Cleaning up engine bay wiring. Have ?’s

[Just Joel]

OK, background is that about two years ago I tore down the engine bay in my 71 510 wagon and cleaned, shaved and painted everything. Now that I'm putting it back together, it’s time to reinstall the wiring harness. I'm swapping in an l20b with IR alternator, matchbox distributor and a 5 speed in place of the stock l16 and 4 speed. I figure while I'm cleaning up everything else in the engine bay, there’s no point in reinstalling the harness with useless wires left over from the points distributor, voltage regulator and stock transmission. So with the help of a color 510 wire schematic (thanks ratsun ;) ) I have unwrapped, cleaned and identified each wire. So now it’s time to start removing relays and wires I will no longer be using, which leads to my questions...

 

1) On the schematic, I see that there are multiple switches and solenoids that I think are located on the transmission. If they are, do I still need them and will the five speed have similar wiring and switch locations as the stock 4 speed?

 

2) For the electronic distributor, the wiring diagrams I have found for the conversion say to connect the coil + to both ignition "on" and "start" power. It looks to me that the wiring schematic shows that the two wires connected to either side of the points ballast resistor come from such sources... is this correct?

 

3) Also, since I'm eliminating the points distributor, do I still need the relay and the carb switch?

 

 

Sorry if these are lame questions but after reading for hours and searching the entire site for info, I'm still unsure of these things.

 

Thanks

Joel

[Just Joel]

One more question, I have also read that when upgrading alternator size, you should also upsize the wire and fusible link between the alternator and starter motor. Is this true and if so what size should I make them?

 

 

Thanks

Joel

[DanielC]

These are the switches that are on a stock 510, four speed manual transmission. Throttle pedal switch, throttle position switch on the carburetor. A switch on the clutch pedal, a switch for third gear, and a switch for neutral. All the switches are to control a relay, that puts the retarded set of points into the system, and this makes the engine run on the retarded set of points, on the stock dual point distributer.

With a matchbox distributer, you have no second set of points. So most of the switches, and the relay become useless.

When I swapped a five speed in my 521, there was only a reverse light switch on the transmission.

 

I have my matchbox distributer wires to get power through the ballast resistor when in run position, and bypass the ballast resistor when cranking. This is because I am still using the original stock points, "use with ballast resistor" coil.

[Just Joel]

So all the switches and solenoids in question are now obsolete for my application and I can remove the wiring from the harness with the exception of the backup light switch? I assumed originally this switch would be maintained...

 

And I can remove the resistor so long as I use an ei coil and run those two wires together to the + post on the coil, correct?

 

Thanks

Joel

[banzai510(hainz)]

And I can remove the resistor so long as I use an ei coil and run those two wires together to the + post on the coil, correct? Only if you have a matchbox dizzy!!!!!!!!!

 

You read Olddatsuns.com Jasone Grays write up?ignitions

 

I runa 50amper and I dont do anything with the fuseable link!!!!!!!!!!!!You have a battery to store the extra energy in case it draws to much current thats where it comes from. If concerned You can route a bigger wire from output alt to the starter lug/battary

 

only wires you need is the

Blk /wht key ON

Blk/blu is 12volt START. Youll short this with the blk/wht at the + side EI coil

 

matchbox

B + side coil(12volts)

C -side coil

 

 

the HOW TO section also has it on here

[Just Joel]

And I can remove the resistor so long as I use an ei coil and run those two wires together to the + post on the coil, correct? Only if you have a matchbox dizzy!!!!!!!!!

 

Correct, I mentioned that the swap included a matchbox dizzy in my first post but I was only looking for clarification as to needing a resister after Daniel's response.

 

You read Olddatsuns.com Jasone Grays write up?ignitions

 

I'm not sure if I've read that one... I'll look it up.

 

I run 50amper and I don’t do anything with the fusible link!!!!!!!!!!!!You have a battery to store the extra energy in case it draws too much current that’s where it comes from. If concerned You can route a bigger wire from output alt to the starter lug/battery

 

Cool, that answers that question ;)

 

only wires you need is the

Blk /wht key ON

Blk/blu is 12volt START. Youll short this with the blk/wht at the + side EI coil

 

matchbox

B + side coil(12volts)

C -side coil

 

 

the HOW TO section also has it on here

 

This is the schematic I referred to earlier, sorry I didn't post it then...

 

 

This is where the confusion is from on my part, It shows both power sources connected to the + terminal. So you’re saying all I need is the wire from the power "on" source?

 

Thanks

Joel

[Just Joel]

Here is the wiring instructions that were included with the above diagram. Do I need both wires or just the black/white ignition "on" wire as Hainz explained?

 

"Wiring for the matchbox distributor consists of two wires from the coil to the ignition module on the distributor, and a key switched 12V power source to the positive side of the coil. The wires from the coil to the distributor must be connected as shown, and not reversed. Also, the coil should receive 12 volts while the starter is being cranked, and when the key is in the "on" position. For some vehicles this will require that two separate wires come from the ignition switch (as shown in the wiring diagram). This is because vehicles that originally had a ballast resistor have a separate circuit to provide 12 volts directly to the coil during engine starting."

 

Thanks

Joel

[Just Joel]

Also, I went to Olddatsuns.com looking for Jasone Grays write up but the link no longer works on old datsun's site.

 

Thanks

Joel

[kgrantkey]

Here is the wiring instructions that were included with the above diagram. Do I need both wires or just the black/white ignition "on" wire as Hainz explained?

 

"Wiring for the matchbox distributor consists of two wires from the coil to the ignition module on the distributor, and a key switched 12V power source to the positive side of the coil. The wires from the coil to the distributor must be connected as shown, and not reversed. Also, the coil should receive 12 volts while the starter is being cranked, and when the key is in the "on" position. For some vehicles this will require that two separate wires come from the ignition switch (as shown in the wiring diagram). This is because vehicles that originally had a ballast resistor have a separate circuit to provide 12 volts directly to the coil during engine starting."

 

Thanks

Joel

 

From what I just read you understand exactly how it should be wired. And you are correct in the schematic it shows how both wires hot with ign & start are connected together because the ballast resistor has been removed.

 

So you only need the Black/white wire to the coil. I think the reason they are tied together in the schematic is so you have a place to terminate the (hot start) wire rather than have it hanging loose.

[Unclejesse88]

you will only need to upgrade the b+ cable that runs from your new alt to the starter. When I installed my 60 amp, I used a section of cable I got from work that came out of a newer ford fusion. The cable size was most likely 6 or 8 gauge, which is overkill, but it was free. I used it mainly because there were already fusible links in the cable, two 14 gauge fusible links in parallel. You will want to run fusible links in your upgraded charge cable, just in case the alternator shorts out internally or your cable chafes through against the block or something of that sort.

[Just Joel]

From what I just read you understand exactly how it should be wired. And you are correct in the schematic it shows how both wires hot with ign & start are connected together because the ballast resistor has been removed.

 

So you only need the Black/white wire to the coil. I think the reason they are tied together in the schematic is so you have a place to terminate the (hot start) wire rather than have it hanging loose.

 

thank you, this makes more sense ;) now that I think about it, the "start" wire delivers twelve volts only at start up and the stock coil is sustained by the "on" wire that runs through the resistor. In an ei setup, the "on" wire already delivers twelve volts all the time so there is no need for the "start" wire.

 

Thanks

Joel

[Just Joel]

you will only need to upgrade the b+ cable that runs from your new alt to the starter. When I installed my 60 amp, I used a section of cable I got from work that came out of a newer ford fusion. The cable size was most likely 6 or 8 gauge, which is overkill, but it was free. I used it mainly because there were already fusible links in the cable, two 14 gauge fusible links in parallel. You will want to run fusible links in your upgraded charge cable, just in case the alternator shorts out internally or your cable chafes through against the block or something of that sort.

 

Thanks, if I upgrade the cable, should I leave the fusible link stock. The stock wiring only has one fourteen (I thinkthat's the size) fuse in place.

 

Thanks

Joel

[Unclejesse88]

fusible links are usually two or four gauge sizes smaller than the wire they protect

[DanielC]

fusible links are usually two or four gauge sizes smaller than the wire they protect.

And they have insulation that does not burn.

[hogboy52]

Have you now decided that you only need the "on" wire to the coil and not need the "start" wire also connected at the coil? I am pretty certain that the start position is connected to the starter solenoid and coil only. The radio, wipers and other accessories including the "on" wire to the coil are turned off.

[Just Joel]

Yeah, after looking at the wiring diagram and other sources, it appears that the "on" wire (black/white) has power both in the "on" position and "start" position. From what I can tell, it looks like the second wire runs to the other side of the ballast resistor to deliver a full 12v during start up in a standard points type ignition but because the ballast resistor is removed during the swap to the ei ignition, the second bypass wire is no longer required.

 

Later

Joel