Rewiring OEM Instrument Cluster 75 FJ40 (1 Viewer)

[BDSeff1fitty]

Have installed the 20 circuit Painless harness. Just finished up today. I saw where someone was looking for instructions on wiring the OEM instrument cluster. I'll describe what I did, and hopefully it will be enough to be helpful even if you didn't do exactly as I did.

1. I took the instrument cluster out, and removed the 12 pin circular connector, and the two wires to the ammeter.

2. I took each of the lamps out of the instrument cluster and used very fine emery paper to clean the copper pads as mine had corroded up pretty well. Likewise I removed the nouts on the instruments (fuel guage, temp guage and oil guage. I cleaned the copper pads on these as well. Finally, I cleaned each of the 12 pins with emery paper wher ethe circular connector goes.

3. I cut the wires off the old harness where the round connector was, leaving about 4 inches of wire. (I had put all new vintage connectors everywhere else on the vehicle, but couldn't find this round connector so had to spilce the old connector wires onto the new wires.

4. I in-line twisted each wire to the new one, soldered, and slid weatherproof heatshrink over each solder joint to insulate them.

5. The Painless harness does not explicitely provide a switched power wire to the instrument cluster, nor does it provide a ground. You'll need both.

6. Here'e the wiring:

Pin -- Old color -- New Color -- Function

1 -- White/Black -- Black -- Ground

2 -- Yellow/Black -- Lt Blue/Black #722 -- Oil Sender

3 -- not used

4 -- Blue/Red -- Red/Blk -- Battery + (switched)

5 -- Yellow/Red -- Pink #739 -- Fuel Sender

6 -- Yellow/Green -- Lt Green #721 -- Temp Sender

7 -- Red/Yellow -- Green #736 -- Hi Beam Indicator

8 -- Blue/White -- (I didn't used) -- Veh Speed sensor to emission box

9 -- Green/Yellow -- Dk blue #738 -- Right turn indicator

10 -- not used

11 -- Green/Black -- Lt Blu #737 -- Left turn indicator

12 -- Red/Black -- Brown #730 -- Instr Panel Light

All seems to work fine.

 

[jp_waltz]

Dont suppose you took a picture of the back of the cluster after it got wired? So did you use the round connector? I dont have one on mine so im looking for alternatives.
Thanks
Paul

 

[hacdlux]

first post on the board been lurking a while

im in the process of doing my 75 with an ez wiring harness

i did the same reusing the round conector but my harness did have the instrument power, i did have to add a ground ootherwise it will ground through the turn signals

and i do have the comment of the ez/painless harnesses are anything but

side note:
i went to the junkyard and got a gm steering column conector
and light switch connector
and bought the gm light switch from pepboys $10.95

 

[BDSeff1fitty]

There's another post on here recently that had some pics. For many of the points, the terminal screw also exists in addition to the connection on the round connector, so you could wire directly there (all the instrument gauges). You can also use single barrel connectors that will fit over the individual pins. Frys Electronics sells some Molex connectors that have the female barrels included that would probably work.

If we end up pulling the panel back out over the next few days, I'll take a few pics.

 

[jdhouston]

Painless wiring Hazard Switch

i have some pain in my Painless regarding the Hazard Warning Switch, any advice would be great

 

[Hamachi]

Have installed the 20 circuit Painless harness. Just finished up today. I saw where someone was looking for instructions on wiring the OEM instrument cluster. I'll describe what I did, and hopefully it will be enough to be helpful even if you didn't do exactly as I did.

1. I took the instrument cluster out, and removed the 12 pin circular connector, and the two wires to the ammeter.

2. I took each of the lamps out of the instrument cluster and used very fine emery paper to clean the copper pads as mine had corroded up pretty well. Likewise I removed the nouts on the instruments (fuel guage, temp guage and oil guage. I cleaned the copper pads on these as well. Finally, I cleaned each of the 12 pins with emery paper wher ethe circular connector goes.

3. I cut the wires off the old harness where the round connector was, leaving about 4 inches of wire. (I had put all new vintage connectors everywhere else on the vehicle, but couldn't find this round connector so had to spilce the old connector wires onto the new wires.

4. I in-line twisted each wire to the new one, soldered, and slid weatherproof heatshrink over each solder joint to insulate them.

5. The Painless harness does not explicitely provide a switched power wire to the instrument cluster, nor does it provide a ground. You'll need both.

6. Here'e the wiring:

Pin -- Old color -- New Color -- Function

1 -- White/Black -- Black -- Ground

2 -- Yellow/Black -- Lt Blue/Black #722 -- Oil Sender

3 -- not used

4 -- Blue/Red -- Red/Blk -- Battery + (switched)

5 -- Yellow/Red -- Pink #739 -- Fuel Sender

6 -- Yellow/Green -- Lt Green #721 -- Temp Sender

7 -- Red/Yellow -- Green #736 -- Hi Beam Indicator

8 -- Blue/White -- (I didn't used) -- Veh Speed sensor to emission box

9 -- Green/Yellow -- Dk blue #738 -- Right turn indicator

10 -- not used

11 -- Green/Black -- Lt Blu #737 -- Left turn indicator

12 -- Red/Black -- Brown #730 -- Instr Panel Light

All seems to work fine.

hello,
I know this is an old thread, but how Did you reconnect the ammeter?
did you ever post pics?
thank you

 

[Hamachi]

hello,
I know this is an old thread, but how Did you reconnect the ammeter?
did you ever post pics?
thank you

I just saw your post.

search for coolerman here. He has posted the wiring diagram for this. I forgot how I did it...

 

[ToyotaMatt]

Have installed the 20 circuit Painless harness. Just finished up today. I saw where someone was looking for instructions on wiring the OEM instrument cluster. I'll describe what I did, and hopefully it will be enough to be helpful even if you didn't do exactly as I did.

1. I took the instrument cluster out, and removed the 12 pin circular connector, and the two wires to the ammeter.

2. I took each of the lamps out of the instrument cluster and used very fine emery paper to clean the copper pads as mine had corroded up pretty well. Likewise I removed the nouts on the instruments (fuel guage, temp guage and oil guage. I cleaned the copper pads on these as well. Finally, I cleaned each of the 12 pins with emery paper wher ethe circular connector goes.

3. I cut the wires off the old harness where the round connector was, leaving about 4 inches of wire. (I had put all new vintage connectors everywhere else on the vehicle, but couldn't find this round connector so had to spilce the old connector wires onto the new wires.

4. I in-line twisted each wire to the new one, soldered, and slid weatherproof heatshrink over each solder joint to insulate them.

5. The Painless harness does not explicitely provide a switched power wire to the instrument cluster, nor does it provide a ground. You'll need both.

6. Here'e the wiring:

Pin -- Old color -- New Color -- Function

1 -- White/Black -- Black -- Ground

2 -- Yellow/Black -- Lt Blue/Black #722 -- Oil Sender

3 -- not used

4 -- Blue/Red -- Red/Blk -- Battery + (switched)

5 -- Yellow/Red -- Pink #739 -- Fuel Sender

6 -- Yellow/Green -- Lt Green #721 -- Temp Sender

7 -- Red/Yellow -- Green #736 -- Hi Beam Indicator

8 -- Blue/White -- (I didn't used) -- Veh Speed sensor to emission box

9 -- Green/Yellow -- Dk blue #738 -- Right turn indicator

10 -- not used

11 -- Green/Black -- Lt Blu #737 -- Left turn indicator

12 -- Red/Black -- Brown #730 -- Instr Panel Light

All seems to work fine.

perhaps you take a close look at this and approach it from a factory oem correct way , ZERO guess work plug and pay with your painless ........

done

VintageTEqParts.com

vintageteqparts.com

 

[knuckle47]

Old post I know but: what does the 3 wire plug on the left do. It has white wires with a blue tracer and brown tracer and a black wire?

 

[bj40man]

I would also like to know what does these 3 wire plug do, as well...

 

[knuckle47]

As I have learned…it feeds the 50A ammeter with the correct power

 

[bj40man]

As I have learned…it feeds the 50A ammeter with the correct power

Thank you for the explanation.

 

[knuckle47]

Flip the cluster over and you will see the circuit board tracing to each binding post and the third goes off to the right

 

[bj40man]

Flip the cluster over and you will see the circuit board tracing to each binding post and the third goes off to the right

So, from your explanation without having looked at any, if I do not connect that socket, I can run the newer dash with an older vehicle, say what they call the third generation type 74-78 truck? Because these years have a different ammeter, right?

 

[knuckle47]

So, from your explanation without having looked at any, if I do not connect that socket, I can run the newer dash with an older vehicle, say what they call the third generation type 74-78 truck? Because these years have a different ammeter, right?

So..here’s what happened to me. My FJ45 had the old dash cluster, a 1979 non-US model. The fuel gauge needle pointer was broken off so they replaced the dash cluster with that new one you see all over the place. Since my original had a 30A ammeter, it was connected to each post on the back of the gauge,,,,the 10Gauge wires coming from the engine bay were simply tied together and heavily taped up to maintain a continuous circuit with the new dash. This is because the gauges use power in different ways. If you connect the heavy leads directly to the gauge you will burn it up. The new 50A is not really measuring amperage but almost like voltage. ALMOST…

My friend John , a big 1950’ s car guy and a hot rod builder told me a few days ago that this was done more as a safety feature as the electrical current in cars with ammeters had caused some fire issues. Well, that sounded good and logical so I’m happy with that.

what I did …I tried researching a shunt…but I never found the values for a resistance that would make it work so I simply took out the old 30A ammeter from the old dash, drilled some new mounting holes in the new frame of the new dash cluster and insulated it from ground….works perfectly

if you decide to do this…BE SURE there is no grounding to the ammeter. Isolate the two posts form the metal as toyota has done with the plastic insulators on the 30A gauge

 

[bj40man]

Very smart indeed. I can vaguely remember that the holes in the dash are different, correct? So in order to install the old ammeter you had to re drill them, right?

 

[bj40man]

Never mind, I can see it in your pictures! THank you for such a great explanation!

 

[knuckle47]

Yes, look at the posts in the 1st photo…they are too wide on the new dash…. Just also look out for the circuit board on the back If you re-drill…

 

[knuckle47]

Trust me when I say this….the guys on the forum have been living, breathing, talking guidance instructors for me on several topics.

‘’if I can pass something along. It makes my day….really !

 

[bj40man]

Trust me when I say this….the guys on the forum have been living, breathing, talking guidance instructors for me on several topics.

‘’if I can pass something along. It makes my day….really !

Thank you! My cluster is even more complicated as it is a 24v system.