80 series locker wiring

[Capriblue45]

I am getting to wiring the factory lockers on the 140 and I have a question for the electrical experts. There is a wire running from the center diff lock dash light to the controller and the indicator switch for the center diff lock and on to a ground source. Can i trick the controller into thinking the center diff is locked by grounding this wire permanently or can I add a rocker switch in place of the diff lock indicator switch? I hate automotive wiring, my least competent skill set. I don't want to let the smoke out of the controller as they are crazy expensive on the web.

Thanks all

 

[DaveInDenver]

Can you post a better picture? I have a 1994 and 1996 EWD, neither of which looks identical to yours. The 1996 is closest.

On it the purple wire that runs parallel from the combination meter goes to the ABS controller.

The other indicator on the 1996 EWD I have is the transmission position, it seems to be used by the ECU and CDL relay in some sort of logic. Does the 80 series require you to be in neutral or park to lock the CDL maybe?

Electrically what looks like is happening is the lamp itself is controlled by the CDL indicator switch but the condition of this circuit must turn off the ABS?

If this is the case then wiring it hard to +12V or ground would presumably permanently put the ABS into one state or the other. Which I couldn't say but I it looks to me like high (+12V) would be ABS normal/on and grounded would be ABS off.

You could use a switch to select but it would need to be a double throw that lets you toggle the common terminal between the two states. If you just switch one, either +12 or ground, and let it float it the other value the ABS controller might not sense it correctly. You sometimes need to actually provide both voltages.

 

[MountainGoat]

My 1995 80 Series can lock or unlock the CDL on the fly in high range with the CDL switch. When you engage low range in the transfer case it automatically locks the CDL. When the CDL is locked the ABS turns off.

 

[DaveInDenver]

My 1995 80 Series can lock or unlock the CDL on the fly in high range with the CDL switch. When you engage low range in the transfer case it automatically locks the CDL. When the CDL is locked the ABS turns off.

Yeah, a parallel path to engage the CDL with the 4L circuit looks absolutely plausible.

This is a side question since Mike's original question I believe relates to the ABS.

FWIW, this is the page I'm looking at in the 1996. Junction <I 6> below the CDL lamp ahead of the CDL switch looks to me like the state sense for the ABS.

 

[Capriblue45]

No ABS on the truck. These are the factory locked axles, magic dial and control module out of an 80 series that I have put under my 60. I am also using the 60 part time manual transfer case so no need to interface with an 80 full time case. The power for all the diff dash lights come from a 10 A fuse that is hot in run.

 

[DaveInDenver]

No ABS on the truck.

You mean the donor didn't have it? That would make it a 1991/1992, but then you wouldn't have lockers, right?

I don't see any reason other than to switch ABS for that wire.

I may, though, misunderstand what you're trying to do. You have a non-CDL t-case and want to tell the ECU something? The CDL indicator is downstream of the CDL motor and relay, which are controlled long before the lamp taps under the meter.

If it's just the ABS input grounding though 10k might work to do that. If you do not have an ABS computer then it doesn't matter, leave it unconnected but terminate things so that junction can't short to ground unintentionally (e.g. don't leave bare wire exposed).

 

[Capriblue45]

The donor had it but I am not using it on my 140 build. I will ground though the resistor per your advice. Thanks for the help.

 

[DaveInDenver]

This might help. This is the 1992, which shows the two paths with and without ABS. The CDL relay without ABS appears to not use the first level contacts and switch 12V to the two contacts as soon as the CDL switch is turned. That may also be the case with a manual transmission. Toyota doesn't show what happens to <I 6> in the without ABS case so it probably is a wire to nowhere.