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Need help with Guage Cluster.

OP
OP
C

Chadillac

New Member
Joined
Feb 20, 2017
Messages
19
My work schedule is crazy this week. I will have to tackle it this weekend. Thanks for the help! I will keep you updated.
 
OP
OP
C

Chadillac

New Member
Joined
Feb 20, 2017
Messages
19
Update

So I put the original IVR in and put a test light on the power out. The light just stayed on. Also the gas, oil and water temp pegged out.

Put the new IVR in and put the test light to it. The light was blinking. Put the test light on the temp and oil gauge power and the light was blinking.

I started it up with the new IVR and the oil went to 40 and slow fluctuates between 40 and 30. The water temp does not move. The gas gauge now does not move. The alternator is at zero. I turned it off and restarted it. All the gauges did the same but the water temp went right to 180 and then slowly dropped to zero and never moved after that.

So now where do I go from here?
 

Skiddy

Bronco Guru
Joined
Oct 8, 2003
Messages
11,557
looks like the new IVR is working. oil pressure sounds like its working. not sure on the other two. how new is your water sending unit? and is in one for it and not for a light? sorry if I missed it somewhere
 
OP
OP
C

Chadillac

New Member
Joined
Feb 20, 2017
Messages
19
As far as I know the water temp sensor in the top of the manifold is the original. Just a guess but everything on this Bronco has been original so far so I am assuming that would be. I picked up a new one on the way home. I will put that in tomorrow morning and see what happens.

As for the alternator....what would be a good number for it to show? Right now it is at zero or to be real precise it will move to about 5ish on the up side. Going towards the C.

Gas gauge??? The switch is brand new from Toms.

Thanks for all the help!
 

Brent13

Sr. Member
Joined
Aug 1, 2015
Messages
673
Loc.
Colorado Springs
Going towards C is good, meaning you are charging. Below zero, and you are at a deficit charge, as in going towards dead electrically. Sounds like your Alt meter is working. And also sounds like you have the Alt wire routed correctly. Route it the opposite way, and you will show a deficit, but you will still be charging, just will give you a false reading.

Aren't electrical issues just the best? I have been there, my wiring harness was a fire waiting to burn. I did a Painless harness, best move I ever made. Still hate electrical issues though, but now I have none, for now.
 

September 1972

Jr. Member
Joined
Apr 27, 2017
Messages
136
Grounding the cluster is required but clips may not be enough. Good 12 gauge wire with round terminals and nuts and bolts will ensure a good connection. The ammeter may be leaking voltage or there is a intermittent break in a wire behind the dash.

The cluster needs to be bench tested with extended wire run from the senders and power and ground. If it works on the bench but not in the dash then you start looking for a bad connection somewhere in the car. It might be one of the gauges is bad or intermittent so they should be dismantled and cleaned.

The good part is that when you become proficient at fixing the problem on the bronco you will be in a position to fix just about anything electrical! It's important to know what to look for and to qualify circuits in a logical order so that you progress toward the solution.

You are bouncing back and forth and may accidently get everything to work but without positively identifying the cause of the fault or faults it's likely to return to haunt you.

I found a wiring diagram and from the IVR there are three voltage drops in order, oil, temp, and fuel. The ground for the gauge circuit is the cluster case. The gauges are attached to the case by screws and since the voltage and current is very low
then if there's weak ground then the first drop which is the oil gauge could work and not the other two. In addition, how the gauge electrically works and where the ground point is located on the gauge case would be useful to know. In any event, 40 to 50 years old gauges need to be dismantled and cleaned at minimum to achieve any kind of reliability.
 
Last edited:
OP
OP
C

Chadillac

New Member
Joined
Feb 20, 2017
Messages
19
Grounding the cluster is required but clips may not be enough. Good 12 gauge wire with round terminals and nuts and bolts will ensure a good connection. The ammeter may be leaking voltage or there is a intermittent break in a wire behind the dash.

The cluster needs to be bench tested with extended wire run from the senders and power and ground. If it works on the bench but not in the dash then you start looking for a bad connection somewhere in the car. It might be one of the gauges is bad or intermittent so they should be dismantled and cleaned.

The good part is that when you become proficient at fixing the problem on the bronco you will be in a position to fix just about anything electrical! It's important to know what to look for and to qualify circuits in a logical order so that you progress toward the solution.

You are bouncing back and forth and may accidently get everything to work but without positively identifying the cause of the fault or faults it's likely to return to haunt you.

I found a wiring diagram and from the IVR there are three voltage drops in order, oil, temp, and fuel. The ground for the gauge circuit is the cluster case. The gauges are attached to the case by screws and since the voltage and current is very low
then if there's weak ground then the first drop which is the oil gauge could work and not the other two. In addition, how the gauge electrically works and where the ground point is located on the gauge case would be useful to know. In any event, 40 to 50 years old gauges need to be dismantled and cleaned at minimum to achieve any kind of reliability.

I will try one last attempt to ground the gauge cluster. If that does not work then I will pull it, bench test and clean the gauges. I was really hoping I would not have to pull the cluster. Ugh

Would you suggest running grounds from each screw that holds the gauge cluster to the dash? Or what would you say is the best way to ground?

Also I put in the new water temp sensor and it is doing the same thing. Not working when running. If I turn it off after it is warm and turn it back on it will rise to 160 or 180 and then drift back to zero.
 

September 1972

Jr. Member
Joined
Apr 27, 2017
Messages
136
Okay, can you make 4 gauge cables or do you buy them? I'll measure my 72 and provide instructions and pictures to bullet proof the grounding system which is where we start. Do you have a amp clip?
 
OP
OP
C

Chadillac

New Member
Joined
Feb 20, 2017
Messages
19
Okay, can you make 4 gauge cables or do you buy them? I'll measure my 72 and provide instructions and pictures to bullet proof the grounding system which is where we start. Do you have a amp clip?

Ah man that would be awesome! Thanks!

Amp clip?? I don't know much about electronics. Lol

I will look it up. Lol
 
OP
OP
C

Chadillac

New Member
Joined
Feb 20, 2017
Messages
19
Something new today. Now my right blinker dash light stays on. Not blinking but stays on constantly. Even when I use the left it stays on. When I use the right it will blink but then turn it off and it stays on. It does it when the headlights are on.
 
OP
OP
C

Chadillac

New Member
Joined
Feb 20, 2017
Messages
19
Easy fix. The bulb was not in all the way. Why can't the gauges be that easy? Lol
 
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