80 amp fuse Keeps blowing

I have a 1996 Tacoma 2.7L. Truck is completely stock with no modifications. The other day I replaced my alternator. Bearings in the old one went out and noticed it quit charging the battery. Ordered a new one off Amazon that is a 60 amp DB Electrical brand. Once I started to take the old one off I noticed that the connector that goes on the stud of the alternator had broken which is why it quit charging. I cut the wire off right behind the connector to leave as much wire as possible for a new one. Unfortunately when I got a new end and went to connect it to the new alternator I had zero slack in the wire and didn’t like that. So I got some 10 gauge wire which is slightly smaller than original which I’m guessing is 8 gauge and put a 4inch or so splice for the existing wire to the alternator stud and at first connected the wires by trying to twist them together and tape them up. Did that cranked the truck dove it for about a 1/4 mile battery light came back on then everything quit. Dash lights and gauges. Got back to the house popped the hood and the 80 amp fuse was blown. Went and bought 2 more fuses (just in case) tugged on where I “twisted” the wires together (or so I thought) and pulled right apart. Thinking this was my problem for the fuse I reconnected the wires with a wire nut and taped it up with electrical tape nicely. Got everything hooked back up and fuse replaced cranked the truck it idled for about 1 minute and as I was about to shut the hood it died. Looked back at the fuses and 80 amp was blown again. Can anyone tell me what could cause it to short out? Bad alternator? Exposed wire? Also sorry for the long post but I’m new to the Tacoma world and didn’t want to leave out any details just in case.

 

Sounds like you've got a path from +12V to ground. Is the wire hooked to the back of the alternator securely?

Can you get pics of the whole repair?

 

Welcome aboard new member

 

Pics always helpful. 2. Get rid of that damn Amazon alternator. 3. Use the correct gauge wire. I’ll assume the old alternator was the original one,if so, there’s a reason the oem one lasted 24 years. Welcome also.

 

I can’t get any pics at the moment. I’m going into work and won’t be in until the afternoon. But yes everything is tightened down and secure. I didn’t touch any other part of existing wire besides the very end.

 

I agree with all of that. Was frustrated with autozone at the time hence Amazon brand. I really don’t want to swap it if I don’t have to because it was a bitch getting it in there. And 10 gauge was the biggest wire I could find at Napa.

 

Break out the Meter .

Might just be your poor splice Wire Nuts are not for stranded wire solder and heat shrink .

If it is not a short a loose connection arcing can open the fuse

If your Battery was not charged via a battery charger it can take out the diodes of the replacement alternator if diode shorted it can cause your fuse to open .

Test if you have continuity from the alternator B post to ground that will confirm a shorted alternator

 

What should I have the meter set on and what kind of reading should I get? I’m not very good in the electrical department

 

this is a pic of what I did.

 

I wouldn’t use that type of connector but that’s just me your connection as far as I can see looks good I think the problem is with your alternator. It’s not uncommon for lower end alternators to have spikes and burn fuses, I always try to go with denso for all things Toyota. Not as economical but a longer lasting product

 

Update: I put a meter on the alternator with the truck off and disconnected from everything. Read a steady 62.3. Which from I understand after asking some local opinions is good. Got a 4 gauge wire and ran it from alternator to fuse box post and eliminated the old wire. Put new fuse in and cranked it and ran for about 2 minutes and then blew the fuse. Doing another test with the alternator unhooked to see if a fuse still blows.

 

Plkyone was right. Rigged a 50 amp fuse up and cranked the truck without alternator and truck ran and idled for 10 minutes with no issues. So I’ll be ordering another one. Most likely denso as suggested. Thank you all for the replies and help. I will post another update once new one is installed to let you know if I have anymore issues.