10 Amp Engine fuse on an 89 FI

[gunnerw]

Does anyone know why the 10 amp engine fuse would keep blowing on an 89?

[dalebwilson]

The fuse is drawing too much current. The engine fuse supplies power to the main relay coil. If the coil is weak or failing to ground, that could cause the fuse to blow. Check wiring integrity first and then consider the relay.

[gunnerw]

Dale is the main relay coil mounted on the quarter panel just behind the left headlight?

[gunnerw]

I red somewhere that there were problems with wiring running under the battery box. Could that be it?

[dalebwilson]

Yes

Dale is the main relay coil mounted on the quarter panel just behind the left headlight?

[dalebwilson]

I have not experienced a failure there yet....but like you I have read that there is a large multi wire connector in that area that can corrode and cause problems. Wouldn't be a bad idea to remove the battery and take a look.

I red somewhere that there were problems with wiring running under the battery box. Could that be it?

[gunnerw]

Well I have pulled the battery and the coolant over flow tank and saw no chaffing, burn or any other problems with the wiring.. I pull the relay and I am having a hard time finding another. Here is what is looks like. With a fresh 10A fuse the engine will start and run for about 20 seconds the die. Any ideas on how to check the relay or where I can get another?image.jpg

[Damkid]

Repair question don't belong in the general discussion forum

[dalebwilson]

Bench test the relay by applying 12V+ to the blk/white and 12V- to the black. Test continuity between white/blue and yellow/black.

[harpon]

Is that what that is? a relay?

to what? I noticed that dangling near the battery, and some rust on my '91-

are you talking otherwise about a fuse in the main fuse box?

Does the circuit run through the fussy-ble links? maybe shorting there.

[gunnerw]

The fuse I am talking about is a 10A fuse listed as "engine" inside the car on the fuse box. I replaced the fusable links with hard fues. I'll bench test it as suggested and see what i get

[Movin]

Did you mean the car started , blew a fresh fuse and died, with the relay pulled out ?

[dalebwilson]

Is that what that is? a relay?

to what? I noticed that dangling near the battery, and some rust on my '91-

are you talking otherwise about a fuse in the main fuse box?

Does the circuit run through the fussy-ble links? maybe shorting there.

Yes....thats the main relay and it should be mounted on one of the bolts that the coolant resorvoir is attached to. Without the relay functioning, your car doesn't run. The 10amp engine fuse supplies power to the relay coil and the EGI fusible link supplies power to the relay contacts. With the ignition switch in the run or start position, the relay supplies power to the fuel delivery system. If the 10amp fuse continues to blow, the circuit is overloaded due to a bad relay or possible shorted/grounded wire.

[gunnerw]

Movin: Yes the car will start and run for about 20 seconds the it blow the 10a fuse and dies and will not restart.

Dale: I am still looking at the wires to see if I have a grounded situation. I am having a hard time finding a replacement relay. I even searched by the part number on the relay (Denso 056700 8550) Autozone and O Rileys cant seem to find anything. Do you have any idea where to find this part?

[dalebwilson]

You may need to try finding the relay at a Ford or Mazda parts counter. May be an OEM part that is not available through the chain stores.


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