Coolant fan running non stop and possible wiring harness issues.

[KennyMcRae]

Hey guys, picked up a ‘98 legacy L wagon the other day. 2.2 5mt.  
 

Upon noticing the rear defrost and cruise buttons weren’t lighting up, I checked fuses.  Cruise fuse was popped.  But the rear defrost wasn’t.  I open up the fuse panel under the hood and notice at some point, the fuseable link had gotten REALLY hot.  It looked new, so I assume it was replaced.  But there’s burn marks on the inside of the cover.

The harness coming off it looks fine and nothing else looks fried.  However, I did notice when I was checking fuses under the dash that the Main Fan fuse was just missing.  So I put a 20a in and the passenger side cooling fan kicked on and won’t shut off.  Car isn’t hot.  
 

Everything is pointing towards the two wire coolant temp sensor.  My thought is that when that short happened (guessing some idiot put jumper cables on backwards) that it may have melted the contact inside the sensor and is telling the ecu the engine hot.  Going to check the sensor tomorrow morning.

Anyone have any ideas about the rear defrost and cruise not working?  The AC won’t kick on either (probably related to CTS) Anyone have a link to a FSM?  I’d be willing to buy an actual FSM as I tend to buy a lot of these 2nd gen cars.  I also have a 1998 Brighton 5mt.  
 

I also noticed a couple wires going nowhere near the back of the engine on top.  
 

thank you

[doublechaz]

I saw reference to an FSM in some guy's vacation pics here.

 

What does a scanner show about that sensor?

[KennyMcRae]

That’s the next step, I ordered the Xtool Bluetooth scanner so I can see live data.  

However, I did pull the relay for that fan from the fuse panel under the dash and the relay has a closed circuit all the time.  Popped the cover off and it looks melted together on that contact.  I put the sub fan relay in place of the fried one and the fan did not turn on.  So I ordered a new relay.

 

The rear defrost works, the bulb is just blown.  I’m guessing from when the jumper cables got reversed.

Im pretty sure the cruise control module is dead.  
 

I located enough PDF files of the FSM to print out all the wiring diagrams and most of the test procedures.

Thank you for replying.  

[doublechaz]

Neither mine, nor my parts car have cruise so I can't help there.  But sounds like you are making good headway.

[silverton]

On 12/11/2023 at 6:54 PM, KennyMcRae said:

The rear defrost works, the bulb is just blown.  I’m guessing from when the jumper cables got reversed.

Just one though huh?  You don't think it could be that the car is 25 years old and... well, how many bulbs you have kicking around that are 25 years old and still working?  If it's anything like the bulbs that were in the switches of my three year newer car, they're bulb #74.

[KennyMcRae]

On 12/13/2023 at 8:06 AM, silverton said:

Just one though huh?  You don't think it could be that the car is 25 years old and... well, how many bulbs you have kicking around that are 25 years old and still working?  If it's anything like the bulbs that were in the switches of my three year newer car, they're bulb #74.

Well, the heater control lights are all dead and the previous own said he had to replace the cluster.  The rear defrost switch bulb works on my other 98 legacy.  
 

I picked up a few relays for the fans and that fixed the original main fan issue.  I also got rear defrost and cruise switches.  Also snatched up a set of pleated leather door card inserts. Pick n pull is great.

Edited December 19, 2023 by KennyMcRae