How hot should an alternator get ?

Post by **ELVIS** » 28 Jan 2008, 22:46

Just that when i was driving home the temp guage went got cooler and the stereo started cutting in and out , thinking maybe alternator belt had gone . checked belt and still there but body of alternator was WELL hot !!! gonna get output checked tomoz but im not holding my breath - you reckon its dead/dieing?

Post by **airhead** » 28 Jan 2008, 22:48

Sounds like you might have a dangerous short somewhere. Be very careful. Such a short set my van on fire and it was the luck of god I had a crappy fire extinguisher and a bottle of water to put out the fire. The alternator body will get warm. Thats why it has a fan, but very hot... no.

Post by **ELVIS** » 28 Jan 2008, 22:54

i only drive in the dark at the mo!

have lights on and fan most of time - 20 + miles each way . was thinking if alternator is fecked i am drawing current from battery and slowly discharging it - hence the needle dropping and stereo playing silly buggers due to not getting enough leccy

Post by **airhead** » 28 Jan 2008, 23:01

Yeah OK but if your alternator is getting hot its doing something and the electricity its generating is turning into heat. Unless its friction but then youd hear it making a noise. Check all your wiring very carefully. Make sure the wire going fromyour alternator to your battery isnt severed and shorting on something.

Post by **ELVIS** » 28 Jan 2008, 23:02

mmm, know what im doing on my day off tomoz. cheers fella

Post by **edoh** » 29 Jan 2008, 00:06

someone else says -
Check each part and the charging system as a whole before replacing components such as the alternator. Removing and replacing the alternator only to find out that the voltage regulator, battery, or a loose wire is the faulty party can be an expensive lesson. Your local auto parts store may now have portable diagnostic equipment that can be wheeled out to sniff out problems with the charging system. A service manual and multimeter go far in outlining test procedures for checking the charging system and components with a multimeter. Check alternator output itself. Check Voltage delivery at the battery. Check voltage regulator output..

if u av a tester -

battery - just standing - should read 12.5 to 12.8 volts = battery fine

battery - w ignition on n running - 13.5 to 14.3 volts = alt charging

outside these ranges will indicate probs - as above -

Post by **kevtherev** » 29 Jan 2008, 06:28

yes check the regulator bushes...sounds like they've gone past the wear limit

Post by **Syncro G** » 29 Jan 2008, 19:14

My Landy is currently having altinator trouble that sounds a bit like your simptoms, ie the radio keeps cutting out. I think what its actully doing to achive that is serging and overpowering the electrics rather than not charging it, because the headlights get MUCH brighter (they are in top form to start with so any extra light is worrying as it shouldn't be possable) and the ammeter goes off the scale at the same time, dip the clutch so the engine goes to idle and so the altinator stops making much power brings the radio back on and everything back to normal. Tipically mines an intermitant fault so its always working properly when I have a volt meter handy so have yet to get the proper proof - I'm not sure I want to know how many volts it takes to trip out the radio, probubly something near what it takes to blow every bulb on the truck! (with some little ajustments you can actully mod a vehicle altinator to produice around 100v fairly easilly aparently, or weld with it - not good for a normal wireing loom/battery). Think I'll refit last weeks broken altinator again in the next few days, should be fine now as I found a rather obvious short inside it - Should cost me a blob of solder. That one never actuly stopped charging properly, but the red lamp wouldn't go out!