I was running a trail yesterday when the "Charge" light lit up on my truck. I spent most of today trying to find the problem. Its not the alternator because that is a fresh rebuilt unit. Of course the online FSM is for an 85, which has the internal regulator, where I have the external. I can't even seem to find the right spot to check the output voltage on the alternator. And what is the little capacitor dealie on the alternator do anyway? Anyone have a link to an 84 FSM online, or have any suggestions what to check next? Details:

1984 22r (carb)
-good ground at alternator
-all wires from alt to regulator are good
-no blown fuses
-the Voltage meter on the dash has been reading at the top of the travel since I bought the truck (2 months ago)
-E-brake light is also lit

Any help much appreciated

RallyRoach

 

dumb question but how sure are you that reman alt is any good?

 

not sure bout the charge light, but the ebrake light is on b/c you are low on brake fluid. Check the level, if its low thats problem

 

could be ,but when both lights come on it usaly indicates a charging problem.

 

Get a volt meter and check the battery voltage before you crank it then after while running. Before any where from 11.5 to 13 volts. After starting should be about 14.5. If not then bad alten or related part controlling charging.

 

you canb also pull the neg terminal from the battery ,if it dies......

 

Thanks for the replies. The reman alt. should be good, as it was bought on Sunday I checked the voltage at the batt, and I'm getting 11.7V off, starting and running, so I'm definitely not getting a charge. I've got a new regulator on order, but its a few days out. I'm at a loss as to what else to check until then. Is there anything under the dash connected to the charging system that could be bad?

thx

RallyRoach

 

still it could be junk, I've gotten a few bad ones right out of the parts house. now i make them test it before it goes home.

 

yeap bad out the box seen it...........

 

i converted my 84 with the external regulator to the internal regulator type in the newer trucks. to bypass the original regulator i had to splice the harness in to the late model plug.(because my harnes was chewed up) the alternator would charge just fine but if the white wire came loose the charge light would come on but it was still charging.

 

I've had 4 (reman) alternators in 6 months. One lasted 4 months, one lasted 2 weeks, one lasted 5 minutes. Current one seems to be holding. All of them came from NAPA, with a lifetime warranty.

 

Guess I'm off to tear the Alt out and get it tested then I really was hoping to avoid doing that....

 

I got the truck working tonite. Just a note to other owners of external regulator alt. Toys: Buy a new regulator first, then a new Alternator if in doubt. I installed the new regulator tonite, bang, no problems. So my old Alt might have been good. I'm not overly concerned, as both were cheap to replace. Thanks for the help!

RallyRoach

 

The 1984 uses actually 3 different charging systems, no components from either system is interchangeable. First, the most common, also known as the cold weather package is the remote IC type. Then there is the remote mechaincal, non california and last, the remote mechanical, for california. The remote IC will have the terminals on the back of the alternator listed as "E,L and F" for earth light and feild. Now this feild is grounded , not powered up, its known as a "A" circuit, while the power type is known as a "B" circuit. And the "L" terminal comes from the diode trio which is basically a half wave rectifier used only to supply feild current and produce a counter voltage to cancel the light. The remote mechanical, non cally and the remote IC system regulators have identical plugs (will connect) but are not compatible at all. Which system do you have? Easy, look at the regulator plug, this is the vehicle harness, not the regulator harness, if its white and has 5 pins, but is a 6 pin connector, its the remote IC type, if the plug is green and is a 6 pin connector and uses all 6 pins, its a remote mechanical non cally. The cally type will be a rounded 6 pin connector, green in color and uses all 6 pins. These are kinda rare. All remote mechaincal type alternators pins will be EFN for earth feild and neutral.