electronic ones instead. I'm just a little pissy that this $30+ ICVR only worked for a few days.

 

[DJBRONCO]

I went this route a couple of years ago and mine only last a day or two as well. I gave up on it and have been just dealing without it for a while. If anyone has any suggestions I would like to hear it as well.

 

[72_EB]

Check your high beam pigtail wiring and switch. Sounds funny, but I had one working intermittently recently and I cleaned up that wiring and the ICVR and gauges starting working perfectly again. Could have been all the dash grounds I went over too, but for some reason that HB switch wiring seems to do the trick. It is an easy fix if it works. You could try it with your switch that was working intermittently.

 

[DirtDonk]

Maybe the IC type is just more sensitive to bad grounding? I suppose it's possible, but I'm assuming here too that you checked the possibilities there and added your own if it didn't seem sufficiently grounded? Maybe?
With Electro-man there to help, you shouldn't have too much more to mess with! Good local resource there I'd say.

I have messed with my original that had the screw adjuster on the back. Worked like a charm and even semi-linearly as well. Every which way I turned it resulted in the expected raising or lowering of the voltage signal and a change in the gauge readings.
Sounds like that old one you're trying is either not up to the task anymore, or you still have some connection and grounding issues to take care of.

Good luck.

Paul

 

[casadejohnson]

Maybe the IC type is just more sensitive to bad grounding? I suppose it's possible, but I'm assuming here too that you checked the possibilities there and added your own if it didn't seem sufficiently grounded? Maybe?
With Electro-man there to help, you shouldn't have too much more to mess with! Good local resource there I'd say.

I have messed with my original that had the screw adjuster on the back. Worked like a charm and even semi-linearly as well. Every which way I turned it resulted in the expected raising or lowering of the voltage signal and a change in the gauge readings.
Sounds like that old one you're trying is either not up to the task anymore, or you still have some connection and grounding issues to take care of.

Good luck.

Paul

I thought about the grounding issue. My dash is freshly painted so I pulled out the cluster and made sure I had clean paint free metal for it to ground to and also tried an additional ground wire from the cluster with no change. I only tried adjusting one of the ICVR's so I'll try adjusting the other to see if I have better luck. I think I have a couple more spares to try if I can find them.

 

[Steve83]

...also tried an additional ground wire from the cluster with no change.

From the cluster to where? With the key in RUN, put the red probe of a digital multimeter set to DCVolts on the instrument cluster rear case, and the black on various locations with bare metal on the body, t-case shifter, & pedals. Then touch the probes together and compare to your previous readings. If the cluster voltage was more than ~0.3V higher than probe-to-probe, or if it pulses, the cluster isn't grounded.

 

[casadejohnson]

From the cluster to where? With the key in RUN, put the red probe of a digital multimeter set to DCVolts on the instrument cluster rear case, and the black on various locations with bare metal on the body, t-case shifter, & pedals. Then touch the probes together and compare to your previous readings. If the cluster voltage was more than ~0.3V higher than probe-to-probe, or if it pulses, the cluster isn't grounded.

I tried a couple different options for the ground wire. I used a bolt for the door hinge and also used the bolts for the brake pedal bracket. I was able to get one of the ICVR's to adjust some. They read closer to normal but now the needles waver a little bit.

 

[DirtDonk]

When I re-wire an EB (at least with the Centech harnesses), I take one of the harness grounds, along with a short length of wire (about 12 ga or so) and screw them right into side of the dash, in the pocket where the dash, the door frame, and the windshield frame all come together.
I jumper the additional wire between the dash mount and the windshield frame to help connect everything together.
There in the corner, they're mostly out of the way and partially hidden by the rubber door seal.

Kind of kills a few birds with one wire. So to speak...
Won't help you with testing things out of the vehicle, but when it comes to being hooked up and running, it's a nice little addition I think.

Paul

 

[DirtDonk]

...Then touch the probes together and compare to your previous readings...

Steve. Is this part with them both touching the cluster still? Or separated and on their own, only touching each other?

Thanks. These are the kinds of reactions that I know exist, but never know how to read them, or what to make of them once I do.
Just not book-smart enough, but workin' on it!

Paul

 

[Steve83]

It doesn't matter what else the probes are touching (if anything) as long as they're touching each other. That step gives you a baseline reading of what that particular meter/probe combo shows for a truely dead short between the probes. It's equivalent to zeroing the meter, but you do the math in your head instead of the meter doing it.