510 engine wiring harness

[islander]

had to change the wiring harness on my 1970 510 & now the starter is not getting the message from the ignition. had already changed to electronic ignition so there is no resistor. Got the heaver gauge black/white wire on the pos. terminal on coil ( power wnen ign. on) with the black/blue one ( power when in start postion) but get nothing from the black/yellow one to the starter. Will start if i add jumper wire from the black/blue wire to the starter. Thinking it has to do with neutral / clutch wires? have  2 black wires, 2 black/yellow wires & a blue/black wire (kick down?) going to tranny but not hooked up. tried connecting all the black & black/yellow ones together but did nothing. Got a switch by clutch pedal, but no wires on it. Any ideas how to get to work proper?? will it b ok to just add jumper wire if all else fails?? Do not like wiring, so any help would b great !!

[datzenmike]

There are two START signals. One goes to the starter solenoid and is Black/Yellow from the ignition switch. The other wire, Black/Blue goes to the coil positive terminal and during start provides a full 12 volts to the coil (around the ballast) for a hotter spark while cranking. They are not connected togethe at the ignition switch.

 

There is a single, Black/White,  ON or RUN wire from the fuse box that goes to the ballast. It hot ant time the ignition is on.

 

 

If you have an EI distributor the Black/Blue (start) and the Black/White (on) should be joined together and go to the coil positive terminal and the B terminal on the matchbox.

 

(ignore the 1.6 ohm coil)

 

If no power on the Black/Yellow check at the ignition switch. 

[islander]

thanks for the quick reply. thats just the way had it with the black/white & theblack/blue together on pos. coil side.except instead of match box mine is bigger (4"x3") did work before harness swap. checked all connections. not getting power to black/yellow on starter. switch is good,workes when i remove the black/blue from coil & connect to starter.If seeing is beleiveing m just off 17th street if u have time for house call sometime, will gadly have cash.Glad u know what m talking about & keep trying, any other suggestions.plugged & unplugged connections on harness few times.

[islander]

the one difference between the olds engine harness & the replacement is that,there is one extra wire where it plugs into dash harness.its a plug containing 3 wires . on the engine side it has a green/yellow ,yellow/green & a blue/black one. the dash side does not have the blue/black wire. the old harness did not have blue/black wire . there was just an empty spot in the plug. could this b the problem ??

[datzenmike]

4 hours ago, islander said:

thanks for the quick reply. thats just the way had it with the black/white & theblack/blue together on pos. coil side.except instead of match box mine is bigger (4"x3") did work before harness swap. checked all connections. not getting power to black/yellow on starter. switch is good,workes when i remove the black/blue from coil & connect to starter.If seeing is beleiveing m just off 17th street if u have time for house call sometime, will gadly have cash.Glad u know what m talking about & keep trying, any other suggestions.plugged & unplugged connections on harness few times.

 

Yes the remote igniter EI.

 

The Black/Yellow on the starter solenoid goes back to the ignition switch. Expose the ignition switch and find the Black/Yellow wire and check for power when the key is turned.

 

 

Couple of houses south of 17th on Fitzgerald? Do you know Ted Moonan? or maybe it's his son Cameron??? 

 

When are you home?

[banzai510(hainz)]

I worked on a guys 510 and he changed a harness and had the connections wrong under the glove box area. I guess there is a couple connector that can be swapped

 

not all harness in btween the years are exactly the same but I think the ignition parts would be the same

Edited May 24, 2021 by banzai510(hainz)

[islander]

Thanks for the reply. Yes u r right the r not all the same. got another complete harness engine & dash & will try this one, except it has 7 plugs by glove box & the other had 6 plugs. got my fingers crossed & hopefully not my wires!!

[banzai510(hainz)]

Oh by the way if one isharness is from a automatic it needs to be jumperes I believe in 2 places otherwise it wont start also

 

 

what was wrong with the orginal harness?

Edited May 24, 2021 by banzai510(hainz)

[islander]

just about to head into the garage now. going to c if the is power to the black/yellow wire @ ignition, as Mike suggested & take it from there.The original harness got fried , mostly ground wires by voltage reg. That happened on my attempt to wire a saturn alt. in. Mixed-up wires, but found the mistake. M sure the electrial gods do not like me!!

[banzai510(hainz)]

4 minutes ago, islander said:

mostly ground wires by voltage reg.

those can be spliced in and fixed

[islander]

thought about tring to fix old harness, but was burnt bad,not just the plastic but wires burnt in half & unsure how fare damage went. Checked & got power to the black/yellow wire @ ingntion when in start postion but getting no power to black/yellow @ starter? Going to try & get it working proper, but thinking of adding jumper wire from black/blue wire that went to coil to the starter.This makes it work for now. Will keep @ it.

[banzai510(hainz)]

do not add jumper wire  that is hoky

trace the starter wire back to the glove compartment to the key switch

 

like I said if this harness came from a AUTOMATIC you need to short out the areas where the trans switch was at

 

soem 510 under the fuse box had 2 bus bars and another only one

 

 

this is exactly the same when I was working on this guys cars No starter 12volts. It was in glove box connector wrong

Edited May 24, 2021 by banzai510(hainz)

[islander]

good advice. Dont want hoky riding in my car. Yea u must b right, seem its not making right/ good connection ther by glove box. Been looking @ old harness and think i will make atempt to fix it. So what did u do to fix buddy car with that problem?

[banzai510(hainz)]

he said he plug the right connector in the right spot. It was his mechanic that was saying just make a jumper wire. I said no there got to be soemthing. He had another spare harness also he was going to swap in.

[islander]

did check the connection & all the colours did match EXCEPT for one extra blue black wire on a 3 wire plug. So its not an exact match. Not sure what u mean by bus bars under fuse box? Will take my time with repair(need coffee) on original harness & let u know how that goes. Thanks !

[islander]

well took my time & fixed old harness. Sodeird & used shrink tubes on all my connections & everything seems to b working as it was. Dont know if the replacement was for automatic or what the problem was, but just happy to have it working as it should without hoky. frustration level was getting high, so thanks for your suggestion to fix old harness. U guys r the best !! and happy motoring.

[banzai510(hainz)]

Just buy a 50/ 60 amper alt and dont worry about those Saturn alternators!!!!!!!!!!!!!

 

just make sure it says 50/60 amper for a L16 510 as the bolt holes are small on the L16

If you have a l20 you order a say 1975 alternator of a 610/710 that had a L20 in it

[yenpit]

22 hours ago, islander said:

well took my time & fixed old harness. Sodeird & used shrink tubes on all my connections & everything seems to b working as it was. Dont know if the replacement was for automatic or what the problem was, but just happy to have it working as it should without hoky. frustration level was getting high, so thanks for your suggestion to fix old harness. U guys r the best !! and happy motoring.

 

The early 1970 harness is first 6mo's production only.  Would not plug into a later 70-72.  The later 1970-1972 are basically the same.  The 1973 is also a 1 year only harness.

 

I bet you had an automatic harness..........car will not start unless you jumper wire where the auto neutral safety switch was (a small sub harness from where the wiper motor is located, down to the trans). 

 

Did you replace the dash harness as well?  All harness sections had a white plastic tag with a part #.  Unfortunately 99% of the engine compartment harness tags fell off, cuz they were on the harness below the radiator, so out in the weather!  The dash harness tag is usually intact, cuz inside the car.  That said, you can check the dash harness part # online to see what year & model.

[islander]

hey there, found the white tag, but cannot make out the #. For future referance, if it was for an automatic, what wires would need to b connected? The colours on the wires going to trans are; 2 black,2 black/blue & one blue/black.Dont have the sub harness.Tried looking @ wiring diagram, but was no help to me.

[datzenmike]

Black/Yellow from START position on the ignition switch goes to the auto interlock switch which connects them if in PARK or NEUTRAL allowing you to start. There should be an engine sub harness with the reverse light switch, interlock switch and probably a 3rd gear switch wiring, if a standard, passing over the starter motor going to the transmission. The oil pressure warning light wire will also be on this harness. Just splice the two Black/Yellow wires to complete the circuit in the start position.

[islander]

Well then that all makes sense now. M amaze how much u guys know.Sure glad i got on this site. got my dash all back together,so will stick to the old manual harness for now. The clutch switch is not connected.Would u know what wires should go to it. the car has been peiced together, but think got a manual dash harness.Still got to check into the reverse lights too. Its got a 5-speed now.Just havent look,not too much of a concern now. And hey Banzai 510, in highen sight yea should have went with your suggestion,it would have been alot easier, its just that been reading bad stuff about SOME of the re manufactured ones.Any other ideas i have, will put it out there first!! Anyway as they say alls well that ends well.

[islander]

been looking @ the wiring diagram sent to me by demo 243 & its all starting to make sense now.Did look earlier but didnt quite get it.Now it seems clear& think found answers to my own questions-looks like b connecting the green/yellowwire to one side of clutch swicth & the green on other end. And the blue/black wire spoke of earlier by glove box was for manual trans. Didnt get it earlier but now not only got the answers but understand it much better now.Dont think could have done it without all your help. Cheers!!

[yenpit]

On 5/26/2021 at 12:42 AM, islander said:

been looking @ the wiring diagram sent to me by demo 243 & its all starting to make sense now.Did look earlier but didnt quite get it.Now it seems clear& think found answers to my own questions-looks like b connecting the green/yellowwire to one side of clutch swicth & the green on other end. And the blue/black wire spoke of earlier by glove box was for manual trans. Didnt get it earlier but now not only got the answers but understand it much better now.Dont think could have done it without all your help. Cheers!!

 

I think that clutch switch was an emission switch........??  Maybe had to do with the dual points switch box??  Pretty much useless on a 50 yr old car!

 

Did you figure out the automatic neutral safety switch jumper wire, or you did not need to do it?  I wrote up a thread here on how to do it 9-10 yrs ago, but can't remember which wires at this point!! 😣

[islander]

did not use the wires for the emission stuff, throttle wire or the dual points. Got a electronic ignition & a holley carb with throttle cable.Did not have to use a jumper wire for the neutral safety switch, think i have a manual wiring harness on the car.Still have the issue of the car starting in gear with clutch out (5 speed manual). Have not had time to look @ this yet but hope to fix it proper.ALL other electrical stuff is working great,Quite happy. took car in for wheel alinement on Thurseday,& got insurance. FIRST time in 30 YEARS, car has been on the road!!

[banzai510(hainz)]

15 hours ago, islander said:

Still have the issue of the car starting in gear

Mine will start in Gear!!!! Matter of fact all manual transmission 521/ 510s will start in gear