Yet another dead gauge thread

[1buckeyefan1]

I've been debugging my gauge cluster all day and am at wits end.. I just got my explorer swap on the road and almost immediately lost my fuel, temp, and oil pressure gauges.

When I first started it up, my fuel gauge was good, and the coolant/oil gauges pegged. Then they went dead and I can't seem to get them working again.

I've tested/swapped my IVR and it seems to be working properly. 12v at the lead, pulsating on the outbound, tested while in the cluster, grounded.

My oil will go to about 10 and coolant to 120 and pretty much stop. Fuel doesn't budge

I'm pretty sure the IVR is doing its job. It's a new Tom's gauge cluster. I had a similar issue initially when i tried using a new Dennis Carpenter IVR and re-using my original IVR seemed to solve it at the time. But whatever gremlin I suppressed is back again.

I also ran a new ground wire to the back of the cluster, using the IVR screw.

Any thoughts on what to test next?

 

[DirtDonk]

What sending units are you using? The ones for the explorer computer, or the ones original to a bronco?

 

[1buckeyefan1]

What sending units are you using? The ones for the explorer computer, or the ones original to a bronco?

For coolant/oil - Original for bronco. replaced with new ones and was getting good readings from external gauges.

For fuel - i went with the vertical slide unit that I think Nick did a group buy on a few years back. Seemed to work pretty well at first, but now a zombie.

Has to be some sort of issue with a ground or gauges. Back at it today if anyone has an idea of what to test next.

 

[Speedrdr]

Almost sounds like a dead short that’s killing/killed some of the gauges, but that would be too obvious and I’d bet you checked for that. That’s all I can thnk of.

Randy

 

[DirtDonk]

Was the vehicle painted recently?
Usually that becomes a problem with grounding the dash, but you should have cured any possibility of that with your direct ground to the cluster. So I’m not quite sure where to look next.
Still thinking on it though…

 

[1buckeyefan1]

Was the vehicle painted recently?
Usually that becomes a problem with grounding the dash, but you should have cured any possibility of that with your direct ground to the cluster. So I’m not quite sure where to look next.
Still thinking on it though…

yep, the dash was painted recently. I thought for sure i'd fix it by running a ground wire directly from the battery post to the rear of the IVR bolt. No luck.

I did ground a few of the gauges out and can get them to peg. But for example, the oil pressure gauge will go to 10 when running. It has life, but seems 'muted'

I'm pretty sure when i got it first started up, something moved/changed. I was tucking away the wires for the lights, etc.. but no blown fuses so I don't have any visible evidence of a dead short.

 

[1buckeyefan1]

yep, the dash was painted recently. I thought for sure i'd fix it by running a ground wire directly from the battery post to the rear of the IVR bolt. No luck.

I did ground a few of the gauges out and can get them to peg. But for example, the oil pressure gauge will go to 10 when running. It has life, but seems 'muted'

I'm pretty sure when i got it first started up, something moved/changed. I was tucking away the wires for the lights, etc.. but no blown fuses so I don't have any visible evidence of a dead short.

So I hooked up my old gauge cluster, IVR and grounded it. Oil pressure is working fine. So it's definitely related to something in the dash.

 

[Speedrdr]

You should KNOW that the problem is gonna be in the least accessible area and require assuming the least comfortable position to work on. You know, Murphy’s Law??

Randy

 

[1buckeyefan1]

Almost sounds like a dead short that’s killing/killed some of the gauges, but that would be too obvious and I’d bet you checked for that. That’s all I can thnk of.

Randy

I think this might be the answer. As I was messing with loosening/tightening the gauge cluster from the dash, I got them to come back to life for a short bit, then got sparks near the ignition. Once I let my hand off the allen wrench did it quit. I think I was grounding the dash to the earth. Now to figure out the source of the short?

 

[1buckeyefan1]

So here's where I made it today. If I loosen up the gauge cluster from the dash, i can get a good reading with key on. I attached a picture of the fuel gauge with key on. Once I press it up to the dash, it starts going down. Push it out of dash and I get a good reading.

 

[cldonley]

So here's where I made it today. If I loosen up the gauge cluster from the dash, i can get a good reading with key on. I attached a picture of the fuel gauge with key on. Once I press it up to the dash, it starts going down. Push it out of dash and I get a good reading.

Sounds like there is something shorted inside your cluster that grounds out when you firmly anchor it to the dash. Maybe disconnect one gauge at a time and see if you can isolate a faulty gauge? Or look behind the instrument panel for a wire caught between the cluster and the dash. Maybe it'll be something super simple...

 

[staleb00]

Reviving this dead thread. Having similar issues as above so looking for some guidance. Just updated my wiring harness to a painless and have an explorer swap. Painted the dash as well. All the gauges were working prior to the harness change and repainted dash. Brand new IVR as well. I have 12v going into IVR and a constant 5v on the female side. Have a clean ground in the dash and ran a second ground wire from the firewall where I grounded the c115 to that same bolt in the dash for the painless harness.

Temp and oil read 120 and 10 respectively. Fuel reads 3/4 full. Weird thing is when I unscrew the the top left gauge cluster screw as if I were remove the cluster from the dash, everything goes to zero. Makes me think it’s something with the gauges but have no idea.

 

[DirtDonk]

Did you get this all sorted yet staleb?

Painted the dash as well.

That's usually the start of electrical issues.

All the gauges were working prior to the harness change and repainted dash. Brand new IVR as well.

Sounds like you have a stock gauge cluster then? Did you happen to paint the housing as well as the dash?
Old IVR still handy by any chance? Just to swap things around to see what's going on.

I have 12v going into IVR and a constant 5v on the female side.

Sounds good so far.

Have a clean ground in the dash

What does that mean exactly?

and ran a second ground wire from the firewall where I grounded the c115 to that same bolt in the dash for the painless harness.

Good practice. Where exactly did you attach that to the dash panel?

Temp and oil read 120 and 10 respectively.

Fuel reads 3/4 full.

Factory gauges still, but what about the sending units? Are they Explorer based, or original Bronco based?
You need both types if you're going to run the Explorer EFI and use older gauges that read from a different ohm range.
The fuel sender is finicky however, and 3/4 full seems to be the normal max.

Do you know how much fuel is in the tank exactly?
Have you verified accuracy with an external thermometer?
Can you get a mechanical gauge in the oil system at least temporarily so that you know what's going on?
Is this a newly rebuilt engine? Original Bronco? Original Explorer?

Weird thing is when I unscrew the the top left gauge cluster screw as if I were remove the cluster from the dash, everything goes to zero. Makes me think it’s something with the gauges but have no idea

Well, I could say that it's "something with the gauges" but what it sounds like from here is "something with the grounding" instead.

Attach a jumper ground directly to the screw holding the IVR to the cluster. Attach a ground strap/wire to the dash, and to that bolt you have on the firewall. Or is that what you already have?
Forget the fuel at this point, because it might not be able to send an accurate signal at this point. Yet..
Is it a new sending unit?
Once you get the thing fully grounded and working with the other two gauges, then pull the fuel sender and tweak it until the gauge reads to your satisfaction.

Good luck. Can't help but think it's still a grounding issue at this point.

Paul

 

[staleb00]

Did you get this all sorted yet staleb?

That's usually the start of electrical issues.

Sounds like you have a stock gauge cluster then? Did you happen to paint the housing as well as the dash?
Old IVR still handy by any chance? Just to swap things around to see what's going on.

Sounds good so far.

What does that mean exactly?

Good practice. Where exactly did you attach that to the dash panel?



Factory gauges still, but what about the sending units? Are they Explorer based, or original Bronco based?
You need both types if you're going to run the Explorer EFI and use older gauges that read from a different ohm range.
The fuel sender is finicky however, and 3/4 full seems to be the normal max.

Do you know how much fuel is in the tank exactly?
Have you verified accuracy with an external thermometer?
Can you get a mechanical gauge in the oil system at least temporarily so that you know what's going on?
Is this a newly rebuilt engine? Original Bronco? Original Explorer?

Well, I could say that it's "something with the gauges" but what it sounds like from here is "something with the grounding" instead.

Attach a jumper ground directly to the screw holding the IVR to the cluster. Attach a ground strap/wire to the dash, and to that bolt you have on the firewall. Or is that what you already have?
Forget the fuel at this point, because it might not be able to send an accurate signal at this point. Yet..
Is it a new sending unit?
Once you get the thing fully grounded and working with the other two gauges, then pull the fuel sender and tweak it until the gauge reads to your satisfaction.

Good luck. Can't help but think it's still a grounding issue at this point.

Paul

Thanks Paul and sorry for the delay. Went on vacation and just getting back to sorting through the issues.

Original gauges. Don’t have the old IVR. Not sure on if I have both sending units being used but assume so. Will look at that later tonight.

It’s an original explorer engine and not rebuilt. All sending units are old and not replaced. My grounds all look to be good and the gauges are grounded through a dedicated ground and aren’t being grounded through the bolts now. Oil and temp still read well below what they should. I have a feeling I might have killed the sending units. Believe there was a time I was pushing 12v constantly to them bc I hadn’t connected the IVR yet when I was finishing up the painless harness. I’ll focus on the oil and water first, but how do I check on functionality of the sending units?

 

[DirtDonk]

While I've never heard of a sender being damaged by 12v, that doesn't mean it can't happen.
But the main issue here, I think, is that your senders are completely incompatible with your gauges. Completely different OHM range between the '60's and '70's gauges, vs the later '80's and beyond.
So what you need are, Explorer sending units for the Explorer computer to reference, AND standard Early Bronco senders for the gauges.
Probably the only one you don't need is the fuel sender, which should be just for the gauge.

Not being a repeat-expert myself, I can't remember if the ECU needs oil pressure or not (probably does?) but it certainly needs water temp. So at the very least you're going to need two different water temp senders (one for gauge, one for ECU) and possibly two oil pressure senders.

Paul