90 tsi alternator not charging battery

[SICK SOCIETY DSM90]

Okay so my hot wire on alternator grounded out and now with a new battery and new alternator belts fuses and relays and still will not charge the battery. Does anyone have a good diagram to rebuild system or is there something im over looking. Just trying to figure out a solution to get this car back on the road. Any suggestion is welcomed and ty. Oh the car is all stock with all new maintance completed.

 

[1990TSIAWDTALON]

Are you sure ALL of the fuses are good? Did you check the ones that come right off of the positive terminal and also the BIG 80 or 100 amp fuse in the passenger side fuse box in the engine bay? IF all of those are good you could TEST by runnig a wire (BIG wire, not some little speaker wire or anything like that) from the alternator to the battery positive straight shot to see if it starts charging, but that is bypassing all other things in the wierd circuit that they have. Also make sure that the alternator is grounded good. I blew my 80 amp fuse and seatbelts, headlights, radio etc quit working. I replaced the fuse and then had to buy a new alternator also but i went with a 96 Galant that puts out 90 amps which is much better, no dim lights under load or when the blinkers are on. I have a Factory Service Manual but I am at work right now. Also check the voltage AT THE ALTERNATOR LUG to see if it is in fact putting out 13.5-14.4 volts, maybe it is just not getting to the battery which would narrow problems down. Just stuff I would do to check mine.

 

[4g63t]

+1 on it being the fuse that is in the corner of your fuse box. You have to unbolt it to replace it.
Just to be crystal did you replace the one in the top right of this pic?

 

[SICK SOCIETY DSM90]

the fuseable link in the top right still in contact and test out okay the only one i didnt replace is the alt relay that no one seems to have.

getting charge from alternator fuses are good just not making it to battery. If running a power wire and put a fuse so do not mess anything up would it send the power to the battery or is there another part to the system that would cause it not to work.

 

[1990TSIAWDTALON]

And you actually only have to LOOSEN those bolts (10mm I believe) and pull up to remove that fuse and replace it. I completely removed mine then figured that out....felt stupid.

Well this is just my take on it. I am a old school Chevy guy and new to DSM's too but on the Camaro's I build the alternator wire goes straight to the starter solenoid which is also attached directly to the positive of the battery, so in theory I say you could run a wire directly from the alternator right to the battery and charge away. I did say I was new to DSM's so ANYONE, correct me if this is a bad move but it works for Chevys, they go straight to the battery via the connection on the starter solenoid. You would obviously want big heavy guage wire for this and a ring terminal preferably soldered on each end, but a crimp connection should work too. MTC. If it were me, I would TEST this with a temporary wire and just see what happens. I see no way you would hurt your alternator as it just goes thru the fuse then to the battery. Maybe run an in-line fuse if you feel you need to and since those big fuses have bolt holes in there terminals anyway you could bolt one in. It really sounds like a fusible link/fuse is toast is all tho.

Thinking for a minute, have you tested for voltage at that fuse? Would be a good test.
And Orielly's had my alternator fuse on the isle with other fuses, just had to look hard.

 

[SICK SOCIETY DSM90]

Okay so problem fixed the fuse did not look to be bad but was blown on the side of the fuse. 3 dollar fix with new fuse thank you for the replys.

 

[1990TSIAWDTALON]

Glad to help when I can. I had the same experience on my car so I thought I could. Very glad she is charging again!!! If you ever have to replace that alternator, do the 96 Galant swap. It is a bolt on upgrade to 90 amps and works great. Not a single thing is different.

 

[SICK SOCIETY DSM90]

ya ive heard that i just went with replacement since everything is stock for now. Plan on building her up soon. Well time for the track see what i can muster out of her.

 

[1990TSIAWDTALON]

Post your track results.I would like to compair as I am building to and have not had it to the track yet because they aren't open here yet but will be real soon. Best of luck to you!!!

 

[Kswgsx]

I'm having a problem where I replaced the alt with a 90 amp one and I replaced the 80 amp fuse with a 100 amp fuse and the fuse keeps blowing

 

[DSM1G90]

Very, very bad practice to increase the amp size of the fuse due to an increased amp usage ALT and not do anything to the vehicle's wiring to match it.

Must want to have a car fire when doing this practice.

Using higher amp ALTS in a circuit made for the smaller ones creates higher resistance loads which will knock out the main fuse (breaker).

You really have to regauge the wire harness made for higher amp draw, otherwise, car fires can result if the main can't let go due to the higher resistance loads.