Wiring Gauges

Furyus67

Active Member
Joined
Aug 12, 2013
Messages
269
Reaction score
148
Location
Baltimore, MD
I am attempting to wire 3 Autometer gauges. I have been told the following:

To power the gauges, you want to find the Ignition (RUN) circuit. Which means that circuit always has +12V on it when the engine is running. You don't want to use the Ignition (RUN/ACC'Y) circuit because the gauges will be on (draining your battery) if you put the key in the accessory position counter-clockwise position (like when you're listening to the radio). Also, you don't want to use the Ignition (START/CRANK) as this circuit only has +12V when your starting/cranking the engine, but then goes away when the key goes back to the RUN position. As far as the backlighting, you can find any DIMMER circuit (also available on the instrument cluster)

With that being said, below is a picture of the wiring from my FSM. Is IGNITION the RUN circuit and IGNITION-2 the START/CRANK circuit?
IGN-1.jpg


Would I want to splice into the IGINITON wire or would I want to splice into something like the OIL or BRAKE lamp wire on the instrument cluster?
 

Big_John

Illegitimi non carborundum
FCBO Gold Member
Joined
May 21, 2013
Messages
16,679
Reaction score
22,877
Location
Marcellus, NY
Look on the back of your fuse block. There's two sides, basically one side is on with the ignition (radio etc.) Find a nice open connection. There sould be at least one and put a spade terminal on it. That's it... no splicing and dicing.

If you don't see an open one, head down to your local parts store and pick up a couple of these. Probably 3 or 4 in a package. They will let you stack an extra wire onto the existing group.

100pcs-10-22AWG-Insulated-Piggyback-Crimping-Terminals-Red-Blue-Yellow-Spade-Crimp-Connectors-Assorted-Kit-Mayitr.jpg
 

Mike66Chryslers

Senior Member
Joined
Apr 28, 2012
Messages
1,291
Reaction score
1,720
Location
Ontario, Canada
Unless this changed for '67 (which I highly doubt) the RUN circuit to power the ignition system is not fused through the fuse panel. You could remove every fuse from the fuse panel and still start the car. I know because I did that with my '66 Windsor when I was restoring it. The interior wiring harness was all over the place and I didn't want to risk shorting-out anything but still be able to move the car.

I just tapped into the ACCY/RUN circuit in the panel, using the method recommended by @Big_John . I figured the gauges are solid-state electronics and not going to draw that much current. I did look up the specs for the gauges and the current draw was very low, but I don't remember what it was offhand.
EDIT: I used two Speedhut gauges and they only draw 200mA each.

I had my Windsor at a drive-in last summer, listening to the movie sound through my car stereo, so it was in ACCY position for hours. No problem.
 
Last edited:

MrMoparCHP

Old Man with a Hat
Joined
Aug 9, 2013
Messages
5,331
Reaction score
4,974
Location
Lompoc, CA
There are two circuits on the fuse panel, Accessory and Battery.
Battery: Hot all the time, key on or off
Accessory: Hot only when the key is in the Run or Accessory position.

With the key off test the voltage on the fuse panel to determine which is which.


Alan
 

Furyus67

Active Member
Joined
Aug 12, 2013
Messages
269
Reaction score
148
Location
Baltimore, MD
Unless this changed for '67 (which I highly doubt) the RUN circuit to power the ignition system is not fused through the fuse panel. You could remove every fuse from the fuse panel and still start the car. I know because I did that with my '66 Windsor when I was restoring it. The interior wiring harness was all over the place and I didn't want to risk shorting-out anything but still be able to move the car.

I just tapped into the ACCY/RUN circuit in the panel, using the method recommended by @Big_John . I figured the gauges are solid-state electronics and not going to draw that much current. I did look up the specs for the gauges and the current draw was very low, but I don't remember what it was offhand.
EDIT: I used two Speedhut gauges and they only draw 200mA each.

I had my Windsor at a drive-in last summer, listening to the movie sound through my car stereo, so it was in ACCY position for hours. No problem.
Good to know. Thank you for the info!

I'm guessing that you're working on a 67 Fury. On my 68 NYer the was open slots just like the back of the fuse box Big_John showed above.
Sorry I always forget to say what I'm workin on. 1967 Plymouth Fury III, small block, non-AC car.

Here is my current fuse panel. I'll take it off tomorrow to see what the back is looking like.

IMG_0569.jpg
 

Polara_500

Member at Peace
Legendary Member
Joined
Apr 17, 2011
Messages
3,193
Reaction score
3,137
Location
MinnieSnowta
Good to know. Thank you for the info!


Sorry I always forget to say what I'm workin on. 1967 Plymouth Fury III, small block, non-AC car.

Here is my current fuse panel. I'll take it off tomorrow to see what the back is looking like.

View attachment 432796
Or you could just find a fuse clip to put in the blank ACC spot and feed off that...............
 

Furyus67

Active Member
Joined
Aug 12, 2013
Messages
269
Reaction score
148
Location
Baltimore, MD
While it's off, clean up some of those corroded terminals for the fuses, even the fuses themselves look like they could use a shot of steel wool too. Good electrical contact is important. Good Luck
Will do sir! All of this is on tomorrows agenda!
 

Furyus67

Active Member
Joined
Aug 12, 2013
Messages
269
Reaction score
148
Location
Baltimore, MD
For the oil pressure gauge if I’m using the Autometer gauge and sending unit, then I won’t be using the oil pressure dummy light. Which means I won’t have the factory wire for the dummy light hooked up on the new sending unit. Will that mean the dummy light will stay on all the time since the factory wire is not hooked up. Or does disconnecting the wire make the light not work at all.
 

Big_John

Illegitimi non carborundum
FCBO Gold Member
Joined
May 21, 2013
Messages
16,679
Reaction score
22,877
Location
Marcellus, NY
For the oil pressure gauge if I’m using the Autometer gauge and sending unit, then I won’t be using the oil pressure dummy light. Which means I won’t have the factory wire for the dummy light hooked up on the new sending unit. Will that mean the dummy light will stay on all the time since the factory wire is not hooked up. Or does disconnecting the wire make the light not work at all.
Disconnected, it won't work.

But! You can easily add a tee and keep the warning light too, or if you have a big block, look at the pressure sender and in the same spot on the opposite side of the engine, is another spot where you can just pull the plug and tap into the oil pressure there.

You can buy this cheaper local, but a brass street tee, 1/8 NPT, like this, will do the job nicely if you use a tee.

https://smile.amazon.com/gp/product/B006PKKXM4/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

81-vpIA5ffL._SL1500_.jpg
 

Furyus67

Active Member
Joined
Aug 12, 2013
Messages
269
Reaction score
148
Location
Baltimore, MD
Disconnected, it won't work.

But! You can easily add a tee and keep the warning light too, or if you have a big block, look at the pressure sender and in the same spot on the opposite side of the engine, is another spot where you can just pull the plug and tap into the oil pressure there.

You can buy this cheaper local, but a brass street tee, 1/8 NPT, like this, will do the job nicely if you use a tee.

https://smile.amazon.com/gp/product/B006PKKXM4/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

View attachment 433000
Thank you. I’ve got some brass tubing on order. I’m going to try to T it back there.
 

saylor

Senior Member
Joined
Mar 31, 2013
Messages
2,886
Reaction score
1,735
Location
GARLAND TEXAS BABY !!!
bro go to lowesdepot and get a brass tee and a 4" or 6" threaded brass pipe if you need to come up off the tee higher - you will be back in 30 minutes this is all plumbing aisle stuff.

try not to die -

- saylor
 

Furyus67

Active Member
Joined
Aug 12, 2013
Messages
269
Reaction score
148
Location
Baltimore, MD
bro go to lowesdepot and get a brass tee and a 4" or 6" threaded brass pipe if you need to come up off the tee higher - you will be back in 30 minutes this is all plumbing aisle stuff.

try not to die -

- saylor
I got the 4 and 6 inch. Not enough room. I’m workin on it. I’m not giving up on your advice yet. Haha
 

saylor

Senior Member
Joined
Mar 31, 2013
Messages
2,886
Reaction score
1,735
Location
GARLAND TEXAS BABY !!!
Good to know. Thank you for the info!


Sorry I always forget to say what I'm workin on. 1967 Plymouth Fury III, small block, non-AC car.

Here is my current fuse panel. I'll take it off tomorrow to see what the back is looking like.

View attachment 432796

20210124_142604.jpg
get a load of this...fusebox on this 2020 ram. i cant even see em i had to take a picture
 
Top