I have a problem with my 73 F250 dash. When I bought it, no lights worked in the dash and no gauges worked. I replaced the I.C. voltage regulator and the lights started working as did the oil pressure gauge. Now the gas gauge,volt meter, and temp gauges are still out. I used a test light and I get a flashing light at all the gauge backs and ICVR. Also get flashing light at fuel sending unit at the tank.( I also cleaned all terminals and grounds already). Any suggestions as to what to try now and how to do it ? Thanks for any and all help offered.

Hello Ford Guy..Your issue could be several things and difficult to diagnose sitting in front of a computer.I to had many electrical issues with my 79 dash cluster and spent a lot of time only to yeild no results.some of the wiring was hacked up from previous owner along with intensive heat damage from the being a western Truck.what i did was located a decent doner vehicle (it wasnt easy and took a yr to find a good one here in Ohio) I removed & replaced the whole wiring harness in the cab and under the hood.I also replaced the dash cluster with the doner vehicle's since i new it worked correctly.I tied in my existing bed wiring and Bingo she was fixed.spent a good weekend doing the work & should have done it from the start.All In All it is not that bad of a job to do( It beats banging your head against the wall trying to trouble shoot it),Most of it is simple plug ins to existing components.a role of masking tape helps to mark where things go if your not sure.I am no electrician by any means.I took my time,had patience and it all worked out fine.with you being in a southern state,there may be some salvage vehicles available to you.I would start there.or look into the archives here for wiring diagrams to repair yours.you can also go to Autozones website sign up and find diagrams there.

Thanks BuzzGun79. I just bought the truck after it was sitting under a carport for 10 years. Could be a "field mouse" issue for sure, but most of the harness I can see looks good, so I'll try and run down the whole harness and connections. Most of the local salvage yards have scrapped all the stuff that old, compliments of the government clean up programs, plus the high cost of scrap metals make the worth more than the sum of their parts.
The main problem I don't understand is if all the gauges, ICVR, and the wires all the way to the fuel tank are getting "juice", but it is a flashing amount at all ends, it seems there should be something causing the flashing. I've bought 2 ICVR's and they both flash the test light, so I ruled that out, plus with all 3 gauges out, I'm guessing whatever has 1 out, has the other 2 out also. This brilliant deduction from an excellent "back yard stereo installer". lol
Thanks again.

Ford guy,you should get a pulse signal (flashing) for your fuel gauge,temp,oil pressure.check all grounds and dash grounds as well.It could also be a bad cluster circiut board as well.they are notorius for going out and have to be very clean in order to function properly.also check condition of the oil & temp sensors on the engine.The Volt meter feeds from the alternator/ignition switch lead at the cluster it is usually the black wire that has constant voltage with the key on.

I ran an ohm meter at the fuel and water temp sending units and got 0, so I'm thinking now it may be the sending units.The test light flashes strong at both connections on the harness, so I figured I'd buy the water temp one, being that it is cheap, and if that fixes it I might have it worked out.
Thanks for the suggestions BuzzGun.

You are SUPPOSED to have a 5 volts pulsing at those gauges and ICVR

That's how they work,





Is the cluster grounded at the dash support ?

I suggest you first remove the gauges and clean the contacts if they look white lie this?.

The cluster has no wires going directly to the support for a ground. The only wires connecting it is the loom plugged into the back of the cluster. Should there be a separate wire going to the support, and where should it connect to the circuit board?
All of the circuit board terminals are clean and tight, so I'll take it out again and re-check all the wires, which now is no big deal, 2 minutes tops.
Thanks Mil1ion.

There should be a black wire located in the connector that fastens to the dash brace

I can show you a pic ?

I took it apart again this morning and no wire from the main connection to the board is grounded to the dash brace that I can find. Please post a picture of how it should be. Thanks.

Hang on a bit I forgot that 73 is a bit different than 74/75

You must have the cluster with wiring for the dash illumination bulbs.correct ?

The bulbs do not have wires, the are set in the circuit board in black caps. I tried hooking up a ground wire to the screw that holds the ICVR, and that didn't help any, gauges still out.

Look at this diagram since it is from a 72 which should be closer to the 73 than a 75 would be

1974 was year when they had different cluster set up

removed for redundancy

Please note : UU51GA is the connection to ground I am talking about

after you spot UU51GA..follow the bottom of the two wires connecting to groud and you will see it goes into the wiring loom not the connector

The black wire (s) coming out of the connector all go into the loom then to the ground point

Found it. Now I will try to make sure the connection is good and goes all the way back to the connector. Thanks again Mil1ion