90s Ford Van/Truck Gurus; What's the Connector For

First up.yes I need to get a wiring diagram but I figured somebody in the hive might know.

On my 1990 Ford E250 Camper van there is an unused yellow three pin connector down by the parking brake and dimmer switch.

I am thinking this might be for the trailer brake controller.

If anyone knows please enlighten me.

Back in '90, I'd lean towards no, but that's just from installs on my own stuff back then. Never added a controller to either of my ford vans way back when. 
YMMV

Yellow connectors are typically for the Supplemental Restraint System (SRS).

I thought that the trailer brake connector was a 4-pin affair.

In reply to wae :

They are 4 pin so that's what confused me.

As both Ford and Coachman built the vehicle I often find things I would call odd.

Pictures help.

APEowner said:

Yellow connectors are typically for the Supplemental Restraint System (SRS).

Would a 90 have even had that?

In reply to Ranger50 :

I will take one later today.

03Panther said:

APEowner said:

Yellow connectors are typically for the Supplemental Restraint System (SRS).

Would a 90 have even had that?

Hmm. Now that you mention it, probably not.  Perhaps I shouldn't be posting in the middle of the night....

APEowner said:

03Panther said:

APEowner said:

Yellow connectors are typically for the Supplemental Restraint System (SRS).

Would a 90 have even had that?

Hmm. Now that you mention it, probably not.  Perhaps I shouldn't be posting in the middle of the night....

93 or 94, for the 150, and 98, for 250-up, started the airbags.

In reply to APEowner :

Before about 15 years ago, I'd never owned a ford as new as a 1990. So I wasn't real sure. But my first thought to the post was "a '90 van wouldn't be advanced enough to come pre wired like that"

But stranger things have been found in autos!!!

On a 2006 E150, that sounds like the connector for the seatbelt sensor. Dovetailing off the SRS idea. I know it probably doesn't have airbags, but does it have an indicator for seatbelt?

or if it has ABS, the "abs test connector?"

this website may help. 
https://charm.li/Ford%20Truck/1990/E%20250%20Van%20V8-302%205.0L/Repair%20and%20Diagnosis/

In reply to Dneikirk :

You did pick up on it being a 1990, right? Has more in common with the '72 I had, than an '06 

Poo In forgot to take a picture. I will try tomorrow.

My 1991 F250 had a similar connector.

It wasn't for a brake controller from what I could tell but I never bothered to figure out what it was either.

In reply to 03Panther :

I did pick up on that, which is why I linked a wiring diagram for 1990 I completely blanked on the chassis changing in 1991 though!

In reply to Dneikirk :

My phone didn't show the attachment at the time. Just the info on 06 wireing. 
As I said, I've never owned a '90s ford, but I know 06 is not comparable. 

Up until about 97-98, Ford often produced one wiring harness for a vehicle.  It had all the possible options in the harness, so if maybe yours doesn't have cruise, or a tach, or something like that, it may be for an option that yours wasn't equipped with.  It was a nice thing because if you wanted to add an option you could just scavenge it from a junkyard and it was plug n play

After 97-98, they did the frustrating thing of having a modular harness.  You got a basic harness that only covers the options you currently have, so adding something like power windows means you have to buy the harness and snake it to all the doors and back to the fuse panel.

Possible clutch switch?

Is it a round yellowish but clear connector?

Ok here is a photo

Ford used that aryle connector in the 1970s, but that looks rather aftermarket.

That screams aftermarket accessory, especially given the wire gauge is rather large.

It may well be part of the RV harness or someone had some accessories installed.

Thanks.