Crashtd420 Posted July 12, 2017 Report Share Posted July 12, 2017 Personnaly I think he lost power on either the white or the white/blue and he's just not turning the alternator or regulator on... what I describe kind of assumes that the alternator and regulator are in working order, and he should be able verify that those wires have 12v when they should.... Quote Link to comment
ka620' Posted July 13, 2017 Author Report Share Posted July 13, 2017 Thanks guys. Alternator passed test twice and i replaced regulator. So im assuming they are both in working order. So im seeing the same voktage as you except for the red/white going to cluster is only showing 2.4 volts. And the yellow wire coming from alt shows no continuity or voltage. I noticed it tees off into the heater relay , does that play a part ? I can see fried wires behind the heater relay Quote Link to comment
datzenmike Posted July 13, 2017 Report Share Posted July 13, 2017 IF it is wired correctly it's either the alternator or the regulator. These can be tested at places like NAPA. I can only assume the wiring is correct. I can see fried wires behind the heater relay I think you have answered your next question. Quote Link to comment
ka620' Posted July 13, 2017 Author Report Share Posted July 13, 2017 Im pretty sure its right ive followed the diagram on that link you posted. I can tell you where they all go if your familiar with the harness. Where does one acquire a heater relay ? Parts store said they dont carry it Quote Link to comment
Crashtd420 Posted July 13, 2017 Report Share Posted July 13, 2017 Well first thing the the white and red goes to the light on the dash so if the voltage regulator doesn't see the alternator working it won't output 12 volts to turn the light off.... 2nd that yellow wire should be connected directly to the voltage regulator From the altenator.. nothing else should be hooked to it... ok scratch that.... it is in fact connected to the heater relay on a 620.... It looks like all it's doing is turning the relay coil on and off, its not the main supply power.... I think the yellow is the voltage signal telling the regulator the altenator is running , it probably the signal it uses to maintain a certain voltage which is enough to trigger the relay. So if you had an over voltage happened and you fried that heater relay that yellow wire might be receiving ground via the relay.... If what you say about your set up Is right and you get 12v where I said. I would either make sure nothing is attached to that yellow wire, and see if you get continuity or disconnect both ends of that yellow wire and run a new one between the alt and the regulator.. and see if it that works to make the alternator charge.. And that heater relay you can always wire in a generic automotive relay to replace it.... I can explain that later if needed.... Quote Link to comment
ka620' Posted July 13, 2017 Author Report Share Posted July 13, 2017 I snipped the yellow wire going to relay and saw no difference. Still no continuity or charging taking place.. Quote Link to comment
ka620' Posted July 13, 2017 Author Report Share Posted July 13, 2017 The wire on relay that is fried is white blue Quote Link to comment
ka620' Posted July 13, 2017 Author Report Share Posted July 13, 2017 Also i dont have the fusible link wired in right now , but thats just for saftey right ? Quote Link to comment
Crashtd420 Posted July 13, 2017 Report Share Posted July 13, 2017 I would try bypassing that yellow all together.... run a completely new wire... What year is your 620.... seems like there are slight variations to the wire harness year to year..... Quote Link to comment
Crashtd420 Posted July 13, 2017 Report Share Posted July 13, 2017 Also i dont have the fusible link wired in right now , but thats just for saftey right ? Yes... Quote Link to comment
Crashtd420 Posted July 13, 2017 Report Share Posted July 13, 2017 Yes... Ok I think you mean the fusable link on the white wire leading back to the battery... but do you have something connecting that circuit? Quote Link to comment
ka620' Posted July 13, 2017 Author Report Share Posted July 13, 2017 Fixed it , the two wires that plug into the alt (yellow, white/black) were backwards. Switched them around and the alt started right up. Thank you guys for sharing the knowledge! I Wouldn't have gotten it done without you guys. Quote Link to comment
Crashtd420 Posted July 13, 2017 Report Share Posted July 13, 2017 Nice.... sometimes something so simple can be such a pain in the ass.... You good on fixing that heater relay? Quote Link to comment
ka620' Posted July 13, 2017 Author Report Share Posted July 13, 2017 Man i was just sitting here laughing at the fact that it was something so simple.. whats the heater relays purpose ? Automatic choke and heater ? Quote Link to comment
Crashtd420 Posted July 13, 2017 Report Share Posted July 13, 2017 Not sure ... I actually have a 521, so some of the wiring is different.... my uneducated guess is yes.. I'd have to look something up to be certain .. do you have an electric choke on your carb? Quote Link to comment
ka620' Posted July 13, 2017 Author Report Share Posted July 13, 2017 Yeah i do and its not working Quote Link to comment
ka620' Posted July 13, 2017 Author Report Share Posted July 13, 2017 Yeah i do and its not working Quote Link to comment
Crashtd420 Posted July 13, 2017 Report Share Posted July 13, 2017 Let me get home and I'll help you out... just got in my truck Quote Link to comment
ka620' Posted July 13, 2017 Author Report Share Posted July 13, 2017 Cool , thanks man. Also , what gauge are you guys using for the fusible link ? Quote Link to comment
Crashtd420 Posted July 13, 2017 Report Share Posted July 13, 2017 Someone else will have to answer that.... I went a little overkill on my main power... relocated the battery... I used 8gauge coming off the altenator, I forget what size fuse... As far as the relay... you should have 4 wires.... Something like this... Yellow and black are the coil which activates the switch .. the other 2 one is gonna be power and one goes out to the carb.... This is a standard automotive relay... 85 and 86 are the coil.... connect the yellow and black to those 2.. Then 30 and 87 Will be the other 2 wires.. Quote Link to comment
Crashtd420 Posted July 13, 2017 Report Share Posted July 13, 2017 How bad were the wires at the relay? Do you still have power there? Quote Link to comment
ka620' Posted July 13, 2017 Author Report Share Posted July 13, 2017 Ok forsure thank you. Do u know what specific wire goes to wich number ? its just one wire completley disconnected at the relay. It has power to the wire but its not going into relay. Quote Link to comment
Crashtd420 Posted July 13, 2017 Report Share Posted July 13, 2017 What are the 4 wires colors you Have? And which one is showing power... Quote Link to comment
Crashtd420 Posted July 13, 2017 Report Share Posted July 13, 2017 Is the stock setup repairable? If not and you switch to the other style relay 85 and 86 can be either the yellow(power from alternator) or the black(should be a constant ground)... this activates the relay. 30 and 87 are the switch when it activates the circuit is connected ... that should connect power to the choke... not sure what those 2 wire colors are, and they can go on either 30 or 87 doesn't matter.. Quote Link to comment
datzenmike Posted July 14, 2017 Report Share Posted July 14, 2017 The choke heater relay requires a charging alternator in order to be on and sending power to the choke heater. Basically a charging alternator tells the relay that the engine is running, and here's why.... In cold weather engines are very hard to start, keep running and drive without a choke. So one very cold morning you go out and start your truck and go inside while it warms up and finish you 4th cup of coffee. Unknown to you the engine stalls, but without the relay, the choke heater continues to warm the choke, turning it off. You go out 10 min later and the engine is stone cold and your choke is off. Starting and running it now will be very difficult. With the choke heater relay, as soon as the engine stops the relay shuts off and the choke does not warm up and stays on. Quote Link to comment
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