Charging system failure.

Hello all,

I have a 1980 Toyota truck that was just acquired. It does not charge. The previous owner just put a new alternator and a new regulator into it. They don't even have dust on them. But there is no charging AT ALL.

The alternator has the big output stud sticking out the back and then a three wire connector.

I briefly connected 12V to each of the three connections on the back of the alternator. One of them causes the alternator to put out BIG TIME. So I believe the alternator is okay.

This leaves the wiring between the alternator and the regulator. The three wires from the regulator go up to a plug. They have continuity from the alternator end to regulator end plug. At the regulator plug one wire doesn't go thru because the regulator side doesn't have a matching wire.

At this point I opened the regulator but there is no figuring out what is happening under all that potting compound.

So I got a new regulator and plugged it in. No joy! Still not charging.

If I jumper from the HOT wire at the regulator connector to the little green wire(regulator unplugged) then the alternator again puts out maximum.

At this same connector one wire is always hot.

One is switched hot.

While the regulator is hooked up and the engine is running one wire is also at 11V.

One is at 10V.

The charge idiot light has never been seen and if I connect every wire in the harness to ground thru a 12V bulb the idiot light still doesn't come on. Should it?

Can the idiot light being burned out cause the alternator to cease output?

What are the three connections on the alternator? I can relate to a Delco alternator with the HOT stud and a field connector and the R connector for the idiot light but I can't figure out why the Toyota needs 3 wires plus the hot stud.

I purchased the Chiltons but all it has is a schematic showing:
Hot
Switched hot
Idiot light
and three "other wires between the regulator and the alternator but not what they do!!

With the regulator hooked up and engine running I never measure any voltage on that one wire that forces full alternator output.

Any suggestions?

Thanks Denny.

I will shoot it up tomorrow morning and post pics here.

Here are shots of the system.

er...once I remember out how to post a picture!.. Grrr!

Oh yeah the reply page!!

http://tinypic.com/i3xhs0.jpg
http://tinypic.com/i3xhzd.jpg
http://tinypic.com/i3xi5v.jpg
http://tinypic.com/i3xid5.jpg
http://tinypic.com/i3xiio.jpg
http://tinypic.com/i3xil3.jpg
http://tinypic.com/i3xiqs.jpg
http://tinypic.com/i3xish.jpg
http://tinypic.com/i3xiu0.jpg
http://tinypic.com/i3xixz.jpg

Other mentions..

That little harness is for what?!?!? It doesn't transpose any connections the existing original cable plugs into the alternator just fine. ...

Using it or not using it makes no difference in my results.

Why would the original charging system be completely replaced with no functional improvement? Speaks to wiring problems.

Note the frayed bare black wire on the vehicle harness. odd...
Disturbing... I removed a couple of inches of tape that stopped right at the bared wire.

Man all Jap charging systems are fused, first thing ya need to do is go to the fuse panel and check the fuses, You wouldn't be the first guy to rack his brain on one of these just cuzz the fuse was blown......

Can't be the fuse because the same fuse that runs the ignition and umpteen other things is the fuse to the regulator.

We jumped from the hot stud on the alternator to the plus battery terminal directly, which by passes the fusible link too. With no suck sess.

I just spent an hour at the library looking at the schematics. They all show the regulator with all these labeled connections F,E,B,etc,ect but of course both of the new regulators just have some frikken wires sprouting out of them into a flying connector with no labels. And of course none of the wire colors on either regulator have anything common with the schematic colors!!! ARGH!!

If the light isn't coming on ever, I would change it. The idiot light has to be working because this is what 'primes' the alternator to begin charging. When the ignition is turned on voltage flows through the light, through the regulator to the field wire on the alternator.

Quote:

---

Originally posted by califgrrrl
If the light isn't coming on ever, I would change it. The idiot light has to be working because this is what 'primes' the alternator to begin charging. When the ignition is turned on voltage flows through the light, through the regulator to the field wire on the alternator.

---

Purty smart for a gurl (lol)

Man my stuff only goes back to 1983,but looking at that it says fuse #12..15 amp is for charging system & emission control, also looking in the locator there is a charge lamp relay located in the right kick panel
looks like 3 wires go to it a white/black wich goes to ground,,a yellow, and a yellow/white.....hope this helps.

Quote:

---

Originally posted by HWORRELL
Purty smart for a gurl (lol)

---

Duuuuh, well thank yew...:p

Yew ain't so bad yerse'f mistur H. ;)

Seriously, that relay would be a good thing to check also. Seems like he's ruled out almost everything except that circuit.

HWORRELL; I re-checked that fuse situation.. You are correct I was mistaken, there is a fuse that runs only the alternator and a fuel solenoid and sumptin else like carb heat. It was an incorrect 10A fuse even tho all the books and the fuse cover say 15A . It wasn't blown and I replaced it with a 15A. But it still made no difference.

We rechecked the all the signals with respect to the harness plug from the dash and all the signals "seem okay" with the exception of the charge lamp???

We stripped down the wire housings down to the alternator from the regulator plug, so we could actually lay eyes on the wires and they all look okay.

califgrrrl; Is that charge light some strange voltage like 2.763734453V bulb or is it a 12V bulb? Is there a way to test it without pulling the dash apart, groan....?

Hmmm charge lamp relay?? Steewpid! Just give me a Delco with an internal regulator.. :(

I will look again at my schematic to see if there is a charge light relay in this model year. Thanks.

It's possible that the light could be less than 12v, that may be why there is a relay. There should be 12v going to the field wire with the key on.

AH HA! That is some info I was after. I wasn't sure when the field should be energized with the key or with the alternator spinning.

We get goose eggs going to the field wire outta the regulator which is of course the tragic result of The Problem. I will be checking that light/relay situation as soon as I get back to my shop.

In answer to your other question, why are there three wires coming out of the Toyota alternator connector? Two of the wires (one is field out, one is stator out) on the Toyota alternator are on the inside of your internally regulated Delco alternator.

Wait a minute...

There are four (4) (IV) wires coming out of this alternator!

The big stud => Stator?
A green wire => Which is the field (fer sure)
A Blue wire => ??
A Black wire => ??


Care to comment on the ??s?

Okay there does appear to be NO charge light relay in this vehicle only a choke heater relay.

YES! the charge light was burnt out!
It's one of those twist into the circuit board lamps. I pulled it and the brake bulb next to it. They are both the same bulbs.

I exchanged the brake bulb for the burnt out charge bulb and..... no difference.

I got to wondering about the wiring back to the bulb. The bulb has 12V applied to it when the ignition is turned on. So with regulator removed I grounded the yel/white wire that goes from the regulator to the charge lamp thru another 12V bulb. They both came on about 1/4 brite, about what I would expect. For the bulb to light normally the regulator has to bring that wire down from 12V some, to get a voltage difference across that bulb and make it glow.

With the key on and the regulator hooked up I get 12V on that wire at the regulator which means the regulator is acting like it is open on that wire.

Time to investigate. I opened up the regulator dug it out of the silicon goo. There is a big power resistor laying on top. It measured 18.6 Ohms. The label sez 10% 19 Ohms which means it is fine.
There is a big diode that connects to that resistor (series) it tests fine too.

I pulled the little hatch from on top of the thick film circuitry board inside.

There is a thick film board with 2 Integrated circuits directly bonded to it.

There was a large blob of solder sitting on the clear silicon gel pool that the thick film board is under. I removed it with tweezers thinking, "this must be it!" Then I inspected the entire thick film board and ICs with a high power microscope. I could see no sign of any toasted little traces or IC traces or component failures. The big solder blob didn't look like it had penetrated the gel...

I reassembled everything plugged it in and..... the charge light doesn't come on with the key, and the alternator doesn't charge... :CRY:

The ???
Big stud: stator out to batt
Green wire: field in from reg
One of the black or blue is the field out, I'm not sure which. It should come on with the key. (I would guess its the black)
The other comes from the stator, this tells the regulator what's generating so it knows whether to turn off/on the field. This one won't put out till the alt is turning.

Disconnect the plug at the regulator, turn the ignition on then ground that Yel/wht wire coming from the bulb, does it light then? If so, then you know that circuit is OK. What the regulator should be doing is taking that 12v, running it through the field (green)and back to the regulator to ground. (blue or black) If you're not getting a good ground this can't happen. Then check your block and body grounds. Physically remove them and make sure you've got clean metal to metal contact.

Why not stick in the delco and eliminate all that other stuff?

I worked for toyota for 15 yrs ,I always had a hell of a time with the old alts on pre 84 trucks ,once I had one that I messed with for days and found that toyota has 2 alts about the same ,take a real close look at the 3 wire connector on the alt is it exactly the same ,the one I had was a little different it would plug in but it was hard to do just something I ran into ,also I have had a lot of crappy aftermarket regulators

Quote:

---

Originally posted by califgrrrl
If the light isn't coming on ever, I would change it. The idiot light has to be working because this is what 'primes' the alternator to begin charging. When the ignition is turned on voltage flows through the light, through the regulator to the field wire on the alternator.

---

wow that what i was thinking. califgrrl you are so cool
on some of alternator your can jump the two wires with a resistor or a delco one wire alt the older mopar alt work good to with the one wire regulator

Quote:

---

Originally posted by califgrrrl

The ???
Big stud: stator out to batt
Green wire: field in from reg
One of the black or blue is the field out, I'm not sure which. It should come on with the key. (I would guess its the black)
The other comes from the stator, this tells the regulator what's generating so it knows whether to turn off/on the field. This one won't put out till the alt is turning.

Disconnect the plug at the regulator, turn the ignition on then ground that Yel/wht wire coming from the bulb, does it light then? If so, then you know that circuit is OK. What the regulator should be doing is taking that 12v, running it through the field (green)and back to the regulator to ground. (blue or black) If you're not getting a good ground this can't happen. Then check your block and body grounds. Physically remove them and make sure you've got clean metal to metal contact.

---

O.K. Caligrrrl, your a little too smart for the average home mech. and specially for a gurl,whats the story,very rare breed indeed......

Something Caligrrl hit on,I just looked at the 1983 diagram and that black wire runs from the regulator to the alternator and has to be grounded ,check and make sure it is grounded,seems to me it should ground at the lower alternator mounting bolt,but in any case it positively hasta make ground........

The Black wire is indeed grounded on the alternator. It is one of the little scrawny "three wires in the connector" The actual return current is left to the alternator mount and frame bonding which was inspected and found to be good, if not lamely designed. They ground the negative of the battery to the fender then bond the lower part of the fender to the suspension and the suspension to the engine block... Lame or what? The battery ground should ALWAYS be grounded with a stout Starter Current sized cable and the chassis and suspension (?) grounded from the block or directly from the battery too.


Boy you would think that black ringed stud would be negative if the red ringed one is positive BUT! in this case it is ALSO positive!

There is another big stud down lower that has a condenser body screwed to it and the positive condenser lead goes to the indicated black ringed stud.

Okay here is where we are now.

After hours at Google and at the car parts online stores I have discovered something not EVER mentioned in the Toyota manuals...

The Toyota nitwits put both A-Type and B-Type alternators into those Toyotas.

To refresh you.. The A-Type alternators, like ALL Delcos, have the field internally connected to the DC+ output. To control the alternator's output the regulator grounds the Field terminal varying amounts... More grounded more output. This is why on Delcos you can stick a paperclip into that little D slot and force the alternator to full output. (by essentially shorting the field terminal to the case)

B-Type alternators have the field wire GROUNDED inside the alternator and hence the regulator feeds more VOLTAGE to the field terminal to produce more output.

Obviously I have B-Type alternator because if I feed 12V to the field terminal I get maximum output.

Now if you've been following this thread you will know that my regulator seems to have all the correct signals going into to it but obstinately continues to send a big ZERO out to the field terminal!

My regulator is an A-Type regulator!!!

I figured this out because if you go to say..., Kragen Auto parts on the web and hunt down Alternators and Regulators for this Toyota you see umpteen references to 5-Wire and 6-Wire regulators. You also see reference to "B" type alternators.

Further searching finally turned up an application note at a car parts store that explained; Beware there are two types of alternators and regulators used in Toyotas. The alternator type must match the regulator type!!

If the wiring harness has six pins in the regulator connector then the vehicle was made as a B-Type. If the harness plug has five pins then the vehicle is an A-Type. [note: the plugs accept either they just depopulate one pin {the jerks}]

Well my harness has six pins... B-Type.
My alternator, via my test demonstrated it is a B-Type.
My regulator has five pins... A-Type.

This is why I'm getting nada...

How did this come about? Remember I just acquired this vehicle from someone who had replaced the alternator and regulator. {I never had a chance....}

Furthermore... If you go to the store and get the typical car-parts-jockey and he puts in your year Toyota he gets 15 alternators on his screen they are listed in order of cost, cheapest first. The B-Alternators are the cheapest. He-goes-to-the-refrigerator-and-gets-the-box... and hands you the B-Type alternator. Then when he looks up the regulator THE A-Type REGULATORS ARE THE CHEAPEST AND THEY COME UP AT THE TOP OF THE LIST. Again he assumes you want the cheapest... and hands you the A-type regulator... The die is cast..... This is what happened to me when I first discovered I must have a regulator problem, I went to the local Kragen's and asked for a regulator for that vehicle. I was handed one. No mention that there might be different types or that different types are available, "do you have a preference mister?"

Turns out I was summarily handed the cheapest one on the list an A-Type.

So anyway this is where I'm at. Later today I will exchange the Wrong Regulator with a Correct Regulator and see what happens.

I will report back!

Quote:

---

Originally posted by DennyW
:) yep.
HWORRELL , can you post or send me a copy of the wiring ? I can mark it up for him.

---

Sorry Denny wasn't ignoring ya,had just popped into the shop to do some bookwork when I was posting earlier and left before your request,just now took a break from the coupe and am on the kids puter,sounds like he's got it figured out now anyway. Ya know I started to ask him if he had the right alt.last night because on the wire diagram it showed 1 with internal reg.,1 with mechanical reg. and 1 with electronic reg.....

Well we are stalled Ladies and Gentlemen..

Soonest I can have a 6pin B-Type regulator is Monday 10AM. So we wait... :CRY:

Waiting is over... :)

Went in to the parts shop after being called and told the regulator was in... Got there and was handed another 5 pin regulator..The idiots!

So after much grumbling they looked up their local stock and found a '79" six pin in stock!

Well it worked perfectly. So that confirms the wrong regulator in the first place theory. Sheesh.

Thanks for all the help people and giving me ideas to check out.



Now on to the leaky exhaust manifold. I have never seen an exhaust manifold with no gaskets before.... Toyota R20...

don't know about Toyota, but i never use exhaust gaskets on SBC stock manifolds. works better with no gaskets for me.

Hey, you did allright. We all did our best to confuse you, and you managed to fix it anyway!!! :LOL:

Reporting in....
I went to clean the manifold with a big flat draw file. After a few hundred passes it became clear that at that rate it would take another hundred thousand passes to even get close to, barely starting, to even vaguely start cleaning the sooty blow out leaky zone.

I took the manifold to my buddies and slapped it on a big vertical belt sander. Big enough to put the whole manifold on at one time. After 24 minutes of sanding I finally had the soot zone level with the rest of the manifold. I bet that manifold had 60mil of warp on it!!! Disgraceful!

Stuck it on with gaskets. Two. One for each side of the inner "stove" which I had no way to flatten. Torqued it to 30ftLbs

Started it up. Ran it up till it was smokin hot. Then let it cool. Re torqued it the next day. ALL THE BOLTS TURNED ANOTHER 1/3 of a turn.

Reassembled everything and started it up. Without the horrendous exhaust leak I can now hear the failing water pump bearings.......

LOL, :LOL:

Bet you can't wait to drive it and hear all the rest of the noises!

Hahaha.. C.G. How did you know?!?!

The front right wheel sounds like there is a lug nut in the hub cap.. But there isn't! Disk brakes. What can make that noise? Anybody wanna hazard a guess?

you need anti rattlers on the calipers. when it start doing it put, your foot on the brake paddle and see if it goes away **)