Plug identification and brake help!

zerostar2410 · Aug 13, 2018

Ok, got a couple questions.

Picture below.

1) What is the square plug on the right side of the picture? has a pig tail that doesn't connect to anything. Comes from firewall behind upper intake. When I unplug, cant start bronco until its plugged back in.

2) What is the red plug right above it? It has 2 females and 1 male plug that doesn't go to anything. Also comes out of firewall behind upper intake.

3) Trying to get my hydroboost and explorer swap working. Power steering works but the brakes still spongy. Brake pedal is extremely slow to return to upright position after being pressed. I feel like Ive bled all the air out of the system but not 100% sure. Any suggestions? Power steering pump no longer foams or wines like it used to when air was in there.

Master Chief · Aug 13, 2018

Can only help with #1. Neutral safety switch/back-up lamp harness. Guessing that yours is jumped out meaning that you must not have a neutral safety. Follow this thread to see what I mean; http://classicbroncos.com/forums/showthread.php?t=245366

If it were me and it is indeed jumped out, I would replace the bad switch.

zerostar2410 · Aug 13, 2018

Master Chief said:
Can only help with #1. Neutral safety switch/back-up lamp harness. Guessing that yours is jumped out meaning that you must not have a neutral safety. Follow this thread to see what I mean; http://classicbroncos.com/forums/showthread.php?t=245366

If it were me and it is indeed jumped out, I would replace the bad switch.

SWEET!!! Thanks for the help. Now i need to figure out how to replace with the 4r70w.

anybody have any ideas on the other plug and the brakes?

mtp71174 · Aug 13, 2018

I think the other plugs were temp, oil and coil wires. This is I believe from the original configuration of the truck

zerostar2410 · Aug 14, 2018

mtp71174 said:
I think the other plugs were temp, oil and coil wires. This is I believe from the original configuration of the truck

So ignition, engine temp, and oil pressure? sounds about right.

Anybody have any idea on the brake situation?

Rustytruck · Aug 14, 2018

The red plug on the firewall you will need that hooked up.
Our Bronco vendors should carry that. it follows down the drivers side valve cover and hooks up gauges and ignition.

https://www.cjponyparts.com/scott-d...MIjPKGqe7s3AIVk8hkCh0FNQI6EAQYASABEgJxt_D_BwE

Rustytruck · Aug 14, 2018

As Far as the brakes I use one of those pump bleeders and a brake switch lockout tool. I have always had poor luck bleeding the Bronco brakes without pressure bleeding.

https://www.speedwaymotors.com/Moti...ke-Bleeder-Square-Master-Cylinders,33861.html

https://www.speedwaymotors.com/Speedway-Proportioning-Valve-Bleeder-Tool,296895.html

Skiddy · Aug 14, 2018

one more question on the brakes, how is your return ran

zerostar2410 · Aug 14, 2018

Skiddy said:
one more question on the brakes, how is your return ran

sorry for the sideways pictures. I dont know how to keep them rotated correctly.

Return is ran from hydroboost to power steering reservoir where the "T" is located down to one end of the cooler.

other end of cooler is run to the gear box (fitting on the right side). From gearbox back up to the hydroboost (fitting on left side).

zerostar2410 · Aug 14, 2018

Rustytruck said:
As Far as the brakes I use one of those pump bleeders and a brake switch lockout tool. I have always had poor luck bleeding the Bronco brakes without pressure bleeding.

https://www.speedwaymotors.com/Moti...ke-Bleeder-Square-Master-Cylinders,33861.html

https://www.speedwaymotors.com/Speedway-Proportioning-Valve-Bleeder-Tool,296895.html

not sure if this will work with my master cylinder type. I have the corvette style cylinder.

Rustytruck · Aug 14, 2018

If you continue to have problems especially if your brakes start dragging re-orientate that t fitting so the return on the Hydra-boost enters the cross of the T and the return of the power steering box runs straight through the long leg of the Tee fitting to the reservoir.

The way you have it plumbed some people have back feed problems to the hydro boost. there is very little flow from the return of the hydra-boost.

zerostar2410 · Aug 14, 2018

Rustytruck said:
If you continue to have problems especially if your brakes start dragging re-orientate that t fitting so the return on the Hydra-boost enters the cross of the T and the return of the power steering box runs straight through the long leg of the Tee fitting to the reservoir.

The way you have it plumbed some people have back feed problems to the hydro boost. there is very little flow from the return of the hydra-boost.

I’ll give that a shot. Might as well do it now before I start to have those problems or maybe it’ll fix my current one.

zerostar2410 · Aug 15, 2018

Another plug to identify!! the wiring in this thing is pretty bad.

Anybody know what this plug and green wire is? It seems like it loops back in on itself but i cant tell because its wedged behind the upper intake.

DirtDonk · Aug 15, 2018

Can confirm what the others said about the first wires. If this is the '72 in your sig then that's a connector in preparation for the upcoming addition of an automatic transmission to the options list.
The pigtail-to-nowhere with the two flag style push-on connectors would originally have run over to the steering column where a simple push-on switch was for the backup lamps.
If the Red wire is actually Red w/blue, and loops back on itself, that would have been for the neutral safety switch to interrupt the signal to the starter relay.

With an auto trans, both functions are on the side of the trans, hence being in the same connector.

Not sure about the last wire. It's abnormally large for an under-hood wire, and looks an awful lot like the ammeter wire, but that would have been Black w/yellow and under the dash.
I'm sure there is something basic I'm forgetting that would be under the hood, but I an't think of it at the moment.

Can you verify the color all along it's length, and check for any stripes?

Paul

zerostar2410 · Aug 17, 2018

Rustytruck said:
As Far as the brakes I use one of those pump bleeders and a brake switch lockout tool. I have always had poor luck bleeding the Bronco brakes without pressure bleeding.

https://www.speedwaymotors.com/Moti...ke-Bleeder-Square-Master-Cylinders,33861.html

https://www.speedwaymotors.com/Speedway-Proportioning-Valve-Bleeder-Tool,296895.html

Are you still in El Monte? Can I borrow your $74.99 pressure bleeder? I have a harbor freight type but not sure if it works correctly. I’m in Whittier and still can’t figure these brakes out.

Now when I apply pressure to brakes I feel pressure building and pushing back slightly.

zerostar2410 · Sep 26, 2018

Found another plug. What is this for?

DirtDonk · Sep 26, 2018

Can't tell it's overall shape, or location, but the only two that I know of that look even remotely like that are the connectors for the brake-warning lamp and the windshield washer pump.

From the factory, I think the brake warn lamp plug is white, and the washer pump connector is black. But the washer connector has a slightly trapezoidal shape, where the brake warn plug is more oval.

Both are on the driver's side, but the warn lamp is down along the frame and I'm pretty sure comes down from the firewall/wheel well area in the back, while the washer would travel along the inner fender skirt down to the front area behind the headlight.

Got a pic from another angle?

Paul

zerostar2410 · Sep 26, 2018

Here ya go. The plug is located under the drivers side floor board. Looks to be tied into the tail light harness. I don’t have the original fluid bottle so maybe that’s why the other end of the plug isn’t around?

DirtDonk · Sep 26, 2018

Nope, that's for the brake warning lamp on the dash.
You can tell by the shape and color, but the wire colors are the dead giveaway. Purple-ish is for the brake warning lamp.

It's part of that harness, but surprising it's tucked up that far back. But it probably still reaches the area around the H-block if you still have one? Would be up on top of the frame rail, nearabouts behind the shock and spring towers.

Paul

zerostar2410 · Sep 26, 2018

DirtDonk said:
Nope, that's for the brake warning lamp on the dash.
You can tell by the shape and color, but the wire colors are the dead giveaway. Purple-ish is for the brake warning lamp.

It's part of that harness, but surprising it's tucked up that far back. But it probably still reaches the area around the H-block if you still have one? Would be up on top of the frame rail, nearabouts behind the shock and spring towers.

Paul

What exactly is a brake warning light? Every time I push on the brakes 2 lights on the cluster illuminate green. Aren’t those brake warning lights? I do not have the H-block (proportioning valve?) on the frame area anymore. It’s up by the master cylinder.

I can’t seem to find the other portion of the plug to plug into.

Plug identification and brake help!

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