I just bought my first volvo, a 1993 940 Turbo. After looking under the hood I noticed a couple unplugged harnesses, a disconnected vacuum hose, and an uncovered nozzle coming from the braking system. I was wondering if someone who was familiar with these cars could take a look at it, and possibly tell what they are, and whether they are unplugged intentionally. I included some annotated pictures, let me know if any additional information is needed.

PS, I know the vacuum lines are cracked, I have replacements coming in the mail. And the greasy bits will be pressure washed soon.

Thank you in advance.

 

first picture, looks like one of the sensors on the side of the head along there. there are three total sensors, the coolant temp sensor used by the fuel injection and ignition system, the anti-knock sensor, and the coolant temp sensor (CTS) used by the coolant temp gauge on the dash board. I forget what order they are in. a disconnected CTS would result in an check engine light and code (and very poor running). a disconncted temp gauge would result in the temp gauge flat not working. a disconnected knock sensor would mean if you got bad gas or were running hot and pushing hard and your engine starts knocking, it wouldn't know to retard the ignition and could cause internal engine damage like cracking pistons.

2nd picture, yeah, probably the charcoal vapor system

3rd picture, that is indeed the master cylinder, and those fittings are for the various brake circuits, and should be connected to the ABS module, but its quite possible that particular one is a bleed valve or something, otherwise you would HAVE NO BRAKES.

4th picture, looks like it plugs into the windshield squirter pump directly under it.

 

Hi, I know it´s 7 years later but... did you ever find out what the connector in your first picture was for? I found the same one yesterday in my ´94 940 and took almost the same picture as you. Thanks in advance!