want to knw wat can cause an alternator to ctch a fire

smallz · Postby **smallz** » September 4th, 2011, 10:29 pm

k..... as mentioned.........
today after a do it yourself project of an engine wash with purple blaster concentrated cleaner...... lil water left behind in distributor etc.... managed to get it out an engine started etc...... i get a backfire from d air intake.....decide i'll jus have someone chk it out for me.......
ten mins later........ i see d alternator smokin up den lighting up.........

enlighten me.... besides dat i need a new alternator an a electrician.........

tanap · Postby **tanap** » September 4th, 2011, 11:54 pm

water not suppose to get in the alternator if so u suppose to blow the water out wit an air compressor

wagonrunner · Postby **wagonrunner** » September 5th, 2011, 7:29 am

tanap wrote:water not suppose to get in the alternator if so u suppose to blow the water out wit an air compressor

really? because those "engine wash" places don't do that, and vehicles start and drive out without any similar problems.

smallz · Postby **smallz** » September 5th, 2011, 8:32 am

wagonrunner wrote:
tanap wrote:water not suppose to get in the alternator if so u suppose to blow the water out wit an air compressor

really? because those "engine wash" places don't do that, and vehicles start and drive out without any similar problems.

well i was thinkin d same thing... car wash dont blow it out.....

Postby **Hook** » September 5th, 2011, 2:07 pm

What vehicle? I know there was an issue with Ford alternators up to a few years back stemming from a faulty alternator plug. Haven't heard of this in any Ford vehicles locally, but there's still a small possibility.

Are you certain that in washing it, no fluids containing flammables (eg. oil lifted off dirty engine during rinsing) got into the alternator?

rollingstock · Postby **rollingstock** » September 5th, 2011, 4:01 pm

Excessive water can cause arcing, and if it gets in the rectifier can cause a minor electrical fire. What vehicle is it?

smallz · Postby **smallz** » September 5th, 2011, 5:00 pm

its an ae91 corolla wit 16 v efi.......

Postby **Hook** » September 5th, 2011, 5:33 pm

OHO! Could just be one of those rare water damage incidents like RS pointed out.

You in the mood to open that mofo for a post-mortem?

SOMETIMES, with the older Toyota alternators, the ceramic insulation on the diode pack flakes off (yeah, the build wasn't particularly robust). It's possible the water caused it to arc (alternator voltages sometimes get up in the 20's or higher BEFORE rectification and regulation, but I've never measured the current at that point).

But this is the first time I'm hearing about an alternator fire on one.
If/when Toyota alternators fail, it's usually without that kinda fanfare and fireworks lol

Get yourself some 10mm and 8mm sockets and a good phillips head screwdriver and see if that's the case. It's likely once flames hit it, it can't be repaired, but it'll be good information to have.

rollingstock · Postby **rollingstock** » September 5th, 2011, 6:35 pm

Scene the 'fireworks' with different brands before, somewhat rare but not impossible, it happens that's why you need to protect it when doing an engine wash, worst yet men use pressure washers that will allow water to penetrate vulnerable parts.

jblCROWN · Postby **jblCROWN** » September 6th, 2011, 12:23 pm

my cousin had dat problem same car like yours ae91 after he wash d engine

tanap · Postby **tanap** » September 6th, 2011, 10:24 pm

well d place where i does wash my engine de man does blow mine engine with an air compressor when he finish wash it then spray wd 40 i sure is d rectifier an diode burn if the coil burn well then is bess u replace the whole alternator save u trouble an time. if u cant get the original den u have to use other that have almost the same line up an amperage it u lookin for a good electrician from south pm me i will give u a contact number.

*edited*
Translation:
"Well, the attendant at the place where I get my engine washed, usually blows off the excess water with with an air compressor when he's finished washing it, then he sprays with WD40.
I'm certain your problem is a burnt rectifier an diode. If the coil is burnt, well then it's best you replace the whole alternator to save you trouble and time.
If you cant get OEM parts, then you'll have to use something compatible in terms of fitment and current tolerance and if you're looking for a good electrician from south, PM me, I will give u a contact number."

smallz · Postby **smallz** » September 9th, 2011, 11:26 pm

k. so d problem was in fact it got wet n lil remainders of grease etc got inside an lit up causin d whole jan jat...............
wasnt in any way repairable... couldnt het a direct replacement anywhere so i had to rebuild it.... works like a charm nw.............

rollingstock · Postby **rollingstock** » September 9th, 2011, 11:54 pm

^ glad to hear you got it sorted out.

To clarify though it wasn't grease, most likely old oil deposited, do you have any engine leaks, past or present? It would be a good to state for other users who may decide to do an engine wash and faces the same problem.

smallz · Postby **smallz** » September 10th, 2011, 12:32 pm

i stand corrected... yup.. oil an all d watever else it had lying around ... some got in an eventually d end result was it go kaboom...........
dont try it at home.............