[brknsl]

Hi all,
I took out the intake and radiator and found out there are several connectors that are not connected to anything... Note that this engine was running with these connectors disconnected but I do want to figure out where they are supposed to go. (this is on a 1994 3000GT SL)

The first one that I would like to know is the left connector shown in the picture below. I know the right one goes to the IAC motor on the throttle body and they are on the same wiring harness.

The second one we have here runs across the plenum from the timing belt side to the throttle body side.

The last one I have here is the connector that is on the same wiring harness as the alternator connections.

Sorry that was a lot, but any help would be appreciated!

 

[white93gt]

The second one we have here runs across the plenum from the timing belt side to the throttle body side.

I believe the second and third pictured connector halves are for oil pressure sensor and switch, that plug together (with blue end plastic on each) and attaches to far left plenum mount bracket. See below picture of far left connector B-06. The middle connector B-07 should be 4 wire connector, for rear back injector operation. Far right connector B-08 (already mounted in your picture) is 2 wire connector for knock sensor.

 

[white93gt]

The last one I have here is the connector that is on the same wiring harness as the alternator connections.

Cant Make out number or color of wires in this connector, but it might be for A/C compressor safety thermostat, revolution sensor and clutch.
Also looks like the other halve can be seen in right side background, sort of in front of alternator belt pulley.

 

[white93gt]

The first one that I would like to know is the left connector shown in the picture below. I know the right one goes to the IAC motor on the throttle body and they are on the same wiring harness.

The left connector in first picture, looks to be connector for vehicle speed sensor. The ’94 speed senor should have three wires, 1 Black wire with white stripe, 1 solid Black wire and 1 solid Yellow wire. It would plug into speed sending unit at back side of transmission.

 

[striker3]

The last one I believe is the front bank O2 sensor, which I dont believe exists on the 94 SL if it has the federal emissions but the connector is still tied up in the harness.

 

[brknsl]

The left connector in first picture, looks to be connector for vehicle speed sensor. The ’94 speed senor should have three wires, 1 Black wire with white stripe, 1 solid Black wire and 1 solid Yellow wire. It would plug into speed sending unit at back side of transmission.
View attachment 303198

Thank you so much for all of the feedback. I will check it out tomorrow and hopefully find the other half of these connectors... I was truly a miracle driving this car back from the seller with all those connections off lol. Proabably gonna find more disconnections along the way too

 

[brknsl]

The last one I believe is the front bank O2 sensor, which I dont believe exists on the 94 SL if it has the federal emissions but the connector is still tied up in the harness.

Phew, one less connector I have to worry about haha. Thank you man!

 

[white93gt]

The last one I believe is the front bank O2 sensor, which I dont believe exists on the 94 SL if it has the federal emissions but the connector is still tied up in the harness.

The fed spec connector is a 4 pin straight connector. BUT you might be correct if it's a Cali spec car, because they do use a 4 pin square connector.

 

[white93gt]

Thank you so much for all of the feedback. I will check it out tomorrow and hopefully find the other half of these connectors... I was truly a miracle driving this car back from the seller with all those connections off lol. Proabably gonna find more disconnections along the way too

You’re welcome for feedback, I’m betting when driving back your oil pressure gauge and speedometer wasn’t working.

 

[brknsl]

You’re welcome for feedback, I’m betting when driving back your oil pressure gauge and speedometer wasn’t working.

Hmmm... Now that's weird... I believe the oil pressure gauge was working when I was driving. It is some digital aftermarket gauge so I'm not sure if that changes the wiring or anything like that. I can confirm that speedometer was actually working BUT the tachometer was not working. Ugh, the previous owners/mechanics really made a mess with the wiring. I am like really really confused right now 😣

 

[white93gt]

Hmmm... Now that's weird... I believe the oil pressure gauge was working when I was driving. It is some digital aftermarket gauge so I'm not sure if that changes the wiring or anything like that. I can confirm that speedometer was actually working BUT the tachometer was not working. Ugh, the previous owners/mechanics really made a mess with the wiring. I am like really really confused right now 😣

OK .... An aftermarket oil gauge might have it's own wiring or even a actual pressure tube to gauge. Also I couldn't clearly make out wire colors on what I thought might be speed sensor connector, so that might not even be for speedometer sending unit.

 

[striker3]

The fed spec connector is a 4 pin straight connector. BUT you might be correct if it's a Cali spec car, because they do use a 4 pin square connector.

That is for the left bank, which is the rear bank and the only one used on Fed spec cars IIRC. The right bank (front) is only used on the Cali spec cars but I believe the connector is still in the harness and would be the square connector.

 

[white93gt]

That is for the left bank, which is the rear bank and the only one used on Fed spec cars IIRC. The right bank (front) is only used on the Cali spec cars but I believe the connector is still in the harness and would be the square connector.

That's what is weird, prints identify both left bank and right bank as (front) in two of the illustrations for Cali and one other as rear . The first illustration identifies left bank as (front), then shows different connectors for Fed and Cali spec. So who knows when talking about O2 sensor connectors.

 

[striker3]

I think the FSM (page 113 in volume 2 of the digital copies for 92-96) means "(front)" as upstream of the pre-cat and "(rear)" as downstream for the individual banks, Left or Right.

 

[white93gt]

I think the FSM (page 113 in volume 2 of the digital copies for 92-96) means "(front)" as upstream of the pre-cat and "(rear)" as downstream for the individual banks, Left or Right.

That logic is as good as any I can come up with and is possibly correct.

However, in any case the O2 connector is only 4 pin square connector on California spec engines (per same page 113 you referenced). Federal spec engines use connector C-55, which is 4 pin straight connector. IIRC with fed spec NA engines the front bank O2 sensor wires come from trans side, runs inside of front bank injector shielding plastic and passes around/down by valve cover to O2 sensor on exhaust just below header. Which also makes me wonder if it’s actually O2 sensor wire, because in his picture wires for the square connector is clearly coming from low on chassis drivers side and running in harness with alternator wiring. Do you know if I got wire routing correct and what do you think about this?

 

[brknsl]

The left connector in first picture, looks to be connector for vehicle speed sensor. The ’94 speed senor should have three wires, 1 Black wire with white stripe, 1 solid Black wire and 1 solid Yellow wire. It would plug into speed sending unit at back side of transmission.
View attachment 303198

I checked the wire this morning and you were right! The connector in the first picture I posted is indeed for the vehicle speed sensor as you said. Somehow the speedometer still worked with that left disconnected... Or maybe I accidentally disconnected when removing the intake