ecu fuse keeps blowing
 

My 1998 2.5TL keeps blowing the 20 amp ecu fuse when i try to start it the car will not start in fact you dont even hear the starter spin dose anyone have any ideas?

See my response to your other post. There is no 20A ECU fuse. The ECU is on fuse 39 a 10A fuse, Lower LH corner of underhood fuse box. Security system could disable the car w/ the starter cut relay.

You need a shop manual to help you find components and trace your electrical problem.

good luck

looks like texas handled this in your other post..:lock:

bad news replaced the switch because there was no power at the starter when turning the switch this was not the problem.
i traced the black/wite wire from the switch and found that it goes to a relay before the starter.
this relay is not closing i removed it from the curcuit and tested it it works fine i also traied another relay and the car dose the same thing.
If i use a volt meter to test the voltage going to the coil of the relay with the relay out of the curcuit i get 12 volts but once the relay is installed this goes to .2 volts.
there are two wires on the coil of this relay one blk/green the other yellow/green if i leve the relay in the circuit and measure between the blk/green and the car chassie i get 12 volts the yellow/green comes from the security unit assy under the passenger side dash.

My 2.5TL manual doesn't show a blk/wht wire going to the cut-out relay, rather a blk/grn wire supplying power to the relay for the starter solenoid and for closing the relay. Following may be wrong. You need a wiring diagram for your vehicle.

For the wiring diagram I have, the relay is controlled by grounding not power supply. Ground is supplied through the security system and AT gear position switch. Have you tried shifting to N for starting?

If you have power to the relay, check for ground. If it's missing, supply a ground and see if car will start. If yes, then you just need to trace the missing ground fault to the relay.

No need to repeat your post at multiple sites. Stick w/ this thread.

good luck

Looking back at your posts, I see you have a 2.5TL. The wiring diagram I have should be correct. The diagram shows the blk/wht wire going to the under dash fuse/relay box, then a blk/grn wire to the starter cut relay. This relay is under the dash, just to the outside of the cruise control box.

I suspect your problem is related to either the security system or AT gear position switch not allowing ground to the relay. The ground to the cut relay is a yellow wire to the security control unit, and a gray wire from security control to the AT gear position switch.

good luck

i found the security system and the gray wire i did a continuity test between where the gray wire connects to the security system and ground and the connection is good for both park and neutral so it seems the problem is the security system.

Thanks texashonda.

make another ground from the ecu case to a ground, do it anyway, its good for every ECU

My ecu fuse blow every time I start my 98 TL 2.5 what should I look for?