no guages in guage cluster functioning

[ddm156]

All of my guages quit working suddenly. The alt meter still sits in the middle, but the temp, fuel, and press. guages are all laying flat. I installed a centech harness years ago and they were all working properly for a long time. The fulel guage quit working first, and just within the last couple weeks the other two quit as well. Where do I start? The lights in the guage cluster all work fine.

 

[Izzy]

Talk to fallingdown. He refurbs gauges and seems to know quite a bit about them. Maybe he can help out.

http://classicbroncos.com/forums/showthread.php?t=168804

 

[347 bronco]

check the instrument voltage regulator on the back of the gauge cluster.

 

[70_Steve]

All of my guages quit working suddenly. The alt meter still sits in the middle, but the temp, fuel, and press. guages are all laying flat. I installed a centech harness years ago and they were all working properly for a long time. The fulel guage quit working first, and just within the last couple weeks the other two quit as well. Where do I start? The lights in the guage cluster all work fine.

The ammeter is actuated seperately, and directly off the output of the alternator. The fuel, temp and oil pressure gauges are powered from an Instrument Voltage Regulator (IVR), which is mounted on the bottom rear of the gauge cluster. The IVR is powered by 12Vdc and converts it to somewhat of a constant current. The output of the IVR is daisy-chained to the three gauges in the cluster. If you were to measure the output of the IVR, with an analog meter (on 0.0-20.0Vdc scale), you'd see the needle bouncing from between 3 and maybe 7 volts. On a Digital meter you'd see numbers from between 0.5 and 10.5.

Go to each of the sending units, disconnect the wire and attach it to ground. The gauge should go to the top of the scale. If any of them go to the top of the scale, then chances are the IVR is OK. If not, then check the output of the IVR. Caution, you have to be a bit of a contortionist to get at that IVR when it's mounted in place.

 

[nosaj2k]

All of my guages quit working suddenly. The alt meter still sits in the middle, but the temp, fuel, and press. guages are all laying flat. I installed a centech harness years ago and they were all working properly for a long time. The fulel guage quit working first, and just within the last couple weeks the other two quit as well. Where do I start? The lights in the guage cluster all work fine.

DDM156,

Have you resolved this issue? I too am experiencing this exact problem. I replaced the voltage regulator with a Precision Electronic Instrument Voltage Regulator from West Coast Broncos. Unfortuntately, this was not the solution. ?:? I will pick up a voltmeter and take measurements this evening as 70_Steve has suggested above.

 

[70_Steve]

I replaced the voltage regulator with a Precision Electronic Instrument Voltage Regulator from West Coast Broncos. Unfortuntately, this was not the solution. ?:? I will pick up a voltmeter and take measurements this evening as 70_Steve has suggested above.

I have no experience with that solid state IVR that WCB is selling. The old, original IVR was electromechanical, and operated much like a turn signal flasher, only faster. That's what created the pulsing. I suspect that the WCB IVR will produce a constant voltage, but I don't know exactly what that voltage is.

 

[nosaj2k]

I have no experience with that solid state IVR that WCB is selling. The old, original IVR was electromechanical, and operated much like a turn signal flasher, only faster. That's what created the pulsing. I suspect that the WCB IVR will produce a constant voltage, but I don't know exactly what that voltage is.

The IVR itself was packaged with outstanding documentation, which included the output voltage range. Unfortunately as I write, I don't have this info in front of me. I have slept since I last reviewed the material, so my recollection of the material is fuzzy at best – Déjà vu...reminds me of the college days.

 

[fallingdown]

I would be happy to take a look at it for you.

http://classicbroncos.com/forums/showthread.php?t=168804

 

[VB1975Bronco]

DDM156,

Have you resolved this issue? I too am experiencing this exact problem. I replaced the voltage regulator with a Precision Electronic Instrument Voltage Regulator from West Coast Broncos. Unfortuntately, this was not the solution. ?:? I will pick up a voltmeter and take measurements this evening as 70_Steve has suggested above.

I know that this is an old post...but I too am having the same exact problem with my 75 Bronco. I would rather not spend the $50- $60 on a new IVR if it didn't work for you.