Rb25 Alternator Not Charging Battery

[KerrodR33]

So a while back my car died from a weak battery and it turned out that the standard alternator was on the fritz and eventually caught fire.

I replaced the battery and bought a brand new Bosch alternator and now it's not charging the battery at all. Everything is connected correctly but I had noticed that the battery light would not come on when turning the ignition on or not come on at all.

I removed the dash and checked the bulb to see if it had blown but it hasn't and I also tested it with known working bulbs but the light would still not switch on.

Could this be the cause as to why my alternator isn't charging as it is part of the charging circuit? And if it is, how do I fix it?

Cheers guys

[89CAL]

Yeah, you need to check the R terminal on the battery, I think it has something to do with excitation and the battery light on the dash. I'ts been quite a while since I've done altenators

The R terminal should have battery voltage on it from memory. Part of the excitation of the altenator. So if there is no voltage here the altenator will not generate power.

This is from memory so not 100% sure if I'm right

[KerrodR33]

Excuse my ignorance but what is the R terminal? I know of side, top and L terminals but never heard of R?

I have started the car and used a multimeter to check voltage at the battery while it is running and can see that it is not charging and that is all I have measured.

[KerrodR33]

Sorry for double post, but no idea how that pic ended up in my post haha embarrassing.

[89CAL]

there is your large terminal on the altenator, obviously goes to your battery to charge it up. Then there is a small wire that goes to a stud that is your R terminal. Seen as there was a fire its possible that the R terminal wire might have got fried

[KerrodR33]

Oh of course the R terminal on the alternator! I thought you were talking about the terminals on the battery haha my bad.

May possibly have fried the wiring. Do you know how much for that to be re-wired would cost and if it is an extensive job?

[evox]

Have you tried testing the alternator using a multimeter while the engine is running? It's good to test an alternator this way because you will know the if your alternator is generating enough voltage to charge your battery. Try this http://automotivez.net/bad-alternator-symptoms.html they have a video of how to test the alternator. Also, check your wiring. Some of it might have been damaged and causing a bad ground to your electrical system.

[GTR-N1]

I had to replace an alternator last Wed with a brand new one. JLM unfortunately didn't have a a spare one for my 3l VQ30 Maxima.

This new alternator lasted just 350Km before it carked it too. Battery wouldn't charge this morning. Warranty replacement is happening as we speak.