# Alernator replaced, but still popping a fuse...



## alank2 (Dec 29, 2006)

Hi Everyone,

I replaced the alternator because it was having issues. I'd turn the car on and it would stay at a low voltage and then pop up to 14 V after an engine rev or period of time. The new alternator hasn't done this and also seems capable of running the A/C and fan when in drive and not moving so that is an improvement over the old one too.

I was really hoping it would fix my fuse popping problem, but it hasn't. I put a fresh new 10A fuse in the "Meter and Gauge, Warning lamp, ASCD, Turn Signal lamp, Backup lamp, Hold relay, Seat Belt timer and buzzer" and went for a little drive.

I tried to get it to pop by using my turn signals or backing up, but this did not do it. It was just driving along about 500 yards from my previous turn when it popped. I always know because the tach dies and the battery light comes on.

I wonder WHY the battery light comes on. It seems to be changing intensity as well just driving. The schematic shows the battery light connected to the alternator and the the fuse that pops. I guess once the fuse is taken out it finds some ground (probably what is causing the pop) and electricity flows from the alternator through the light to ground, lighting it up.

I've compiled a list of things according to the schematic that this fuse connects to so I can figure out the likely culprit.

Any ideas of the following which might be more likely to have a fault allowing it to go to ground?

oil light
charge light
brake light
washer light
sensor light
door light
fuel light
alternator (voltage regulator)
tachometer
seat belt timer and buzzer
ascd relay
ascd main switch
back up lamp switch / inhibitor switch
warning relay (light chime)
hazard switch
combination flasher unit
sensor hold relay

Thanks,

Alan


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## alank2 (Dec 29, 2006)

Hi,

Knock ASCD relay, warning relay (light chime), seat belt timer and buzzer off the list. I unplugged them and it still pops the fuse.

I went for a small drive and got right down the block, make a left turn, and it popped.

I replaced the fuse.

I went for the same small drive and got right down the block, this time I still go left but I do NOT use the left turn signal. Still pops at about the same place.

Tired for tonight; I will keep battling this tomorrow!

Going to disable the back up lamp switch/inhibitor switch and sensor hold relay to see if it still pops them.

Beyond this nearly everything else goes through the main 1I Harness which powers the instrumentation. I was hoping to find the issue before I have to try this.

Thanks,

Alan


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## alank2 (Dec 29, 2006)

Hi,

*Figured it out.* It was the combination flasher! I noticed after unplugging the hazard switch (which feeds the combination sensor when turned off) that it stopped popping fuses. I put the hazard switch back on, popped fuse. I looked downstream from the hazard switch and there was the combination flasher. Has itself a nice direct lead to ground and a malfunciton could certainly short circuit and pop a fuse. I put in a new fuse, put the hazard switch back in, pulled the combination flasher and did a test drive. No pop. I then went ahead and ran a wire with a 5A fuse so that the turn signals and hazard signals are connected again, but without the combination flasher. I could use the turn signals, but they won't flash so I would have to manually flash them if need be. Drove it some more, still no pop. I bought a replacement flasher at a local parts store for $13 and put it in place. Turn signals blink again as expected. Drove it a bit and still no pop. Put everything else back together again that I had disconnected. Drove it some more, still no pop!

I think I have it fixed and am happy to have the issue behind me!!!

I wonder if the bad combination flasher was causing my startup low voltage from the alternator issue too. The alternator L terminal comes from this circuit that also fed the combination flasher.

P.S. no way I could have traced all these circuits without a service manual. Having a service manual for is a MUST.

Thanks,

Alan


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## Faja (Aug 31, 2009)

That's a great job of trouble-shooting.......... WELL DONE!!!


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