What's the best 12v switched power source.....

[OwdKasd]

.......for interior? I'm finally hooking up my Autometer Oil Pressure and Temperature gauges. Should I just come right off the Fuse Block? I could also use unswitched and install a mini toggle switch with an inline fuse.
Thanks,
Gerry

 

[67Dart273]

UN fused switched power comes from the key to the accessory buss in the fuse panel. So the fuse panel is "it."

If you want "run only" there is only ONE wire, so called IGN1 or "igntion run." It is also UNfused, goes to the cluster to supply the warning lights and gauge power, and branches off through the bulkhead to supply ignition, regulator, alternator field, etc

If you want to go to the trouble of splicing into the cluster power feed (hard to get to) and add an inline fuse of say, 5A or less, you could use that, which would then only power the gauges with key in "run"

Otherwise, any handy tab in the rear of the fuse box, on the switched buss, and put an inline fuse in that.

Lamp power is almost any orange wire from the dash lamp dimmer, IE radio connector

 

[OwdKasd]

UN fused switched power comes from the key to the accessory buss in the fuse panel. So the fuse panel is "it."

If you want "run only" there is only ONE wire, so called IGN1 or "igntion run." It is also UNfused, goes to the cluster to supply the warning lights and gauge power, and branches off through the bulkhead to supply ignition, regulator, alternator field, etc

If you want to go to the trouble of splicing into the cluster power feed (hard to get to) and add an inline fuse of say, 5A or less, you could use that, which would then only power the gauges with key in "run"

Otherwise, any handy tab in the rear of the fuse box, on the switched buss, and put an inline fuse in that.

Lamp power is almost any orange wire from the dash lamp dimmer, IE radio connector

Thanks so much. This is exactly what I needed.

 

[OwdKasd]

Found a few orange wires but none had pwr w/lites on. Dash lites inop also. It's real hard to trace the wiring so I'm thinking I'll just pull the cluster. Other than Speedo cable how much trouble is it?

 

[BillGrissom]

Either the fuse box or the ign switch, whichever is closer to your gages. At the fuse box, you can get taps that slip over the round fuse and let you attach a spade lug. At the ign switch, if you don't want to cut your factory wires, you can do like me and remove the "56 terminal" from the connector (use thin screwdriver) and insert a new wire that goes to a junction where you plug in your existing wire. I ran it to a 40 A relay coil (wired base) so the ign switch doesn't carry the ACC current (good idea, not essential).

 

[OwdKasd]

Either the fuse box or the ign switch, whichever is closer to your gages. At the fuse box, you can get taps that slip over the round fuse and let you attach a spade lug. At the ign switch, if you don't want to cut your factory wires, you can do like me and remove the "56 terminal" from the connector (use thin screwdriver) and insert a new wire that goes to a junction where you plug in your existing wire. I ran it to a 40 A relay coil (wired base) so the ign switch doesn't carry the ACC current (good idea, not essential).

Thanks, I see where there some tabs on the top of the Fuse block. I thought I could use a connector to push on one of those that had pwr w/key on. My problem now is no dash lites at all so I'm trying to fix them. Then I can tap into the orange wire for lites for the new gauges.

 

[67Dart273]

OK, dash lights are a bit of a trick. There is ONE small fuse which ONLY supplies instrument power but that fuse is AFTER the dash lamp dimmer control

The headlight switch receives TWO separate power circuits

The HEADLIGHTS get UN fused power from the "in harness splice," coming from the ammeter circuit. This wire suppplies ONLY the headlights and the switch has a breaker for this in/ on the switch

TAIL/ PARK get their power from a fuse in the panel, and this power ALSO FEEDS power to the dash dimmer control. AFTER power goes through the dimmier THEN this power goes to the small instrument fuse.

So......................

The very first thing to do is determine if you have power at the instrument fuse

Turn light switch to park/ tail, twist dimmer to left, and check power at both fuse clips



One thing you might try, is to vigorously twist the dimmer control back and forth several (8 or 10) times and see if you get any power at the fuse. While chekcing power at the fuse, slowly twist the dimmer, as they sometimes make contact in "one or two" spots.

IF you have no power there at the inst. fuse, and IF you DO have tail/ park lamps, it's time to pull out the headlight switch Very common for the dimmer control to get corroded/ rusty, the rubbing contact to break, etc.

Are you familiar with pulling the light switch? There's a release button up on the light switch frame. Unhook the battery, and pull the knob out to "lights", then wiggle the knob while pushing the release button. The entire knob and shaft will pull right out

 

[OwdKasd]

Thanks, This is precisely what I was just wondering because there's no power to the main Orange wire but all exterior lites work except for red marker lite in dr rear qtr panel.. I was thinking H/lamp switch. So I obviously have power to/through the H/lamp switch. This all tells me that I have BOTH power supplies to H/Lamp switch Right??

OK, dash lights are a bit of a trick. There is ONE small fuse which ONLY supplies instrument power but that fuse is AFTER the dash lamp dimmer control

The headlight switch receives TWO separate power circuits

The HEADLIGHTS get UN fused power from the "in harness splice," coming from the ammeter circuit. This wire suppplies ONLY the headlights and the switch has a breaker for this in/ on the switch

TAIL/ PARK get their power from a fuse in the panel, and this power ALSO FEEDS power to the dash dimmer control. AFTER power goes through the dimmier THEN this power goes to the small instrument fuse.

So......................

The very first thing to do is determine if you have power at the instrument fuse

Turn light switch to park/ tail, twist dimmer to left, and check power at both fuse clips



One thing you might try, is to vigorously twist the dimmer control back and forth several (8 or 10) times and see if you get any power at the fuse. While chekcing power at the fuse, slowly twist the dimmer, as they sometimes make contact in "one or two" spots.

IF you have no power there at the inst. fuse, and IF you DO have tail/ park lamps, it's time to pull out the headlight switch Very common for the dimmer control to get corroded/ rusty, the rubbing contact to break, etc.

Are you familiar with pulling the light switch? There's a release button up on the light switch frame. Unhook the battery, and pull the knob out to "lights", then wiggle the knob while pushing the release button. The entire knob and shaft will pull right out

 

[67Dart273]

Yep. If the tail light/ park/ markers work, then the dimmer control is getting power.

So check now at the instrument fuse, and if no power there, it's either a bad dimmer control at the headlight switch, or a connection in between. If you look at the rear of your fuse panel, the inst. fuse is "all by itself" with a tan coming IN from the switch, orange going OUT to all dimmer controlled lamps.

 

[Bulldozer]

wiggle the knob while pushing the release button. The entire knob and shaft will pull right out

well i'll be smacked with a 4-way . i learn something every time i log in here and today is no different. so THATS what the trick is. ive broken a few of them trying to get the knob off

thanks for that tidbit

 

[OwdKasd]

Yep. If the tail light/ park/ markers work, then the dimmer control is getting power.

So check now at the instrument fuse, and if no power there, it's either a bad dimmer control at the headlight switch, or a connection in between. If you look at the rear of your fuse panel, the inst. fuse is "all by itself" with a tan coming IN from the switch, orange going OUT to all dimmer controlled lamps.

Are you saying this instrument fuse is on the back side of the fuse panel? Or where is it? I did look at the schematics and just can't seem to spot it.

 

[67Dart273]

It's in the fuse panel. There are two groups of fuses, and then this one, which is connected electrically "special" On some years, at least, it's at the end of the panel. Should be the smalles (4.5a?) fuse in the panel

One group is the "hot buss" IE the ones which are hot always like the tail lights

The second group is the "switched acessory" group like the heater, radio, which must have the key on

Here's a shot of the panel, the inst. fuse is at far right

The top wire (tan) is the output of the dimmer control. Bottom wire going out is the orange going to all the dash lamps

The headlight switch is follows:

P is not used on later model cars, used to be for park lights. Now they are hooked to the R terminal..........

R is tail, park, marker lights

B1 is UNfused power coming TO the switch ONLY for headlights. This power comes from the splice in the ammeter circuit

B2 is tail power, comes from tail lamp fuse

H is headlight power feeding to the dimmer switch

D is the dome light switch, IE when you turn the knob all the way left, D gets grounded and activates the dome lights, just like your door switches. Most yellows are dome light switch wiring

INST is your interest. This is the output of the dash lamp dimmer, feeding down to the INST fuse in the panel.

 

[OwdKasd]

Okay, All fuses have power at both sides. Some need the ignition in run position. I just got done installing the gauges. Mounted, wired, sending units etc..

67DART273, If I'm understanding your post above...Power on both sides of the instrument fuse means that the dimmer portion of the switch is okay. Which would mean that somewhere between the wire coming from the fuse panel to the instrument panel I have a broken circuit. Correct?
Thanks again for the help,