10 Amp Engine fuse on an 89 FI

[gunnerw]

OK, reconnected the white wire and it ran fine. I removed the white wire the reconnected the "T" connector with the red/blk and wht/blk wires and it ran fine. As soon as I reconnected all three it started and 10 sec later it died. Do I need to make wires to test the the red/blk and wht/blk separately?

[dalebwilson]

Ok. Re-Connect the alternator wires one at a time and crank after each.

[gunnerw]

I took the alternator to AutoZone and had a friend test it on their machine. It passed all 4 tests. Here is the results.image.jpg

[dalebwilson]

Ok. Your alternator may be overcharging or have a short circuit. Take your alternator to your local parts store and have it tested. In the interim, re-connect the 3 alternator wires one at a time and crank the engine after each. This could point to which circuit is faulting.


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[gunnerw]

No. I shut it off after 5 mins. It then cranked right back up.

[dalebwilson]

Did the fuse blow again?


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[gunnerw]

Ok, I did as you said, disconnected the alternator and replaced the fuse. The car started and ran for 5 minutes

[dalebwilson]

Remove all temporary wiring. Disconnect the 3 alternator wires, white, red, brown. Put a new 10A fuse in under the dash Make sure your battery has a good charge. Start the engine and see if the engine will stay running.


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[gunnerw]

Dale,

I tried the test you suggested. I ran a wire with a inline 10a fuse from the blk/wht wire to the 12+ on the battery. As soon as I connected to the battery i could hear the main relay click. I cranked the car but it would not start. I tried this a couple of times. I had a friend with me and to demo the problem to him is removed the temporary wiring and put a new fuse in the engine slot on the fuse box. As soon as i cranked the engine it started and ran for about 1 minute then died. We both did smell something burning. No flames or smoke the the slight smell of smoke. The only non standard equipment in the car is a radio that was added years ago..

Any new suggestions?

[gunnerw]

I havnt done the test yet but I will before I do anything else.

[dalebwilson]

Be cautious that Blk/white is the same wire color of the "Engine" circuit. Did you ever do the test with the alternative 12V supply?

[gunnerw]

I have looked around the engine for unusual wiring changes. The photo shows two modifications that I can see. One wire yellow/green cut at on time and the re-crimped. The other is a black/white wire coming from the wire harness just under the wiper motor and is spliced in to a smaller black wire that goes to the connector under the ignition coil. Then the black/white wire travels to a connector into a smaller wire (same size as the wire under the ignition coil) that lead to a small square box on top of the distributor. I looks to me like both small black wire were at one time the same wire that would have run from the distributor to the coil. That would be my guess. Any ideas?image.jpg

[dalebwilson]

According to what you told me, the main relay appears functional. Per the Haynes diagram, the engine fuse only supplies power to the main relay.

[gunnerw]

I can check with the previous owner. I did notice one location where two wires were spliced into one with electrical tape but dont remember any wire colors. I'll check that when i get home. What other devices run through the engine fuse? I just installed a new fuel relay and fuel pump do you thing that could be it? It was a pretty straightforward process to install both.

[gunnerw]

Are you confidant the bench test I did proved that the relay is good?