Connecting Aftermarket Gauges

BiggDogg · Post by **BiggDogg** » Tue Apr 01, 2008 2:33 pm

I fear this may be a dumb question, with an obvious answer, but I guess its better than not asking at all. We're installing the new aftermarket (round style) gauges this week with some luck. Anyhow, while comparing new gauges with the old, I'm not too sure about how to connect the new ones.

Original Setup:
-appears to be only two connection points, I'm assuming ground and sender right?

New Gauges:
-3 connection points: power, ground, sender
-I believe the gauges are electric, except the speedometer is mechanical

So my question: Am I missing something on the original setup, or is the power connection on the new gauges because the gauges are electric? Or something else that I'm totally not realizing? What do you guys think? Thanks!

Thunderfoot · Post by **Thunderfoot** » Wed Apr 02, 2008 2:31 pm

The way the gauges work is power goes to them ( key on ) then to the sending unit. The sending unit is the ground connection, it is a variable resistor that changes depending on what type of sending unit it is... The gauge reads this change and make the needle move accordingly... If you take the wire that goes to the sending units and ground them it will move the gauge to full limit...

On the new gauges you have, the ground could be for the instrument light, or the connection for the instrument light...

Do you have the instructions that came with the new gauges? is this how they are labeled? "power, ground, sender "

BiggDogg · Post by **BiggDogg** » Wed Apr 02, 2008 3:20 pm

Thunderfoot wrote:The way the gauges work is power goes to them ( key on ) then to the sending unit. The sending unit is the ground connection, it is a variable resistor that changes depending on what type of sending unit it is... The gauge reads this change and make the needle move accordingly... If you take the wire that goes to the sending units and ground them it will move the gauge to full limit...

On the new gauges you have, the ground could be for the instrument light, or the connection for the instrument light...

Do you have the instructions that came with the new gauges? is this how they are labeled? "power, ground, sender "

Thanks Thunderfoot. Yes, in the directions, they are labeled as "power, ground, sender "

Thunderfoot · Post by **Thunderfoot** » Fri Apr 04, 2008 12:09 pm

Sounds right then... the ground is probably used for the light in the gauge... With the plastic new car dashes you have to run a ground wire so the light will work, where as the old steal dashes would ground just fine from it mounted in there... So all newer gauges will have this ground wire.

FormerMarine1981 · Post by **FormerMarine1981** » Fri Apr 04, 2008 12:24 pm

So from what your saying the original gages just have a power and sender wire?? The ground is the only thing to add for newer gages?

rjewkes · Post by **rjewkes** » Fri Apr 04, 2008 3:10 pm

yup the ground was common for most of the dash..

BiggDogg · Post by **BiggDogg** » Sat Apr 05, 2008 12:31 am

Great thanks guys! Hopefully they'll be in and functioning soon. I'll post an update when we're finished!

SteveC · Post by **SteveC** » Sat Apr 05, 2008 12:39 am

yea a lot of our old tractor gauges and the gauges out of the international scout were only two wire...jsut like the ones in the 67-69 truck are two wire type

BiggDogg · Post by **BiggDogg** » Mon Apr 21, 2008 12:32 pm

Ok, new round style aftermarket gauges in, a few good, a few need some help. All the sending units were replaced with the new gauges, and a new float for the fuel tank:

The Good:
-turn signals work
-lights work
-temp gauge works
-volt gauge works

Needing help:
-oil pressure gauge is maxed out, but we tried to use the old sending unit, so I think we'll put the new one in first and see if that works before trying anything else.
-fuel gauge reads 1/4 tank with 3/4 tank worth of gas, I'm thinking we just need to fill the tank then adjust it accordingly.
-speedometer-no movement at all

Any ideas? Thanks!

Thunderfoot · Post by **Thunderfoot** » Mon Apr 21, 2008 3:46 pm

oil pressure gauge is maxed out, but we tried to use the old sending unit, so I think we'll put the new one in first and see if that works before trying anything else.

Yep, you will need to use the sending unit that is for that gauge, the old stock one wont work...

fuel gauge reads 1/4 tank with 3/4 tank worth of gas, I'm thinking we just need to fill the tank then adjust it accordingly.
-speedometer-no movement at all

That would be my guess if you put in a new sending unit that came with the gauge... There might be some procedure with the gauge that tells what to do to adjust it.

speedometer-no movement at all

Need more details on the gauge you used, Brand/type and how it is hooked up... Some of those need a special sending/decoding unit that mounts on the trans for the electronic ones...

BiggDogg · Post by **BiggDogg** » Mon Apr 21, 2008 5:17 pm

Thanks for the help Thunderfoot.

Thunderfoot wrote: That would be my guess if you put in a new sending unit that came with the gauge... There might be some procedure with the gauge that tells what to do to adjust it.

Yes we actually adjusted it once, but the tank wasn't full

so that was our goof ball mistake. I'll fill the tank then adjust it ans see if that works.

Thunderfoot wrote: Speedometer-Need more details on the gauge you used, Brand/type and how it is hooked up... Some of those need a special sending/decoding unit that mounts on the trans for the electronic ones...

Dolphin gauges. Looks like I need to buy a pulse generator to get it going.

Thunderfoot · Post by **Thunderfoot** » Mon Apr 21, 2008 5:46 pm

I couldn't think of the name earlier, but Pulse Generator is it

You'll have to post some pictures of the gauges all installed!!!

BiggDogg · Post by **BiggDogg** » Mon Apr 21, 2008 6:46 pm

Thunderfoot wrote: I couldn't think of the name earlier, but Pulse Generator is it

You'll have to post some pictures of the gauges all installed!!!

Yes definately thanks for all your help!

BiggDogg · Post by **BiggDogg** » Mon Apr 28, 2008 1:17 am

Alright, gauges in problems diagnosed, sorry no pics yet (I took one, but the truck was so dirty in the pic that I decided not to post it

.

-Installed the new sending unit for the oil pressure gauge, it works now.

-haven't had a chance to fill the tank yet...

-Speedometer: When checking the cable where it enters the transmission, I discovered that it was just dangling in the air catching a nice breeze, shredded, so I need to get a new speedo cable.

Also had a chance to install a new switch on the floor for the high beams so now I have high beams and low beams!

Also got the dome light working again.

I wasn't sure how the gauges would look at night... I'll have to get a picture on here of a night shot... I really like the way they look lit up!

BiggDogg · Post by **BiggDogg** » Mon May 19, 2008 3:26 pm

Post updated in my 'project update' thread here: http://www.fordification.com/forum/view ... 598#304598

The FORDification.com Forums

Connecting Aftermarket Gauges

Connecting Aftermarket Gauges

re: Connecting Aftermarket Gauges

Re: re: Connecting Aftermarket Gauges

re: Connecting Aftermarket Gauges

re: Connecting Aftermarket Gauges

re: Connecting Aftermarket Gauges

re: Connecting Aftermarket Gauges (update 4-20-08)

re: Connecting Aftermarket Gauges (update 4-20-08)

Re: re: Connecting Aftermarket Gauges (update 4-20-08)

re: Connecting Aftermarket Gauges (update 4-20-08)

re: Connecting Aftermarket Gauges (update 4-28-08)

re: Connecting Aftermarket Gauges (update 4-28-08)