Author Topic: Alternater only works above 4000 RPM (Read 9052 times)

burn_your_money · « **Reply #15 on:** November 11, 2006, 04:45:12 am »

My two alternators are identical, the one works perfectly but has the wrong mounting points.

I'm definitly not understanding this rotating bit, hopefully it is in my bentley when I find it.

Actually now that you mention it, at idle and when I rev the engine below 4K, the battery indicater light does dim

Hillshy · « **Reply #16 on:** November 11, 2006, 06:43:47 am »

burn_your_money,

check this link:
http://images.google.co.uk/images?q=tbn:rq0s9fCQwhGz2M:http://www.electricboatparts.com.au/persistent/catalogue_images/categories/100001

The atlernator in the picture should be more of less he same as your's with 3 mounting points(bosch), 2 on the front half (pulley end) 1 on the other/rear/diode end). see the 4 brass coloured screws in the chassis, if you were to remove these then you could if needed, rotate the rear mount 180 deg clockwise to change the mounting config, depending which side of the engine the alternator sits.

You have an alternator that has different mountings,

is this how it differs? what was it off?

ps the pulley also has to come for the mod?

hillshy

Hillshy · « **Reply #17 on:** November 11, 2006, 06:54:39 am »

is your alt like this:
http://www.iat-usa.com/fpdb/Images/al1057b.jpg

then the hand thing wont apply, I think our vw engines came with at least 2 different types.

Hillshy

burn_your_money · « **Reply #18 on:** November 11, 2006, 01:12:18 pm »

I have this style alternator

The differance between the 2 is where the 2 mounting holes are (the ones that share the same tab) One hole is threaded, one isn't. The threaded holes are opposite on the trannys so the rear mount doesn't reach. I know I could just use a normal bolt and nut but I don't think the belt will stay tight.

burn_your_money · « **Reply #19 on:** November 11, 2006, 04:40:00 pm »

The 4 screws that hold the 2 pieces together are stripped to hell, what's my best option? Getting a reman? Drill them out and then hope I can use vise grips to remove them?
I got my spare apart easy enough

Thank you all for the help so far, it's very much appreciated

Hillshy · « **Reply #20 on:** November 12, 2006, 02:17:44 am »

Hi burn_your_money,

you say that you could if needed secure it with a normal bolt but the belt might not stay tight, if you managed to mount it with a normal bolt i'm not saying you should but if you did and you wired it up, if it works then a least you would know 2 things for sure.

1st) the new alt works fine, as all problems have been cured.
2nd) the old one was faulty for sure, as per the problems stated.

you would then be able revert back to standard mounting Alt as nothing has been changed, then using parts from to new Alt to fix the old Alt were not in vein, that's probably the way i'd go.

decesions decesions eh :?

good luck tho!
Stu

burn_your_money · « **Reply #21 on:** November 12, 2006, 07:15:50 am »

I actually tried that last night but one of my spares, the mounting point at the top where the bolt slides through is too small to accept the bolt. I don't want to use a smaller bolt incase of damaging the threads on the mount.
I then tried my other spare but the lower tab with the 2 holes in it is closer to the alternator body so the lower bracket does not fit in. It was an extremely frustrating night.
I do have 3 other alternators though, one is siezed, the other is almost siezed and the other is on my rabbit which is parked for the winter. The rabbit one works but has a differant style connector. The 2 siezed ones are the same style as what I need too

Hillshy · « **Reply #22 on:** November 12, 2006, 08:26:32 am »

Hey mate,

i guess you don't have any other options but to rebuild the present one, fustrating i know, but to look on the bright you seen to have nuff parts/spares to make one good'en without havin to pay out shed loads of cash.

i've also had a $hitty week, tuesday eve, a bus ran my wifeee into another car so she so ended being sandwiched between it and another car, the whole front end of our car(subaru turbo wagen) both front wings, 2 front doors and both front alloys were bashed to £uck, currently undrivable, thankfully she and my 3 yrs old son were ok apart from shock but ok otherwise.

thursday, while sitting down for dinner, heard a gushing sound followed by drip drip drip splash drip drip,i look up and see water leaking from the ceiling above, an upstairs water pipe had burst!!! could have waited until after dinner. ended up joing to hell n back to sort that mess out.

what a week :lol: , gota shugg it off and lol about it...

Hillshy.

burn_your_money · « **Reply #23 on:** November 13, 2006, 01:21:12 pm »

Wow man, your week sounds way worse then mine. I'm very glad to hear that your wife and son are alright

Pity about the car though. Was the upstairs waterpipe one of yours or a tenants (aparetment building style)?

I ended up buying a rebuilt alternater. It set me back $180 but it comes with a 3 year warranty. I tried to rebuild mine but the screws were so rusted in there that they stripped so I just gave up and got a rebuilt.

The only thing now is my tach won't start working until the engine hits 2500 rpm. I could drive all day and not have a tach but as soon as the RPMs exceed 2500 it works perfectly. My driving style has me shifting around 2250 so sometimes I don't get a tach for quite a while

jtanguay · « **Reply #24 on:** November 14, 2006, 02:45:41 am »

sometimes i gotta blip my throttle to get my tack sensor to work too. if the engine has ran in the past while sometimes the tach kicks on after a few seconds of being started... if you blip the throttle above 2500 does it kick the tach on? is that the case or no? if not then what a weird problem... better connect a multimeter up to the tach wire and see whats up... maybe the rebuilt one is messed?

burn_your_money · « **Reply #25 on:** November 14, 2006, 01:22:42 pm »

Yes if I blip the throttle above 2k the tach kicks in right away. I just find it weird because my other jetta tach would actually work while cranking, so I knew the cranking RPM.

Hillshy · « **Reply #26 on:** November 14, 2006, 01:29:24 pm »

evening all.

Burn y money, lucky the pipe was inside my house, My bro had fitted shelfs into my sons room and hit a water pipe he caused the leak, but to be fair you would never have guessed there was a 15mm pipe hidind behind a fitted wardrobe, all sorted one and i'm start'n to see the funny side to it, still really pissed about the car tho

, glad to hear the alt is sorted.

jtanguay- your prob seems similar to mine, but then i did the rev mod, that is mentioned on this site, it seems the alt needs about 20 sec's to start after the engine has been run, then it jumps into life and is fine from there onwards.