Engine fuse keeps shorting
 

The 15 amp fuse labeled engine fuse keeps going out on me. I'm able to start the car for about 15 seconds and then it will die. I took out the adaptronic ecu and it still does it. Im kind of clueless where else to look. All the wires that go to the cooling fans look good and so do the wires that go to the back of the coil packs. It use to run fine, so I'm assuming a wire somewhere got either ripped off or melted. Can someone give me some pointers on where to start? And would a bad coil pack cause this? Thanks in advance

Engine fuse controls the main relay and fuel pump relay. Start there.

Thanks savington. I can hear my fuel pump kicking on and priming when i turn the key. Would a bad fuel pump relay still be able to blow the engine fuse? Also if you could point out where the two relays are in the car, that would be greatly appreciated.

I don't remember where they are on a stock car, sorry. Mine have been relocated. I think they are up under the dashboard, unfortunately.

Sav is only part right.

The 2000 wiring diagram shows the engine fuse feeding the coil side of the Main Relay - not the switched side (not the fuel pump relay).

The engine fuse also feeds the Ign coils, O2 sensor and airbag module.

Start with the easy stuff - pull the main relay, it's in the engine compartment fuse box. Turn on the ign (the car won't start) see if the fuse blows - if it does the problem is between the fuse and the relay, O2 sensor or airbag module. If it does not blow it's the relay.

With our modded cars my bet is the O2 sensor wire or the sensor itself.

^ so the engine fuse doesn't have anything to do with the fuel pump relay? Ill be taking my exhaust apart soon to check the o2 sensor wires, these wires could possibly have melted because they are right by my down pipe. Also would a bad o2 sensor make the engine fuse pop? I figure it would just make the car run like crap since its not having a good signal to monitor the afr's.

**Disclaimer - I'm using 2000 Wiring Diagrams, your 1999 may vary**

The engine fuse will not blow with a fuel pump relay problem.
The fuel pump relay is fed by the Fuel Inj fuse (30amp)

Does the fuse still blow if you just turn on the ign and don't start her up?

Did you check the Main Relay?

The O2 sensor from the point of view of the engine fuse is just a heating element - if it is contacting the inside of the case when powered - voilà

Could still be the coil pack or airbag module (note the airbag module is in self test when started up) . Try unplugging them both and see if the fuse still blows - add them back one at a time until it blows.

Good luck - at least it's not intermittent so you'll know when it's fixed.

yes i see. Thank you very much baby car, for your inputs. Would you be able to tell what else the engine fuse is connected to? I'm not so great at reading wiring diagrams.

Engine Fuse is connected to:

1) Cooling Fan relay coil side (not switched side - not cooling fan itself). Near engine bay fuse box.
2) Main Relay coil side (not switched side)
3) Ignition Coils
4) Oxygen Sensor - front and rear
5) With A/C - Condenser Fan relay coil side (not switched side) behind driver's side headlight
6) Airbag control module under the dash
7) Data Link Connector - Engine bay driver's side
8) With Daytime Running lights - DRL Control Module under the dash

All of these wires on a 2000 are Black/White

wow. thanks for the checklist. I appologize for being kinda blunt on how to check to see if I have a short. So do I just go and check all of the black and white wires connected to these and make sure that one of them isn't hitting a ground? Or what is the proper procedure to taking care of this problem?

Step 1 - Does the fuse blow with the ign on but engine not running?

a) If Yes - Disconnect everything on the list and try again.
Does the fuse still blow with ign on? If Yes, you have eliminated all the components as the problem - but not the wiring up to them - start tracing wires for a short. If No, start reconnecting one at a time until the fuse blows.

b) If No - Disconnect everything on the list that is not required to run the engine and start the engine.
Does the fuse still blow? If Yes, you have eliminated all the components that are now disconnected, start tracing the wires to the still connected items. If No, start reconnecting one at a time until the fuse blows.

WOW greatly appreciated barbycar!