DIY Regulator Rectifier, car regulator, radio shack rectifier

[dq212]

Hey all,

My buddy and I just finished wiring up the custom reg/rect from various instructions using the Chrysler regulator and the Radio Shack rectifiers. I also have some other mods to go with it.

My bike is a 75 XS650.
Pamco ignition.

I also have that tiny (cigarette box sized battery mod that some of you may have seen out there .8ah) I know, there are many opinions about this thing, but I'm determined to try for now at least. It's kick-only.

So with this setup it appears to be working well mostly, but when I turn the switch on, it drops dramatically, down to about 8V.

When I give it some throttle, it hops right back up. It's hard to get a solid reading but at times it seems to be over-charging, up to about 15V. I saw some other posts that said to clean some connections and the main fuse. It's all new and clean.

I also did the test for drop at the switch. What I don't know is if that test in particular should be done with the bike running or not. With the bike off and light on, the drop is significant. Several volts.

The instructions out there were not totally clear to me. But I'm trying my damnedest. This is what I did...

1. nylon screws on the top two and bottom right on the stator.

2. using the existing black wire still connected(via nylon screw), wired it to a 10amp fuse ( didn't have a 7.5 handy) and fed that to power after the ignition switch.

3. The green wire runs up into the regulator as does the now fused (formerly black only wire).

4. wired up the rectifiers as per the instructions going to the battery on the positive and the other to ground.

5. Stator yellow wires go to the rectifiers as well.

One part I got confused by was the use of the existing black wire. As I understood it, it stays put, connected to an in-line fuse and then to power, but now simply has a nylon screw at the stator to unground it. Is that correct?

The other questions are whether anyone out there knows that if by using that tiny battery, the massive voltage drop at the key switch turn is to be expected, and if there is any other obvious reason that I'm getting the occasional high recharge at 15V?

I know this is a thoroughly reviewed topic, but I haven't seen it done with this configuration. Any help would be greatly appreciated.

Regards,

-dq

 

[pamcopete]

The drop to 8 Volts or so is due to that tiny battery. It just can't carry the load. If the battery voltage goes up to 15 Volts, then that is a sign of excessive drop across the ignition switch, but you would not get "several Volts" drop, so you must be doing something wrong when measuring that. I don't understand your statement "with the bike off and the headlight on" Does your headlight not go through the ignition switch? In any event, you want to measure the drop across the ignition switch with everything on, engine can be running or not. To check for proper operation of the regulator, check the voltage on the load side of the ignition switch, because that is the voltage that the regulator "sees". It does not regulate the battery voltage per se.

 

[dq212]

Thanks Pete.
Yeah, I meant bike not running but all the lights on. My headlight is hooked up off of the main power after the switch, with it's own toggle switch set to off while kicking it.

What do you think should I do if I can't sort out the 15V situation? New switch, new battery, check/re-wire connections? Better ground. All of the above? The real question is, in your experience, what is the most likely culprit of high recharge? Wiring or component?

I'll check it all out as per your 'load side' suggestion. I'll get some pics too to see if that can help me explain the set-up.

Thanks a million for the quick reply.

 

[dq212]

So here is a diagram of what I have set up.
I was gonna post a picture, but it looks too much like spaghetti.

I checked all the connections. Everything appears to be intact and clean.

At idle, testing at the battery, I get a reading of 12.6 - 12.9 V.

When I rev up the engine 1/4 throttle, it goes up to 14 and change.

At 1/2 throttle, it skyrockets up to 15 and above.

Do you think that this setup may necessitate using a capacitor?
Is it possible that a failure to ground elsewhere would have this effect? (headlight, tail light...etc)

Any suggestions would be appreciated.

Thanks,

-dq

 

[XSLeo]

Well, I have the same set up on my 75. The three wires coming from the stator, yours may look yellow but they are white.
Any way your diagram is ok. No switches, tail light or brake lights but ok. I might hook the wire from the black wire brush and the brown wire from the reg together then to the fuse. This way the fuse protects both the reg and rotor.
As Pamco pete said the reg reads the power at the brown wire connection. So if your main switch is dropping two volts the reg thinks the battery is two volts low and is trying to charge the battery, even if the battery isa fully charged.
One thing you can do to test your switch is to with the bike running and use a jumper wire to bypass the switch. This will put full voltage to the reg and it then can read the brown wire voltage without the switch voltage drop.
Another thing is to chech the vlotage at the battery and compare it to the voltsage at the brush with the nylon screws. If the brush voltage is not at or near, like .2 or .3 volts less than the battery you have a problem between the battery and the nylon screw brush. Most often the main switch.
On the volts jumpping to high at high rpms it sounds like a possible weak ground. Not bad enough to find with the ohms meter but weak enough to not work under the vibes of high speed running. It took me a while to figure that out when My 75 would blow headlight bulbs. The ground from the headlight went back to under a bolt on the frame. It checked fine with the ohms meter but the bolt wsn't as tight as it should have been as well as I didn't get the frame clean enough. At speeds the connection was poor enough so it was intermittent. This lead to power surges in the headlight and kept blowing the bulbs.
The ground on your reg may be doing this. Good enough at low speeds but intermittent at high speeds.
I like this diagram. It shows the basic pints and seperate reg and rec like your bike was. It also has the later reg/rec in a box, As well as the later TCI. Just swap the boxes around. The reg you are using wires in just like the later reg/rec.
Leo

 

[dq212]

I'll give it try tomorrow.
Thanks so much to both you PamcoPete for all the info.

 

[dq212]

Hi there, so I went through all the wiring as recommended and the bike is now recharging and doing pretty well.

With my set up though, I was wondering, is it possible/advisable to add a capacitor to the mix to help that tiny .8ah battery and Chrysler reg/rect? OR is it better to just do a whole PMA thing if I'm going to bother?

Thanks for all your help though, looks like I'll get that thing on the road before the bad weather.

-dq

 

[XSLeo]

With your stock alternator with the Chrysler/Radio Shack reg/rec it will be fine with just the tiny battery. The battery won't take much abuse so having a spare handy at all times is a good idea.
Will adding the cap help extend the battery life? I doubt it.
If you want a longer lasting battery get a better battery. One a bit larger. I like my Ballistic 8 cell battery , about half the size and weighs about 1.7 lbs. And it can crank the starter just fine.
THey have a smaller battery for scooters. Very small and light weight.
Leo

 

[dq212]

I'll look out for it. The bike is running/starting much better now with some ignition timing adjustments.
Now, I have some mixture screw trouble on the left side! I'll have to start an new post once I get the specs of my setup, been awhile since I was in the carbs.

Thanks so much for all the info, extremely helpful.

-dq