Dash gauges don't work

D

dutch1023

New member
Hey, just joined the forum. I have a 48 f1 that i converted to 12 volt with an alternator. Kept my old gauges but none of them work. Any ideas for what i can do to get them working?
 
You can check out your gauges by putting 6 volts to them, see if there is a polarity change.If they work on 6 volts they are ok, if not you will replace the gauge.
 
You may be lucky, many's the time guys have 12V jumped a 6V system unknowingly and the gauges still worked. Buy the Voltage lowering resisters and 12V bulbs for all lights and try again. You have better than a 50 50 chance the gauges will work. If not then replace the gauge or gauges that are fried. Try first though.
 
AnthonyG said:
You may be lucky, many's the time guys have 12V jumped a 6V system unknowingly and the gauges still worked. Buy the Voltage lowering resisters and 12V bulbs for all lights and try again. You have better than a 50 50 chance the gauges will work. If not then replace the gauge or gauges that are fried. Try first though.
Click to expand...

Hello Tony,where can I buy gauges for my 51 F1 ?,the oil pressure and temp guage don't work and I,v never seen repro,s for sale with the big boys ,cheers Jim.
 
37Coop- There are no repo gauges out there. You have to look for NOS gauges. Best place to look is Ebay. Is your truck 6v or 12v? Have you tested the gauges by removing the wire off each corresponding sender and touching that wire to a good ground with the key on? If it reacts and pegs the needle, then the sending unit is bad, not the gauge. If no movement, bad gauge. Same thing applies to 12v, but you need the voltage reducer on a 12V system. All USA Ford gauges were meant to operate on 6 volts up until 1986.
 
Hey Don-wi. I put a voltage reducer in the line for my gas gauge but not the others. I was told it was only needed for the gas gauge. Thanks.
 
dutch, Here's a wiring diagram for 48 Ford truck. It shows an ammeter instead of a volt meter. Is this what you have? If you currently have an ammeter consider replacing it with a volt meter as it is much safer. The key word here is "REPLACING" not "CONVERTING" the ammeter to a volt meter. I hope others with more electrical expertise on how to rewire your electrical system for this "replacing" will chime in as I am not an expert.
http://www.jalopyjournal.com/forum/...ical expertise, will chime in, I hope.730942/
http://www.auto-wiring-diagram.com/...4/wiring-diagram-of-1948-1949-ford-trucks.jpg
 
Last edited:
Here's the wiring diagram.

The reducer is needed for everything but the ammeter. Either individual Runtz-type reducers for each gauge or a single Instrument Voltage Regulator from a '57 - '86 Ford car or truck.
 

Attachments

  • Flathead_Electrical_wiring1948-49truck.jpg
    Flathead_Electrical_wiring1948-49truck.jpg
    95.3 KB · Views: 26
Ross, Would it be possible to install the Voltage regulator as you suggested and also install a Voltmeter WITHOUT making any changes to the ammeter wiring?
Or, does the ammeter have to disconnected and the wires feeding it soldered together?
 
The ammeter on these is an inductive type, with a loop that the battery feed wire passes thru. The only thing needed to do to "disconnect" it is to remove the end of the battery feed off the circuit breaker nearby, pull it back thru the loop, and reconnect it. There are people who have adapted an '80's Ford truck voltmeter to fit into the ammeter casing and into the dash, it's surprisingly easy if you get the right one.

Edit: '87-'89 Ford van and F-series voltmeters are an excellent fit.
 
ross f-1 said:
the ammeter on these is an inductive type, with a loop that the battery feed wire passes thru. The only thing needed to do to "disconnect" it is to remove the end of the battery feed off the circuit breaker nearby, pull it back thru the loop, and reconnect it. There are people who have adapted an '80's ford truck voltmeter to fit into the ammeter casing and into the dash, it's surprisingly easy if you get the right one.

Edit: '87-'89 ford van and f-series voltmeters are an excellent fit.
Click to expand...

Thank you.
 
I like the Runtz voltage regulators because they are small and bolt onto the back of the gauges. Just converted my 52 panel to 12v using flathead sending units on my 289 engine and the runtz regulators on the gauges. Works very well. I plan to add a diode off the starter solenoid to absorb the voltage spikes to protect the runtz.
 
No running an alternator. The collapsing magentic field of the coil in the starter solenoid induces a large spike on the power line that can kill electronics. If running the pertronics ignition or have other electronics you need a diode to suppress the spikes. If you look on newer ford solenoids they are stamped diode suppressed indicating a diode inside. Need one on all devices with a coil of wire like heater, wipers, horn, relays. Use a simple 1n4005 diode from radio shack. In theory should only need one on the main power line but they are cheap and the starter solenoid is the worst culprit so start there.
 
I don't know why they call it a 5v regulator; they sell the same one as a 6v and various other voltages for specific makes. Its output is adjustable (brass screw visible in one pic) and I run mine at 7.2v. The gauges don't really seem to be that particular about voltage anyway.
 
Barry-ct said:
37Coop- There are no repo gauges out there. You have to look for NOS gauges. Best place to look is Ebay. Is your truck 6v or 12v? Have you tested the gauges by removing the wire off each corresponding sender and touching that wire to a good ground with the key on? If it reacts and pegs the needle, then the sending unit is bad, not the gauge. If no movement, bad gauge. Same thing applies to 12v, but you need the voltage reducer on a 12V system. All USA Ford gauges were meant to operate on 6 volts up until 1986.
Click to expand...

Thanks Barry, its a recent import changed to 12v before I bought it .it didn't have any reducers on it ,the gas and battery dials work o.k ,the oil pressure gauge did work ,I then had the engine rebuilt and I rewired it wire by wire and when it was put together the oil gauge registered nil when running ,I changed the sender for a new repro and when the ignition is turned on the needle goes to maximum without the engine running ,the temp gauge has never moved since I,v had it , as you can guess electrics are a mystery to me .I will play with them tomorrow with your instructions in mind , many thanks Jim.
 
You must log in or register to reply here.
Back
Top