Converting agenerator to an alternator

[garyloos]

I have a restored 72 SB convertible and would like to change over to an alternator. The generator is putting out what I assume is a normal charge when rpm's are up but not enough to keep the gen light from coming on when sitting a a light at night when the head lights and turn signal on. Also if I blow the horn it will not do anymore than groan unless I have the rpm's up.

Battery voltage is reading 12.6 not running and with engine running and rmp's up it reads 13.8.

I would like to find a complete kit with everything I will need.

Thank you for any help you can give me.

Gary Loos

[Weaponer]

You can get a complete kit at cip1.com but I don't think that will solve your issues. Some batteries will show a good value but under a load, they don't do well. Harbor Freight sells a battery load tester fairly cheap. I just bought one for $17 on sale. They may be still on sale. I believe that horns are always hot and they ground in the steering wheel to complete the circuit. Try disconnecting your horn and run it directly off your battery to see if it's your horn or a connection issue. As for the lights, every VW I've ever owned seemed to have the idiot light somewhat lit when the lights were on at an idle. I don't want to see you spend time and money on an alternator if you have wiring connection issues. I would try to unplug and plug in all connectors and if the connectors are screws or bolts, loosen then tighten. For the horn, pop off the horn button and see if you can clean anything with a scotch-brite pad.

[Ol'fogasaurus]

Gary, if your battery has much time on it, before you outlay the cash for the conversion I'd advise you to check things out is take the battery to someone who can put a load on it in order to check the battery's condition; e.g., a full charge, surface charge, dead cell(s).

What your battery says: 12.6 and 13.8 sound about right but it might be just an instant's reading. For instance: you start the car, the battery shows it taking a charge for a short time then the reading goes down to a fully charged reading. If the timeline for the charge the battery takes is too short of a time to normally replace the energy used to start the engine then your battery might be taking only a surface charge... not a full charge and needs to be replaced.

In the old days cars had an AMP meter to check those things (I have been told a shunted Volt meter will do the same thing) when the engine was first started. People have gotten away from gauges now days and rely only on the "idget" light.

Get the battery OK'd first then if it is OK then upgrade if you feel the cost is worth it (usually it is) but if the battery is bad and/or the rest of the system not is OK you will still have to deal with them after the outlay for the alt, stand, etc..

[garyloos]

Thank you Weaponer& ol'farsaurus for the replies.

I will have the battery load tested and see what it shows. Also will check all connections for the horn.

I bought this VW in 1995 and restored it and have driven it very little the last 10 years until this summer which I have driven it about 1,000 miles so far. I was going to sell it but decided to keep it. About five years ago I put this battery in it but do keep it an a maintainer during the times that I did not drive it much.It could be getting weak due to lack of use.

Thanks

Gary Loos

[Ol'fogasaurus]

We just replaced a battery on one of our toys for similar reasons. We had not used a trickle charge on it for various reasons and it failed in a very short (no pun intended) time.

Lee

[garyloos]

My battery has been in for several years so I took it the auto parts store and had it tested which revealed it was in tiptop shape. I was surprised.

[Ol'fogasaurus]

Great! One possibility out of the way.

One advantage to buying a whole kit; e.g., the alt, the proper stand, wiring, etc. is there is no questions (or shouldn't be) on matching components. More expensive as compared to used components but it is the unknown of what is being sold to you. Sorry to talk like that but sometimes sitting can cause formally used parts to not be as good as they were... and... there are people who are not always that honest. Also, there are at least two, if not three, stands one being for a generator, one for an alt (size) and I seem to remember that there may be a combination stand. The pullys I am not sure of.

Lee

[aussiebug]

If you have not already bought the alternator, you can try these simple tests to see if you have a generator or regulator problem...you've already eliminated the battery problem - congrats on keeping it trickle charged when not in use - that gives any battery the best chance of a long life.

www.vw-resource.com/generator.html

Also, check the ground connections (brown wires) in the car, and especially the battery chassis strap (both ends) and the strap under the tranny nose cone. ANY poor grounding can cause poor charging and poor operation of electrical items. The reason I say this is that your charging voltage - 13.8v is OK, but is a little on the low side for a VW regulator - they usually hold the battery charging voltage to 14-14.5v. A poor connection could be causing that.

As pointed out above, the horn is live on one side and grounded through the horn ring wire, a brown wires coming up the steering column. Often the connector ring under the horn gets dirty and causes a poor horn.

[garyloos]

Will check it out. Thanks