project7s

iTrader: (5)

my car is a 1980, i was driving it down the road and it was doing fine when all of the sudden the idiot lights in the dash came on like the belt had broke so i pulled over checked it but it was fine. as i start the car again i notice the tach is still working as the volt gauge while its running plus the idiot lights are still on. ive searched and checked the fuses but no luck. thank you for any help

NCross

iTrader: (18)

The alternator or regulator is bad. Check voltage at the battery. It should read close to 13.5-14.00 volts.

project7s

iTrader: (5)

the alt is brand new like two weeks old. im sure its possible though I just got a bad one but could there be something wrong that's killing it? I will take it up to the autozone and have it tested in the mean time thanks.

NCross

iTrader: (18)

External regulator. Check the regulator. Located near the brake/clutch cylinders. Check the FSM for the exact location.

DivinDriver

iTrader: (15)

80's have internal voltage regulators built into the alt, just like FB's - external v.reg ended in 79.

Could be a couple things; My starting point would be at the choke-and-check relay or the connector/wiring for it, but the alt could be new-but-bad.

Check your alt connections, too.

project7s

iTrader: (5)

you are correct the regulator is in the alt. so I took it in and they said that both the reg and the alt were bad. so I got another one and put it on the car and tested it and its show the regulator is bad. at idle it has about 12.7 volts. I also checked to see if there was a drain on the battery and there is not one.
dd what is the choke-and-check relay ive never heard of that?

jtthebiggafigga

Pull the alternator and have them bench test it. If it fails and they give you a new one have them test it before you take it home. Rebuilt doesn't mean anything anymore, just prettied up sometimes.

NCross

iTrader: (18)

Thats good to know for me then. I planned on a s5 alternator upgrade and internally regulated ones are easier to swap. Now that you mention it I dont see the regulator in my bay!

I used to work at Advance Auto Parts and every once in awhile we would get a part in that looked like a core! We always opened the box and check before we gave it to the customer to be sure it was the real part.

project7s

iTrader: (5)

yeah that's what I plan on doing with this next one, so far ive tried the two they had in stock and the third had to be ordered.
ok so I found the choke and check relay but according to my wiring diagram it goes from the alt to the relay then to the choke which im assuming is the one under the dash because all of the emissions has been removed and its running a racing beat holley set up so it doesn't have the choke on the carb any more. i maybe missing something but how could that cause the regulator on the alt to go out? thanks

DivinDriver

iTrader: (15)

Left side of the engine bay, on the fender, there's a group of a about a half-dozen relays that share a common mounting bracket. One is stamped "Choke & Check Relay" on top (if it hasn't corroded away). Right next to the Air-Conditioning relay (if you have one).

Works in conjunction with the choke automagnet, but it also connects the Alt to the idiot lights; Provides the "light them up for checkout" ground to the warning lights & tach voltmeter function when the ignition is on & no/low voltage is present at the "L" connector on the alt.

Essentially, it's the gizmo that lights all the idiot lights when the key is on but the engine's not running.

If the relay is bad (failed closed) (or if the "L" output of the alt is bad), it throws all the idiot lights and the tach into pre-start mode.

There's a diode in it that can fail, too.

project7s

iTrader: (5)

oh ok, i did find it on the car and took it off just to clean where its screwed on just to make sure it was getting a good contact. since when i put the second bad alt. on that had just a bad regulator the dash lights went out when it was running and the tach went back to working as a tach so im assuming that it must still be good. so assuming that and i cant think of any thing else would you just think that ive possible just ran into a bad batch of alt. from the store? ive ordered one from another store as well now just because ive lost faith in the autozone's parts lol. seems if it were something else with the car when i started it either i would have a blown fuse, see smoke from a wire shorting out, see sharks, or here something i would think.

rotornoob

iTrader: (2)

^ " See sharks" lol

DivinDriver

iTrader: (15)

If replacing the alt made the symptoms go away, then you have solved your problem.

There's no reasonably-likely electrical failure that could be causing the alt to go bad without some other symptom showing up (blown fuse, smoke, things not working, etc) - it's a very simple electrical system in these cars.

project7s

iTrader: (5)

ok so I put the other one that came in today on the car and so far it seems ok, but the most it will charge up to is 13.50 volts and that's with nothing on lights ect. just the car running. with the lights on it drops down to 13.00. is that normal for the sa's? my 85 gs is at 14.50 at idle with nothing on it just seems odd to me.
also I notice that for some reason when you turn the turn signal on the tach will quiver and jump up a bit could that be related some how?

rotornoob

iTrader: (2)

^ did you do a stock replacement? The stock alt has a relatively low output and many first gen show this "bump/dip" when turn signals are activated. An easy fix for this is to upgrade to an s4 alt. I've also heard that checking your main body ground (strut tower) and cleaning it up helps. Also try grounding the engine too...that also seems to reduce this issue. A quick search should turn up a few hits. I know I saw a thread about this not even a month ago

project7s

iTrader: (5)

ive cleaned all of the connections to make sure they will get a good contact. I have thought about running a ground wire from the battery over to the engine.
dd last night i was working on the car and now only sometimes the when you turn the switch to the "on" position the volt/tach gauge never moves and only the check coolant light starts to come but not all the way and fades away. does this sound like that check relay might be going bad but not completely yet? also by a multi-meter on the battery its only at 12.50 volts at idle now. thank you for all the help. this thing is being a real pain.

NCross

iTrader: (18)

Is you RB pulley under drive?

NCross

iTrader: (18)

Aluminum Alternator Pulley -Double Sheave 74-92 Rotary Engines (All)

***The Racing Beat-designed Double Sheave Aluminum Alternator Pulley reduces alternator RPM approximately 20% from stock RPM***



, and is intended for high performance and moderate race use. It is compatible with either the stock main pulley, or assuming you are not using the air pump, our Double Sheave Aluminum Main Drive Pulley. For use on virtually all 1974-92 12A and 13B rotary engines. The weight of this pulley is 7.2 oz.

Precision-machined from billet aluminum alloy, each pulley is finished with a hard anodized surface treatment to ensure superior longevity and excellent abrasion resistance. As compared with standard anodizing processes (typically identified by components finished with a bright red or blue finish), a hard-anodized aluminum component will offer comparatively superior durability and wear characteristics. Hard anodized components are typically identified by a darker surface coating, most commonly with a dark grey or black matte finish appearance.

Note: It is not practical to offer a standard replacement belt due to the variations in engine configurations. After measuring the distance required for your application, we suggest you contact your local auto parts store to obtain the required 3/8-inch wide replacement belt.

project7s

iTrader: (5)

the alt. pulley is the stock one that came on the alt from the parts store. this is not the car in my sig that was a car that i sold a while back.

NCross

iTrader: (18)

All I can tell you then is to return it and get an s5 alternator. A bit pricier but almost double the output. Mine sits at about 13.0 volts with accessories on at a 750 RPM idle. rev it to 1200 RPM or so and it sits at about 13.6 volts. 8 years old reman with dual belt pulley.

DivinDriver

iTrader: (15)

The C/C Relay usually is either all good or all bad. I've never seen one go 'kinda bad,' though I suppose if the contacts inside got badly pitted up you could lose some voltage in it. Doesn't sound like a match to your symptoms.

The relay schematic is in the wiring diagrams; you can check it with an ohmmeter if you have one.

project7s

iTrader: (5)

ok so upon driving the car down the maybe two miles I started smelling some thing burning like a short so I pulled over. I didn't see any smoke but when I opened the hood I could tell the smell was coming from the alt. after pushing the car home I took it off and had it tested sure enough the regulator in it and the alt were bad. after I got another new one, before I put it on the car I checked every wire going to the alt. and I found the white wire with the red stripe and the black wire with white stripe going to the ignition switch under the steering column right before the plug in, both of them had a bare spot on them like someone had tapped into them at one point, and were apparently touching every now and then. they had put the tape back around it but after really looking at it you could tell it had been untapped and put back. so I taped them separately like they should have, put the new alt. on and so far its charging good, the idiot lights come on with the switch in the on the position, and the tach isn't quivering when the lights are on and you turn on the turn signals. im just hoping that that was the problem and the car will be dependable now.

DivinDriver

iTrader: (15)

That could be a bad thing. Tape both up individually and soundly with proper electrical tape, and check around under the dash for other PO-induced silliness.