gauges not working properly

[Beach Bronco]

Hi, I'm new to this site but I frequent another bronco site often. I'd like to be part of both communities /emoticons/[email protected] 2x" width="20" height="20" />

I'm having an issue with my dash gauges. the voltage gauge is not working/doesn't move at all. The oil press gauge reads low =below the normal range but I know I have good pressure. The gas gauge does not work but is believed to be the sender in the tank. The water temp is working fine.

Does anyone know how to test the individual gauges? The back of the cluster is that printed electronic circuit paper.

My truck is a 89 FSB 300 I6, 5 speed.

Thanks in advance!

 

[BroncoJoe19]

Steve,

Given this information, ...

Oil, temp, & gas gauges work the same using a power, a ground, & a signal circuit that goes to ground thru the sender; the volt gauge has no sender - just power & ground.

How would one test the guage?

 

[Beach Bronco]

Steve,Given this information, ...

Oil, temp, & gas gauges work the same using a power, a ground, & a signal circuit that goes to ground thru the sender; the volt gauge has no sender - just power & ground.

How would one test the guage?

^ Exactly what I was going to ask!

 

[Seabronc]

Hi, I'm new to this site but I frequent another bronco site often. I'd like to be part of both communities /emoticons/[email protected] 2x" width="20" height="20" />
I'm having an issue with my dash gauges. the voltage gauge is not working/doesn't move at all. The oil press gauge reads low =below the normal range but I know I have good pressure. The gas gauge does not work but is believed to be the sender in the tank. The water temp is working fine.

Does anyone know how to test the individual gauges? The back of the cluster is that printed electronic circuit paper.

My truck is a 89 FSB 300 I6, 5 speed.

Thanks in advance!

How do you know the oil pressure is good, are you using a wet gauge to measure it?

I don't recall off hand if an 89 has a voltage gauge or charge gauge. If it is in fact a voltage gauge, check with a meter at the back pins on the gauge and see if you get 12+ volts probably around 13.5 with the engine running. Yes, it has a printed Mylar flexible plastic circuit board.

Good luck,

>-

 

[Krafty]

you'll have to check the wiring harness diagrams to see which wires go where because I know that the 89's only have 2 plug ins at the back, one on each side. other that that all the circuitry is internally routed. I haven't found a way to pull it any further apart. But I could be wrong.

I would go after the sensors first. replace the sending unit in the tank, check the connections to the alternator for the wire going to the (STOCK) amp meter ( found in every 87 to 91 Bronco and F150 dash I have ever seen) , find and replace the oil pressure sensor, then if that doesn't work then follow the wires and check them for damage and connectivity to the harness, if that is fine then it looks like you might have to either tear apart your instrument cluster or replace it all together.

 

[Beach Bronco]

I pulled out the cluster to clean up the printed circuit board with an eraser and now my oil pres. gauge is working correctly but the amp meter still does not move and the fuel gauge still is pegged all the way full. I had a tough time trying to get the volt meter terminals behind the cluster so I'm going to test the wires in the harness and trace from there.

Where does the amp meter pickup the amperage signal from? It's on the alternator? Do you know what wires?

Since the fuel gauge moves when I start the truck (just goes to pegged full) one would think that it is getting a signal correct? Prob just the sending unit sending the wrong signal...

Thanks for the help.

 

[Krafty]

yeah the sending unit would be the one giving you the trouble for the fuel gauge, the fords are notorious for that, I had to swap out my sending unit when I put my truck on the road last month.

as far as the amp meter wires, it looks like the possible candidates coming off the alternator are the yellow, and green wires.

I only have the 1980 to 90 hynes book from when I had my 81 so they don't seem to go into detail on the 87 to 90 systems that much.

 

[Beach Bronco]

Thanks a lot. I'll check it out and post back. Appreciate the help.

 

[Krafty]

its a stock amp meter,

and its already been made clear that the sending unit is bad.

 

[Beach Bronco]

I think the connection is bad because when I was inspecting the printed circuit board I niticed that it had a small tear and was Scotch taped. What can I do about this?

 

[Krafty]

we were talking about the FUEL TANK sending unit. and I am aware that the Voltage meter only gets its feed from the alternator.

 

[Beach Bronco]

"Carefully solder a jumper wire from a good part of the trace, across the break, to any other part of the trace."

Steve 83, can you please advise what exactly the trace is? Do you mean the copper colored printed wire on the paper panel? That won't melt? Thanks in advance.