dat620_73

The main problem with rockauto is/and has happened to me, if they send you a wrong part or a defective part, you pay the shipping to return it. Doesn't matter who's fault it is.

Thanks guys, I was hoping to be el cheapo and just need a valve. AutoZones website says not available. I don't have that much confidence in rockauto getting me the right part (been down that road too many times). Anyway I'll find on tomorrow. Thanks again!!

Ok so I'm pretty sure of what I need, just basically looking for confirmation. I was driving my '73 620 with an all stock braking system today, everything was great, it stopped like normal, until later in my commute when I noticed the pedal was stiffer than usual. So I turned down the radio, pressed the pedal and you guessed it a pshhhh sound from under the dash and a stumble in the rpm. All which leads me to believe the power brake booster. I then second guessed myself, maybe the check valve. I figured if it was a valve i'd loose vacuum all the time not when the pedal is pressed. Right? Also any ideas on where to get a booster?

Key word "simple". I'm sure you have posted a how to. So I'll look into it. I did just plug in my old regulator and went to go turn on loads starting with headlights then wipers, as soon as i turned on wipers the dash lights started flickering and the truck died.put new regulator back in Went to restart it, and nothing no click no power to anything ( like the batt is disconnected) checked fuses ok, disconnected the battery and reconnected still nothing. Unplugged and replugged the lead going to the starter solenoid (cause why not) and the lights came back on. Old reg is now in the trash pheww.

The problem with the internally regulated alt. Is i don't have the room. My alt fan is 3/8" away from the lower rad hose. Previous owner "upgraded" the radiator.

The voltage regulator is external. I replaced the original one about 5-6 months ago. It was from what I can remember allowing over 15v back to the battery. I tried plugging the old one back it at the beginning of this whole mess, to see if that was the problem. It changed nothing, however two wires came out of the socket on the regulator side so I had it replaced under warranty last night when I had the alts tested.

Auburn isn't that far from me, I'm in Modesto. I have the one I pulled out, I'm not going to spend $20 shipping for a $7 core charge. I go to Reno about once a month may I'll drop it off. Thanks.

Sounds good I'll order that today, you were on the right track as well. I'll drive it this week and see what happens. Thanks guys.

Yeah I was excited to get the light off, but still going to be in the same boat. Larger alt? Smaller pulley? Carry a solar panel in the bed to help charge the battery. Just kidding about the solar panels (kinda) any ideas of where to start chasing wires?

All Loads on: @800rpm 11.9. @2000rpm 12.2 I misread the meter not 12.9 it was 11.9. No loads: @800rpm 13.6. @2000rpm 14.3

So that was the problem, my dumb ass assumed that spade connector was a ground. I grounded the chassis of the alt and the light went out, and the alt started charging at 14.3v and 12.9 with all loads on. Thanks Crashd420 and banzai510 for the help. I love this forum, you guys are the best!!

Thanks for your help with this. Yes all 3 lights are on with key on, then I start the truck and the alt/charge light stays on the other 2 go out. There didn't seam to be threads in the hole for the ground eyelet that's why I put on a spade connector.

Ok so I bought a remand alt from rockauto, it's a Mitsubishi, and the one I took out was a Hitachi. The tag on the new alt said it was interchangeable. I did have to modify the ground from an eyelet to a spade. Now when I start the truck my charge light comes on. I checked voltage at the back of the alt and it's 11.3. If I rev it up it gets to 12.4 and the light stays on. Good thing my tach no longer jumps around. I went to O'Reillys with both alts. My old one failed, and the new one passed, at 14.5. the pulley diameter looks the same on both, the belt is as tight as I can get it. I don't know where to go from here

Thanks for reading my novel! I replaced the battery cables when I replaced the battery. I'll try the test light thing. I'll have to make one though I threw mine away when I got the power probe. The belt is tight almost too tight in my opinion, the previous owner "upgraded" the radiator and the lower hose runs dangerously close to the alternator fan. I was going to get a smaller belt if I pull the trigger on the alternator. Update. Did the test light draw test. It will for 1 second barely light up a regular 194 then go out. but it will light a 194 led. I know led needs very little voltage.

Ok, here's the situation, I've been using my 73 620 as my daily since my last post. In the last month I've noticed on Mondays (after sitting all weekend) I need to jump the truck to get it started, and don't need to jump it again until the next Monday. I work nights Mon-Fri and figured since I only drive 9 miles round trip a day the battery doesn't get an opportunity to completely recover from the use of lights, radio, amp blah blah blah while driving. So Saturday I only drove the Datsun, about 25 miles running errands. Monday I go to start it, dead. So I check for parasitic draw .07 milliamps (clock/ memory on the radio I figure.) So I connect my power probe and here's were it gets weird. No loads idling at 1000 rpm I get 14.5v, turn on all loads (headlights, blower motor, wipers, radio, hazards, brake lights) voltage recovers to 14.5v, if I rev up to 2000 rpm with loads on voltage drops to 11.8v. WTF!! I have replaced the ballery, and regulator with in the last 6 months. Side note the tach needle is jumpy as well now. I'm figuring it's the alt. but is there something else I'm not seeing?