How can this car start without a starter relay

Maintenance/Repairs
1

UPDATE: solved below

Anyone with car knowledge out there can tell me how on earth a car (96 Taurus) can start without a starter relay?

Clues:

  1. the lock cylinder had recently been broken by car thieves, and now the car starts and runs without a key (I have a new cylinder waiting)
  2. there are no wire modifications (none seen) in the engine compartment, not under the fusebox there, not under the dash nor under the steering wheel column.
  3. curiously the car has been running without a PCM relay too, not sure why that would have been removed by the thieves, but apparently a car runs in safe mode when it’s removed.
  4. I’m using no temporary jumpers when starting it
  5. thinking maybe I mis-read the fuse box diagram, I removed every relay from the fuse box. It still starts and runs.

In my mind it should be impossible to start the car without the starter relay! Obviously, though, there has to be something allowing it. Like a good mystery, it’s hard to let go. I’ll probably put the two relays and a new lock cylinder and leave it. Any clues and insights would be welcome though.

2

How are you able to start the engine?

Tester

3

Turning the bezel where the key is inserted (just added a video). It works with or without a key (for now).

4

I don’t see how the engine can start without the starter relay.

The circuit goes from the ignition switch, to the park/neutral safety switch, to the starter relay, to the starter solenoid.

Tester

5

Exactly! I thought I knew at least a little about car mechanics and electrical. But this one stumps me. I suspected the PCM might be involved since the thieves took that relay. But the PCM would not be powered even if it could send a signal to the relay. And looking online the PCM doesn’t connect directly to the starting circuit anyway.

6

There’s no starter relay on a '96 non-SHO Taurus. It’s a relay for the MLPS switch. Here’s the wiring diagram:

96 Taurus Non-SHO
96 Taurus Non-SHO981Ă—696 44 KB

There’s only a starter relay on '96 SHOs:

96 Taurus SHO
96 Taurus SHO951Ă—687 55.9 KB

3 Likes
7

Hey. Awesome. That’s probably it. It didn’t specify in a fuse diagram. Thanks! I had considered if the solenoid could be activated with ignition voltage, but the Chilton manual wasn’t showing it and Chatgpt said no… Could you say whether it has a PCM relay or not? There wasn’t one in mine. Or if you have a link? Thanks.

8

Relay 10 is the EEC (Electronic Engine Control) module. That’s not a PCM module as this doesn’t technically have a PCM. Check out your owner’s manual if you still have it or search for it online.

1 Like
9

The bigger question to me is WHY would anyone try to steal a 96 Tarus?

2 Likes
10

Old cars don’t have immobilizer systems, they are easy to steal.
Same for Hyundai and Kia vehicles.
Most are soon abandoned or crashed, any car is suitable for those activities.

3 Likes
11

It’s good practice for the newbie 12 yo car thieves.

1 Like