[pvcar]

how would i go about testing my alternator for working condition??

 

[bear]

Well, one way to do it without a VOM is to have the engine running, roll over the lites, preferably at nite so you can see any difference, between idle and 1500 RPM in the brightness of the lites, also your amp gage will show you also if the alternator is putting out amps also. With a VOM, engine not running, check the battery voltage, it should be just above 12 volts, with the engine running about 1500 RPM the voltage should be between 13.8 and 14.2 volts. HTH.

 

[greensmurf20]

a local auto place can test your alternator, most for free. most of the time, its the voltage regulator if your still running the origional style points type regulator.

 

[pvcar]

well my problem is i jus put a new used alternator in my gt its condition unknown and at idle my amp gauge is at dead 0 but with headlights and stereo at idle its in the negative and it only goes a little above the positive while driving with the headlights and stereo on, im thinking it could be the alternator and/or regulator i may jus do the delco conversion it may just be easier then fixin the origanal.
thanks for ur help ill try the test with my vom tommorow.

 

[ConreroGT]

It could possibly be the regulator. A good upgrade is one of the modern alt's that OGTS sells. It's internally regulated so you can ditch that ugly stock regulator box.

 

[pvcar]

yah but it sounds cheaper actually if i did it my slef since those alternators run abou t40 or 45 bucks and i got every thing else so i dont really wanna spend 120 at ogts unless that was my only option although i did think about it.

 

[soybean (R.I.P.)]

pvcar, did you see this thread? http://www.opelgt.com/forums/showthread.php?t=248&highlight=alternator+upgrade Do you have the original alternator on it or an aftermarket? If you still have the original on there and it's shot, this would be the time to upgrade it. Also on Ebay I've seen alternators for early model Saabs that crossover for Opels. Just a couple of thoughts. HTH, Jarrell

 

[pvcar]

well i guess im gonna have to do the conversion tommorow since this afternoon right when the rain started coming down hard my battery by this time has fully drianed its self and my car just shutsdown in the middle of a long up hill section that people do 60 up even in the rain, well i got someone to bring me one of those porta jump thingys and i stuck that under the hood and hooked it up and used that as my battery too get me home, it worked great. well if anyone has any good tips that havent been coverd on the conversion im open for them, once again this site is a life saver.

 

[Scott McDonald]

The conversion is easy, but if you just need a replacement regulator, I have a new one I never used.

 

[pvcar]

im pretty sure it was something in the alternator that was shot, today i called up my local alt. shop and got a 7127 for 40 with connector, went home to try and test fit it and found i had to remove some of the a/c bracketry, so i did this and found that the lower pivot part of the hosing hits on the mounting bracket how have u all gotten around this problem i dont rember reading about it as being a problem i still beed to get the upper mounting arm but thats a job for tommorow, just wondering how all of u have done the lower bolt with this alternator to keep it from binding.

 

[soybean (R.I.P.)]

pvcar, check out post nos 5 (oldopelguy) in my previous post. There are 2 ways to solve your problem, both are discussed in that post. jimsky also discussed it in the next post (6). I used the JBweld (post 40) and drilled it out (alt) using the original bracket as a guide and made up the difference with 2 washers at the rear. Works great, no problems with fan hitting etc.. HTH, Jarrell

 

[pvcar]

yah what i figured id use is a piece of a trailer hitch ball the threaded part which is about a and 7/8 i think and jus turn it on my lathe till it fits then cut two pieces off stick in my drill press and drill the offset holes. one interesting thing i found out tonight i was using an extra lower alternator bracket to see were everything needed to be but then i go over to my gt and look at it and im like hey wait a minute that brackets aluminium on my gt and the other one i have is cast iron, i think they may have used a diffrent bracket for the a/c gt's then with the regular non a/c model. what do u all have cast or alum.??

 

[kwilford]

hey wait a minute that brackets aluminium on my gt and the other one i have is cast iron, i think they may have used a different bracket for the a/c gt's then with the regular non a/c model. what do u all have cast or alum.??

I have seen both, but I thought the aluminum brackets were GT-sourced, and the cast iron were from a Manta/Ascona. Or maybe the aluminum brackets are newer; I took a cast iron bracket off an engine that I was told was a Manta, but the attached transmission was definitely pre-71 (the old speedo angle drive and the early reverse switch), so that would pre-date the Manta. Maybe an older Kadett?

In any event, the cast iron brackets don't stick out as much from the block as the aluminum bracket. Perhaps that is why the alternator interfered with the bracket?

 

[pvcar]

well i no the cast iron one had a definent opel eblem on it and the aluminium one had no markings i could see its possible that it was an after market but it seems like the aluminium may be a better bracket to use ill see in the morning, i no that both of my gts the one the alternator is going into is a 1972 and im the second owner and thats the one with the aluminium lower alt.bracket my other parts car i could see that one having an aftermarket one on there do to how beat that engine was.

 

[kwilford]

well i no the cast iron one had a definent opel eblem on it and the aluminium one had no markings i could see its possible that it was an after market but it seems like the aluminium may be a better bracket to use ill see in the morning, i no that both of my gts the one the alternator is going into is a 1972 and im the second owner and thats the one with the aluminium lower alt.bracket my other parts car i could see that one having an aftermarket one on there do to how beat that engine was.

I didn't suggest that one was "Opel OEM", and the other was "After-Market". I thought that maybe the aluminum bracket was either GT or just later (post 1970), and the cast iron was either non-GT or earlier.

Whatever; if the aluminum bracket fits better, use it.

 

[greensmurf20]

i've seen both aluminium and cast on GTs, they are the only opels i've had. all but 2 of my cars have been extensively messed with before i bought them, the 70 and my 71 have both had cast, while the 72 engines i've had seem to have all been ali, one motor was from a manta as it had the special finned ali pan.

 

[pvcar]

i found it better to use my cast iron one in the long run so i am using htat with two steel busings with the offset mounting holes drilled in them, my qustion is how do u hole thos bushings from moving while ur installing the alternator i think im jus gonna put a couple tack weld s on them so they dont move during install, what has been done befor to get past this bump in the customization to the new alternator?

 

[pvcar]

ok finally got my gm alternator in and mounted, wasnt as easy as i thought it wouldbe but was pretty easy, i had to use an upper bracket off a late chrysler car i believe it was, it works great, lower mount is perfect fit as well i could use my same belt and did not have to get a bigger one. thanks fro all the help again.

 

[GTJIM (R.I.P.)]

Alternator Tester

Found this neat wee device recently for testing alternators and batteries while in the car. Just a set of probes attached to a box with LEDs on it - the lower three lights are for a battery test with the motor off and the upper three for the alternator while the motor is running. The lights just indicate voltage in the circuit being tested - one light on is low voltage = poor
all lights on is "Strong Output". A cheap easy way to reassure oneself.
No makers name is visible but it came from an auto supply shop.