Dash / Gauge Lights (1 Viewer)

[bj40green]

I can't see what is under the tape on the left side of the Ammeter connector but I inserted 2 red lines as how it should be hooked up.

The second part of your text is not clear to me. Maybe you can explain it again.

Rudi

 

[Bear Lake Cruiser]

Rudi, Here is a blow by blow as it leaves the battery. It comes off the battery post with a red wire that quickly turns into a segment of 16 gauge fusible link. Then comes the 18 inch 14 gauge loop. then back to the 16 fusible link material. Then the yellow butt connector which has black tape on the right side. Under that tape is the two ammeter wires and the fusible link material. Those two wires continue clockwise to two blue butt connectors, into my new inline 5 amp fuses and then into the main harness and thru firewall, and assuming the cluster and ammeter as their final destination. To the left of the yellow butt connector is a connector of the original fusible link, I have it taped as the locking tab is broken. The thick gauge White and blue stripe goes from that connector between my two new inline fuses and into the harness where inside it 'T"s one direction going to the alternator and the other over to the ignition switch for distribution. Some other extra wires I have coming of the battery post are the white one which runs the driving lights/headlights relays and a thick blue one that runs auxiliary power in the rear. And of course the starter cable. When I loaded the current draw way up with wipers, headlights, driving lights, stereo, emergency flashers, cig lighter, and heater motor at full blast, and engine off the White/Blue wire going from the taped broken tab connector into the harness got hot, my infrared thermometer showed 108 degrees max heat. When engine fires up and alternator supplies some current it seems to drop down ambient temp which was about 85 in the garage. Since the ammeter showed normal with the ohmmeter (almost a dead short), and it is wired as per wiring diagram I didn't know what else to do so I went onto my FJ60 and starting the installation of rear retractable three point belts which were not offered in 1984. That won't be so easy either!
Best regards,
Tom

 

[bj40green]

Capice!
Okay, see the picture below.
Take out that "old" piece of wire (marked orange) with the taped connector.
Connect the White/Blue from the harness to the Black Fusible Link wire and the Black wire to the Ammeter.
Connect the White/Blue from the Ammeter to the other side of the Fusible Link.
This is important otherwise the Ammeter will show reverse reading.

Part ll
Your test..... nothing wrong with that and the temperature. You're draining your battery at high speed and yes.... that creates heat.
The wiring in those Cruisers is on the tiny side. As soon as the engine is running and the alternator does his job, your temperature problem will disappear.

Rudi

 

[Bear Lake Cruiser]

Thanks Rudi, I will check out your recommendations and report back. Well aware of the undersized wire used on land cruisers after having 9 or 10 of them since 1970. I wasn't concerned about the wire getting warm.

On first glance to your recommended changes I think I am understanding that the fusible link (and 18 inches of 14 gauge) acts as a shunt between the two wires to the ammeter. Right now I have both ammeter connections on the downstream side of the fusible link.

When I put the connectors on the loop I did it in a fashion that I can take it out and hook up the fusible link back together quite easily.

 

[Bear Lake Cruiser]

@bj40green

Rudi, pure genius sir. Thanks for being patient and leading me through this. For the first time since 2009 when I got this rig I have an ammeter working. Even though the gauge is certainly not accurate I would guess that with all powered up and engine off, just a guess I would say -10 amp deflection. Running it is about +10 Amp.

So can I assume that if there was a longer fusible link or 14 gauge loop that it would increase the meter movement? After my cutting and splicing my fusible link lost an inch or two overall length.

Thanks again, this 40 is a fairly nice one and now that this is fixed all electrical problems are gone (knock on wood)

Tom

 

[bj40green]

@bj40green

Rudi, pure genius sir. Thanks for being patient and leading me through this. For the first time since 2009 when I got this rig I have an ammeter working. Even though the gauge is certainly not accurate I would guess that with all powered up and engine off, just a guess I would say -10 amp deflection. Running it is about +10 Amp.

So can I assume that if there was a longer fusible link or 14 gauge loop that it would increase the meter movement? After my cutting and splicing my fusible link lost an inch or two overall length.

Thanks again, this 40 is a fairly nice one and now that this is fixed all electrical problems are gone (knock on wood)

Tom

The fusible link is a safety device. It works as a fuse but it can handle a large run-in current before it burns up.
A fusible link should be 4AWG sizes bigger than the wire it is protecting. So if the White/Blue is AWG10 than the FL should be AWG14.
The length of the FL is not important. 2 to 4 inches is OK.
Toyota made a design error or miscalculation whatever. That "loop" was figured out by mud-member @amaurer .
If you want to read all about it.... it's in this thread: -► Clusters, Gauges, Speedo & Odo meters
Yes it can be a few Amps inaccurate but now you have an indication what happens under the hood.

Please post a picture of the finished works for my archive.

Rudi

 

[Bear Lake Cruiser]

Will do for sure. I left in the taped plug as it changed the circuit none to leave it the black ammeter wire was spliced on the correct side of the fusible already and it was a good tight splice. I get 3/16 of an inch needle deflection at the tip of the needle. Perfecto, just like I remember my other early model year 40's being.
I'll snap a picture in a while.

 

[Bear Lake Cruiser]

@bj40green Here is that picture, not as sharp as I like but you will understand.
Thanks again for your help.

 

[bj40green]

Thanks for the picture. Can make one from the Ammeter showing pos. or neg. deflection?

Rudi

 

[Bear Lake Cruiser]

@bj40green The first one is at rest, nothing on. This meter centers slightly left of line, always did. The second engine running with lights, heater on. The third is engine off with all electrical components on. The battery is only a month old and was at full charge during these photos. It might be nice to have a bit more deflection to be a more noticeable. I have no idea of actual current going through the system I suppose I could wire my Fluke meter in series to see the actual amperage and adjust the 14 gauge coil length to true it up.

 

[cuencanolenny]

The difference between a pre '79 and '79 and later is the Ammeter.
On a pre '79 it's a 30-0-30 Ammeter. In this set up the full current (charge and discharge) flows through the Ammeter.
View attachment 1167332

On a '79 and later it's a 50-0-50 Ammeter. In this set up the full current goes through a fusible link.
View attachment 1167331
This Fusible link works also as a shunt resistor and the voltage drop over this link/resistor is used to get the Ammeter working.

Unfortunately the OEM fusible link has a design error but Mud member @amaurer found a solution for this.
View attachment 1167333

View attachment 1167334
In short.... you have to make a modification in the Ammeter circuit.

Rudi

Thanks for the link Rudi. I think this does answer a question for me though. I wasn't sure where the link and fuses were to be located. Of course on the diagram it looks like right behind the cluster. That made me think there were two fusible links, one by the battery and one at the ammeter. So if I cam understanding this correctly, there is only one, somewhere close to the battery.

 

[gcrump01]

Going back to post #35 - did you figure out what this plugs into?

 

[bj40green]

Going back to post #35 - did you figure out what this plugs into?

Nope, but looking at diagrams for the General Market.... L/R is used in the heater and A/C circuits.
You can find B/W wires in that same area. So my thinking is that it is for an option not installed on your Cruiser.

Rudi

 

[gcrump01]

It may be AC related. I have learned that my 1980 has the AC wiring built into the wiring harness. The plug pictured above was not plugged into anything when I got my truck. It did not have factory AC either.

 

[FMB787]

Hi,

i would ask how to make new wiring using this loop wire

SO which one of below ways i must follow :

or this

 

[bj40green]

This one

EDIT: Here is the modification inserted in the wiring diagram.

Rudi

 

[FMB787]

Thanks Rudi for the advise ,

i went to local market and couldn't find 16 gauge fusible link i found (20-ga. - 0.5 mm) only
So is it OK to use it ?

i will connect first end direct to alternator , can i connect the other end to fuse box( when the ignition is on ) instead of direct wire from battery ( the Amp connected all the time )?



my engine is SBC 305 with 140 Amp alternator will this effect any thing ?


why i am asking those questions because i dissemble all the harness and put them in a bag and after few years i couldn't find it , now i am making my own harness.

 

[bj40green]

This set up is based on the stock 50Amp alternator and 50Amp Ammeter.
The White/Blue wire from the alternator and to the battery is AWG12.
The (Red) stock Fusible Link is 4 AWG sizes bigger thus AWG16.
This Fusible Link is there to protect your harness in case of *?$%! problems.
If you're using a 140Amp alternator...... You have to totally re-calculate (the thickness) your wiring.
So if you're going to use AWG20 it will burn out as soon as there is a big charge or big load in the electrical circuit.
Also the 50-0-50 Ammeter circuit will not function correctly.
My advice: Forget the Ammeter and shunt modification.
Install nice fat cables and install a voltmeter like this

Rudi

 

[wngrog]

Hey guys.

I am going to install a new @Racer65 cluster into my 68 FJ40.

My harness is completely toast so I am wiring everything individually as I add it back.

My alternator is an internal regulator for an FJ60 on a 2F

So, what would be the proper way to wire the 50 amp gauge from the later model Cluster to my alternator? I don't have a fusable link anywhere so I'd rather use a regular fuse if possible but will buy whatever I need to make it work.

 

[Gun Runner 5]

Sorry to change the subject but ... has anyone removed the metal curtains that surround the illumination bulbs? Has anyone removed the horizontal divider that separates the engine instruments from the speedometer. It appears these items would have a negative effect on the illumination of the cluster.
Thanks