For the 'Wiring Brains' in the forum, this is an untested idea proposal.

I sent a long letter to Dan at WolstenTech to see if their TDR-P product would be suitable for a time delay in our heavy-duty alternator set-ups. It sounds like this is a simple, cost-effective solution for the big-amp setups. It is basically a relay, with an adjustable timer to 'make' the connection after a delay.

When the fan belts are cold, the sudden startup of the alternator may result in a squealing, slipping belt. I get a squeal with two new belts. Those with a single belt have noticed rapid wear. The factory used two belts or a serpentine belt with the "3G" 130-amp unit produced for police and ambulance use. This alternator starts working hard at low RPMs and there is a big load on the engine at start-up. For those of us in colder climates, this is more of an issue. (Southern users probably won't care.) A delay would be ideal.

I propose to use this device to delay the alternator power-up (excitation) for half a minute. This way, the belt catches, tightens up, and doesn't create its own load on the starter or the cold engine. Reduced noise, slipping and wear on everything is the benefit.

Link: http://www.wolstentech.com/products/...delayrelay.php
Go down to the bottom for the TDR-P version.

There are two other uses for this device, as a radio/auxiliary circuit delay, and as an EGR warmup delay switch. You might think about getting two. They are inexpensive, and about $29.

While looking for a solution, I ruled out the old mechanical, heated-element type used on Chrysler products as an EGR time delay switch, and then ruled out the Duralast EDS2xxx series as being too expensive. They want about a hundred bucks for those babies. I also couldn't get any electrical or time delay specifications on these more expensive, and less-reliable methods.

Technical Information:
The alternator used is the "3G" 130 amp unit that is such a popular upgrade for the Mustang, Ford performance cars, and our FE-powered trucks. Mine is the top of the line unit listed under 1996 E350 van. ( Few need the high-temperature version, so use the Taurus or other normal part number. )

This time delay switch would be only used on the Light-Green/Red alternator excitation wire, not for Field winding control. This is the same wire that goes through the ALT light bulb, and/or a resistor in parallel.

My information so far is:
(A) inrush surge current of perhaps 3 amps, and then less continuous. (Estimate)
(B) the "12v" feeds may run at 14.8v continuous in cold weather.
(C) startup voltage may drop to 9v.
(D) ideal delay-on timing is thought to be about 20 seconds . (E) the controlled wire is about 20 gauge, and about 5-foot long offering some resistance and minor inductance.
(F) the device should be mounted in a splashproof container, or out of the way of a pressure washer. Anything with terminals can be shorted.
(G) The TDR-P is left unpowered in on OFF state, with a REQUIRED ground connected permanently.
(H) When supplied with battery voltage, to both the 12+ and '1' positive trigger terminals at once, the unit begins timing to the selected number of seconds, and then makes the connection to the 'L' terminal. This is called a "delay on make" connection.

Settings: The TDR-P can be set to behave differently for various uses. It has tiny switch, and adjustment for the time delay. The default settings are just about right. Set the '1' adjustment in about 5 turns to start.

No Worries: No need for additional, or second, trigger event. Just keep key turned on. You shouldn't need any other circuit protection; it already has TVS protection built in. Reverse polarity protection is built in. If you're only running 3 amps through it, it doesn't need to be vented at all. It gets slightly warm at 10A, but with 3A you probably won't even be able to tell. If you turn the key off, it will reset itself.

Wiring:

You can put the TDR-P device anywhere along the Light-Green/Red wire. Just keep it away from high heat and water. Only small currents go through it, so no big deal.

Ground the TDR-P 'G' terminal (Required).

Instead of a single Light-Green/Red wire going from the Ignition Switch to the alternator 'I' terminal, you will cut, and insert the TDR-P into the wire, and have that same wire go to the TDR-P '1' terminal, where it acts as a positive voltage trigger.

The other end of the Light Green/Red wire exits out the 'L” terminal, going on to the alternator 'I' terminal as before.

The '12v' feed wire can just be a jumper from the '1' terminal, or you can feed it separately from a new 12v wire.

The WolstenTec website has all the directions, pictures, and wiring diagrams you need. Since the TDR-P comes in different versions and can be configured differently, it looks like a big deal, but I see that it is really very simple for us.

Technical comments on this PROPOSED solution are welcome.

 

Have you tried this yet?
I'm considering a switch next to my fog light switch to run a small relay, but this might be the cat's meow. LMK what you find out if you try it.

 

Have you tried just putting a simple switch in the exciter wire to see if your theory actually works?

 

I am assuming you all know what is happening and why these 3g swaps have a screeching belt? The 3g alt is swapped in, and then you can say "I have got a 130amp high output alternator", but the belt drive system on the older vehicles can't handle the load when the alternator goes to full output(right after the engine is started).

The 3g does have better output at lower rpms though, so some sort of timer would cover up any issues till the batteries recover from the start-up. But, if there is ever a situation where you really need all the output of the 130amp 3g, a timer is not going to hide that.

 

Franklin2, Yes, the low-RPM capability is exactly why we run these. The heat-resistance, two internal fans, and internal regulator are three other common reasons. I like the very stable DC output for electronics.

But, I do believe we can get some pretty high amps out of the unit, with a double belt. There were double belt 95/100 amp units in ambulances, big Lincolns, and tow trucks. A number of heavy trucks were equipped this way from other manufactures, including higher-amp units (no details, hearsay from truck dealers). There are small case, and large case versions. My large-case probably also has a little start-up enertia also.

Wyowander: Good point. By many reports, putting a switch in the excitation wire will keep it from turning on until much higher RPMs, but since there are many versions of the 3G internal regulator, a blanket statement might not be appropriate. I would like mine to wait for 30 seconds or more, so I don't want to hold a switch that long.

For such a small current, you won't need a relay. A good quality momentary-off switch would work just fine. I haven't identified the exact inrush current, but it appears to be minimal with a long, small wire. I used a 3amp fuse on it with no problems. Marine users do this kind of thing all the time, as they have larger alternator-to-engine-size loadings in some applications.

Comments welcome.

 

Have you tried a "soft start" voltage regulator ?

 

The regulator is integral to the alternator. It is the top-of-the-line version already. I won't be replacing it until I do something stupid to burn it up.

That is a good idea in general. I see that the industrial generators and big trucks have a soft-start feature built into their units as a norm. New cars use computer control even.

With the understanding that this is in addition to a delay mentioned above... I have looked into how they get the slow turn-on. One way is to use an "inrush limiting thermistor". A CL-110 looks good to me, but an electronics guru would have to spec this out for us.

Link: http://www.ge-mcs.com/download/temperature/920_325a.pdf

These components look like a big, flat, ceramic capacitor. Very rugged, they come with ratings up to 8 amps. We just need a little one. The idea is that it has a high resistance when it is cold, and a lower resistance when warm. Then, when power is applied, the resistance goes down to almost nothing. You can think of it as melting with voltage.

Just more ideas. Call me crazy.

 

Most 3 g reg's are gray (OEM). There are some out there for Taurus or Crown Vic police that are black and white. They already have soft start engineered into them and physically fit any 3 g and have same plug. If you want one, let me know.

I have a funny feeling that electronic tweeking may not solve the problem. I strongly suggest an easy test: Unplug the regulator, see if the squeel stops.

Another approach to get rid of the "squeeler" would involve going to a multi groove pulley, which opens the door to clutch damper and decoupler engineering. These pulleys are readily available for $75 or so.

Also, an over size v belt pulley,available at your local speed shop,will give the belt more surface area to grip and less chance to slip. You'll lose some amps at idle but as long as you have normal loads/usage you'll probably not notice an electrical difference.

 

You guys need to get me up to speed on this, I think I am missing something. I am not up on everything that is out there.

My first reaction was, if the alternator goes to full output for any reason, the mechanical drive system should be able to handle it.

But now I am hearing there are some control systems that actually do have a delay on start-up. I would think it would be normal for the alternator output to go high right after starting the engine, but are you sure these delay systems are to keep the belt from squealing? I am also not sure of the purpose of putting such a high output alternator on a vehicle where the belt would squeal, unless there is some study that has found that the belt will not squeal after it has run for a awhile or some other circumstance that will prevent it from squealing during normal operation, but will make it squeal right after start-up.

 

A 3g alternator takes about a 7hp electric motor to drive it at full output.
So I'm guessing if you crank on the loads, your engine loses about 7 hp, particularly at lower RPM's

The "soft start" was designed to deal with this problem: You're sitting at a light, and suddenly your AC unit or rear defog kicks on. For 4 cylinder lower horsepower engines, the alternator actually slowed the engine idle speed enough to cause a "stumble". I think this was first brought to the table by Honda in the late 90's Civic when they were known to almost stall out.

The soft start causes the load to be applied gradually on a 3-5 (approx) second curve, so the computer has time to compensate. Also the driver would not notice a sudden drop in idle speed, which is the main reason(we're thinking) that Ford used it on the Taurus.

 

That makes sense, thanks for that explanation.

Would we agree the original poster's timer is going to just delay the alternator coming online till the battery self recovers a little bit and the load presented to alternator is lower? Would that be a fair assumption?

 

First we gotta get 3/4 1972 to say if the slippage stops when the alt is disabled by unplugged v. reg.. If it does, the other thing that still bothers me, is that generally, if the starting system is operating sufficiently,the alt output doesn't increase dramatically. Usually it only increases 20-30 %. That's not as much as AC or several other loads that the average user might have.

I think you hit the nail on the head earlier when you said the problem is that the 3g was not designed to operate with a v belt system. A voltage reg with LDR (load delay response) may correct this because it gradually applies the load. BUT, everywhere FoMoCo uses this alternator, it's equipped with a serpentine belt and a tensioner. The rotor weighs a good couple pounds more than the rotor out of 2g or 1g.

This is one of those deals where the "proof's in the pudding". And what works for some people, may not work for everybody.

 

Gents, you are on-track with your comments. To confirm:

Yes, the slippage does not occur with a warm re-start, because the battery is fully charged. Yes, causing the alternator to not charge stops the slippage, even at cold start-up. A belt doesn't slip when it gets up to speed, even when it is loose, as most of us have experienced (cringe). I'm guessing that is due to heating and centripatal tightening action. Yes, the armature weighs more, and that is extra inertia, but it doesn't cause the belt to slip by itself, in my case anyway. Yes, the 3G alternators were quickly switched to serpentine belts for a variety of reasons.

There were a number of small and large-case 3G alternators from about 95 to 180 amps. If I recall, there were something like 9 different designs (not just different clocking). Many users are putting the small-case version to work, and it doesn't begin putting out until a significantly higher RPM.

This is interesting that some of the integral regulators may have better soft-start capability than others. I haven't found anything on that yet. Post links if you see something of value. White, Gray, Black....? (Mine is the gray one)

I'm attempting to optimize this with the existing stock double-V-belt configuration that came on my camper special, and the extra-cooling option. Like I said, the serpentine belt set-up would be nice, but it appears to be a huge cost. Aftermarket prices are over $800. If anyone knows of parts that can be adapted to the FE 360/390, do post (in a separate thread). The 3G alternator comes with a suitable serpentine pulley, so it is the crank pulley, and waterpump items that are the issue. (A/C?) A v-belt groove for the P/S is required.

Total amps at higher RPMs are not usually the main goal, so some users might find a bigger pulley a good option. A larger pulley on the alternator would diminish the low-RPM performance, and that is why I'm using the 130 Amp 3G in the first place. I found four different sizes of double-V-Belt alternator pulleys. Two stock, and two racing aftermarket.

I appreciate the brainstorming.

 

Ok then. If the slip stops for alt unplugged, the LDR v reg should help, but that would still be experimental. The longest, slowest, curve is what you're after. If you want me to find you one, I can. They probably cost around $20. rebuilderinabox@gmail.com.

I think your original idea will work also, but it sounds expensive, and it seems like it would apply loads suddenly, where the 3-5 second curve and a bolt on fix, might be the way to go.

 

I just came across this thread after tons of searching online, read it, went outside and unplugged my alternator (an upgraded capacity one on a super-tight brand new premium V belt that ALWAYS squealed upon startup) and my van started up silent as a whisper, not even a tiny chirp.

I upgraded my alternator to the higher capacity one to AVOID problems, not create them. THANK YOU SO MUCH for this thread, I think what I'm going to try to do is put a toggle switch to interrupt the alternator on/off draw so I can start it quietly and engage the alternator once I'm out on the highway.

If anyone ends up with a working/proven solution to this, please be sure to post it.