Hello again Ford fans,
So my 65 F100 with the sweep instrument panel has both an idiot light and a gauge for ALT and the oil pressure. Neither the ALT gauge or light do anything, the oil pressure light does nothing, the gauge pegs out on high when first started and slowly drops to zero within about 30 seconds.
If you guys have experience with these issues I would appreciate your input.
Thanks

 

Hi Jones1965. Tho I don't have that sweep panel, operation of gauges, idiot lights are usually fundamental. Couple questions.
1- Do you have 4 gauges, plus the 2 idiot lights (oil and amp/alt)?? Is it the stock Ford Custom cab panel or an aftermarket??
2- Engine OFF, ignition (ign) switch on, in the run position. Are the oil and amp lights on, illuminated?? They should be normally.
3- Oil Pressure Gauge. Ign switch OFF, the gauge should be at 0 or resting position. Watch the gauge as you turn the ignition switch on. Does it remain in the resting position ??
4- With ign switch on to run position, engine OFF, look CLOSELY at the oil, temp and fuel gauge's and see if they are truly steady or slightly bouncing/ pulsating??

With oil gauge and oil idiot light, thinking there would be 2 sending units. One for the gauge, the other for the light. They should be on the housing the oil filter attaches to. The one with the dome would be for the gauge, the other, much smaller is for the light. Look and make sure that how the wires attach to each, have different push on's. The dome for the gauge, would have a threaded stud and it's wire would just push on it. The one for idiot light may have a male spade on it and it's wire having a female spade to push on it.

On testing everything, answer my questions and we'll get into it, Cap

 

Yes 4 gauges and 2 lights amp, temp, oil pressure and fuel. It is the stock custom cab dash.
The oil pressure and amp lights never come on.
The oil pressure gauge with the key off is at zero, turn key to run and gauge pegs out on high.
The oil pressure gauge remains pegged all the way on high with the key to run but when the engine is started the gauge Immediately starts it's slow descent to zero.
Regarding your last question, with the key in the run position engine not running, amp gauge remains solid the fuel gauge shows how much fuel In tank and the gauge needle remains solid the temperature gauge stays at zero and remains solid, Oil pressure gauge peggs itself out and the needle stays solid, but when the key is turned on The light that illuminates the oil pressure gauge comes on and that light pulses engine running or not.

 

Hello iicap,
I tried to reply I did something wrong my answers are under your post.
Thanks for your help.

 

I FORGOT TO ASK, 240/300 six or 352 V-8?? Of course location of senders are in different places, I was assuming you have V-8.
Do look at the wires for the 2 oil senders and the temp sender for condition, bare spots that might be touching metal.
Do the wires look like they've been repaired??

OK lets start with the oil gauge. Find the domed sender for the gauge, take the wire off of it and let hang free. Now ign ON, engine OFF. Look at the oil gauge, it should stay at zero. IF it still climbs all the way up, look for the wire on the smaller sender and take it off the sender. Test the oil gauge again, key ON, engine OFF. Does the gauge stay down or continue to climb?? IF IT Stays Down, touch that wire from the small sender to metal and see if the gauge goes up. IF IT DOES, that wire should be attached to the domed sender.

Also look and see if the light IN the Oil Gauge that was pulsating is no longer lit with the 2 sender wire disconnected ?? Again why I asked if both senders had same terminals, as they could be hooked up backwards, you didn't answer that??

Let's jump to all the bulbs in the dash panel. Need to test them to see if the all the bulbs are good and work. Remember they all have a single wire, so the panel has to be grounded while it's laid out from the dash for access, for the bulbs to light up. Start with the dash lights, Engine OFF, Key OFF, parking or headlights ON. Looks like 4 bulbs, 2 in the center panel for the fuel, temp and speedo and one each in the oil and alt gauges. Turn the headlight switch knob left and right for brighter, dimmer. IT is common for rust to build up on the rheostat that adjust brightness and lose a good connection, Turning the switch left and right rapidly about 10 seconds, will sorta polish the coil and have the bright/dim function working again.

The 2 upper bubs are for high beam indicator and turn signal. ONLY a single turn indicator for both left and right turn.
As far as the idiot lights, lowest in panel go FOR NOW, just need to test the bulbs. Simplest way to test all bulbs one at a time if any won't illuminate correctly for you, is to take the bulb to the truck battery, place it upright on the Pos + post and with a jumper wire to the Neg- post touch the jumper wire to metal body of the bulb. If good it will light.

That's it for tonight. Don't mind my Capital Letters, I'm not hollering, just pointing out. Cap

 

Hi iicap,
I have not looked for 2 senders for each but I do have a couple loose wires. Also the engine is a 76 302 cid it also has a C6.

 

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So, a 302, not a stock engine for your truck, supposing you bought the truck this way??? Port for the oil sender appears to be behind the fuel pump ahead or the oil filter as this picture shows. There appears to be an adapter that has two senders on it. Someones way to get 2 senders in a tight location, one for gauge and one for idiot light. So look and see if there is a sender or 2 on your engine and if any wires hooked to it/them?? IF there is and a wire(s) are on it, do the test for the gauge and eliminating the flashing light in the oil gauge, I have already described.

Did you test the bulbs??

 

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Here's another pic, That happens to be a sender for an Idiot Light. It is on what is called an Oil Pressure Sender Extender. You would want one with two outlets for two senders.

 

That will be my plan. Right now I have the wire from my oil pressure gauge going to my oil pressure switch for the light. I have tested my bulbs, some work and some not so much. I am thinking about replacing all the dash lights with LEDs I just don't know if the LEDs are dimmable.
I made zero headway on the Alt gauge or light today.

 

OK, glad your gaining on it. I understand, wire for the oil gauge was/is hooked to the idiot light sender. Do you see a second oil sender/switch?? Maybe whoever did the engine swap just never bothered to hook all up correctly. The correct wire forthe light has to be there there also.

To understand the oil light operation. When the engine is off, the switch/sender is in ground mode, that is when you turn the ign on there is power thru the bulb to the switch/sender and the bulb will illuminate. When you start the engine and the oil pressure comes up and the switch/sender opens internally and the ground is lost, bulb goes out.

The light for the Alt is controlled by the Voltage Regulator. For now you need to verify that the bulb is good

I have no idea if the LED dash bulbs are dim-able.

 

iicap,
I have looked everywhere there is no oil pressure sending unit. I've no doubt lots of 76 302 vehicles only had oil lights. So I think I'm good there. As to the Alt gauge, it has the bulb and it's two wires plus 2 big wires like 10 ga on the back. One I'm sure goes right to the battery side of the starter solenoid the other I thing goes through either the ignition switch or light switch or maybe both. But then it also terminates at the battery side of the starter solenoid. I don't see how that can be right but don't know where it should connect. The truck has an alternator and there is no external voltage regulator. I've been looking for an applicable wiring diagram but no luck.

As for the LEDs that a no go, my dash lights are grounded through the center connection rather than the outside of the bulb housing. The LEDs have to be grounded through the outside.
I knew this truck was going to be a pain in the ass, for just these reasons. I appreciate your help.

 

Wow, I guess much to say. Because many mods to this truck of yours.

Just for reference, open this thread from FTE, with post #9 by BKW, Number Dummy, who I mentioned as our Parts Guru, explaining the variations of the Standard and Custom Cab instrument panels. I'll go back to your last post #11 later.

https://www.ford-trucks.com/forums/475749-dash-wiring-1965-f100.html

Cap

 

On Your last post. DO YOU want to get your 65 gauges AND lights working??? Whether the 76, 302 had an idiot light only, is not a factor. The only challenge I see is getting the Alt light working. It depends on whether the Alternator you has the capability of operating the Alt light.

One more question here. The wires ( you say 10 gauge ) on the Alt Gauge, do they come out of the harness right there, or are they running by themselves out thru the firewall, to the starter solenoid, battery cable side?? The second wire attaching to a wire right there, near the solenoid ??

An applicable schematic of your truck will not help because of the mods to your truck. Let's just say the Mod's to your truck were, never, completed.

 

iicap,
Yes I would like for the gauges and the idiot lights to work beings that I have them but obviously the gauges mean more to me than the lights. The large wires come straight off the back of the alt meter and straight to the starter solenoid. the side of the solenoid where the wire from the battery and the wire from the alternator both go. I have taken one of the wires from the amp gauge and connected it directly to the positive side of my battery and now my ALT gauge appears to be working when I start the truck it most assuredly shows a discharge on the gauge but then the gauge returns to zero and is not indicating a charging condition I know my charging system is working I've owned the truck for months and the battery is always plenty charged not sure what this tells me.

 

Hi J1965. So lets see if we can get your Alt meter working correctly. Don't forget you don't have all stock wiring now, some has been removed or just there doing nothing.

You MUST disconnect the battery when doing this, for saftey and we will test for all correct before you attach the battery ground up permanently. The two wires from the gauge MUST be routed and secured so no chaffing of the insulation can lead to a short, in the life of the truck.

Remove the two wires FROM the Alt gauge, AT THE SOLENOID, leave not touching anything at this time. As well the battery cable and alternator cable on the battery side of the solenoid, there should be another wire that feeds the whole truck, except the Horn. You need to find this wire and should be right there, it would have had a ring eye on it, to go on the stud with the Battery and Alternator cables. This wire that feeds the whole truck is the only wire that gets modified to install a Alt/Ammeter.

(IF you read the link I sent and the write up by, BKW, The Number Dummy, he said that Alt and Oil gauges did NOT come with ALL Custom Cab's, they were an option and the wires for the Alt gauge would be in the harness under the dash, at the gauge. SO, your gauges were added by a PO)

Back to hooking up the two wires from the gauge. Have you found the wire that feeds the truck. This feed wire, you remove it from the solenoid stud, if it's on there. Now the two wires from the Alt meter. One goes on the stud with the battery and alt wires and tighten all. The other is going to hook to the wire that feeds the whole truck. If all was stock you would cut the ring eye from the whole truck feed wire and using a correct ButtConnector, hook it to the remaining wire to the gauge. Hook the Pos battery cable to the battery, if it has been removed. The Neg is off and we will test now.

Everything in the truck MUST BE OFF, ign, lights, doors closed if you have interior light that goes on when opening the doors. Would hope you have a test light. Clip test light to the neg battery cable, touch the probe of test light to the neg battery post. The test light should be OFF, not lit. If lit, some thing in the truck is on / drawing current, recheck all is off. Next put the neg battery cable on, DON'T tighten yet. Put your head lights on and look at the Alt Meter, it should show - Discharge, IF it shows + Charge, you need to reverse the two wires at the gauge. Disconnect battery before correcting/reversing the wires.

A comment. I don't think all the charge going to the battery is going to show on the Alt gauge. That's OK, the battery will received all it's suppose to. You need tell me the Alternator you have, Make and 1,2 or 3 wire. Believe you said the is not visible Voltage Regulator ?