Electrical experts please help me this wiring is driving me nuts! - Team Camaro Tech
Electrical & Wiring Troubleshooting electrical.

 
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post #1 of 8 (permalink) Old Aug 18th, 02, 01:20 PM Thread Starter
JMD
 
Join Date: Mar 2002
Posts: 9
Heys guys Im running out of hair to pull,so Im going to see if you guys can figure out what is going on.
First lets start off by saying I have a 69 camaro that used to have an L6 and a points type ignition,but now has a v8 with a GM HEI ignition. Also while the L6 was still in the car I did the external to internal si series alt. swap and everything worked fine or so I thought.

Also when I upgraded to the V8 and the elec. ign. I did all the stuff required like straight 12 volts to the dist. via a knew 10 gauge wire from the ign spade terminal in the fuse box and also put a relay inline to make sure constant 12 ,and I put the batt. in the trunk and ran 2 gauge wire from the trunk to a remote ford type solenoid,then to the starter.

Now for the problem I went to fire up the motor fr the first time everything worked fine,when I finally got the thing to idle and went to pull the key out Ill be damned if it kept on runnin,but everything is charging like it should be.
So I grabbed my meter to try to figur things out and what I came up with is that for some reason after the ign. is switched off and the motor is still running Im getting "2" volts to the relay to the dist. which I guess is enough to keep the thing energized so it will keep sending 12 volts to the coil,and also Im getting "2" volts to the fuse box at that time.
So Itryed some more experimenting and found that if pull the 2 wire connector out of the alternator whilethe car is still running with the ign. shut off it will die .
I read all the archive posts on alt. backfeed and still couldnt figure out if that was my problem or not so i started to tear into the factory harness and decided to rewire somethings to do away with the hole mess there around the horn relay.
So heres what I did
Ive got the main wire that bolts onto the back of the alt. going straight to the hot all the time side off the starter relay. Then The to wire connector coming out of the alt. (that I got from autozone that has a red and a white wire on it)The red wire going to the output stud terminal on the alt,and the white wire connected to the navy blue wire on the factory harness then its jumpered to the brown old external regulator wire.Then to illiminate the horn relay(ill figur out what to do with the horn later),I ran a 6 gauge wire from the batt. to the fuse box were it feeds everthing,because that wire originally came from the horn relay buss bar.
And I took all the dead wires out off the harness that werent being used anymore like the coil wires yellow starter wires and so on.
Did all this fired it up same problem with the 2 volts only now the gen light comes on but real dim and I noticed that with motor running key on ive got about 15 volts output at the altand when I turn the key off and the motor keeps running Ive only got about 12-13 volts at the alt.

Does anybody have any ideas?
Ive heard about the diode thing is that what I need if so were does it go?
I know I could put in a toggle switch in the ign coil circuit but I really dont want to.

Anybody with some ideas please help me its driving me crazy.
Sorry My posts so long I dont know how to draw a schematic on the computer.

Almost forgot whats the pink wire with the black stripe for going to the horn relay.
Thanks fo any help.
John
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post #2 of 8 (permalink) Old Aug 18th, 02, 04:06 PM
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Mark
 
Join Date: Feb 2002
Location: LR AR
Posts: 2,372
I can't help too much here but I can tell you I had the same problem when I added a Crane CD ignition. I needed a diode for the external voltage regulator wiring. The diode is like a one way electrical check valve. Power goes only one way with one of those in the circuit. Since you have converted to an internaly regulated alternator, my exact fix would not apply to you but the idea is probably valid. Hope this helps in some way to stimulate a solution.

-Mark.
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post #3 of 8 (permalink) Old Aug 18th, 02, 04:59 PM
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Mike
 
Join Date: Jul 2000
Location: Poway (San Diego), CA
Posts: 193
You need the diode in the alternator wiring, it doesn't matter if it is internally regulated. I had to add the diode to my system and I have an internal regulator. BTW, I had this problem as well when I first fired up my engine. Just by luck I came across the solution in my MSD instruction manual.

Mike

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94 Z28 Convertible
68 Camaro SS Clone
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post #4 of 8 (permalink) Old Aug 18th, 02, 05:02 PM
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Mike
 
Join Date: Jul 2000
Location: Poway (San Diego), CA
Posts: 193
Oh, btw, the diode goes in line with the white wire on the alternator.

Mike

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94 Z28 Convertible
68 Camaro SS Clone
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post #5 of 8 (permalink) Old Aug 18th, 02, 06:10 PM Thread Starter
JMD
 
Join Date: Mar 2002
Posts: 9
Thanks guys I figured it would problably be the diode ordeal.
Hey ChevyCam when your talking about the white wire do you mean the white wire on the new pigtail that you get from part stores to plug into the alt.. Which if my pigtail is the same is yours you connect the white wire on the pigtail to the blue wire on the factory harness.
Also as far as the diode goes I work at autozone and could always "accidently" open the MSD 6al box and look at the diode to see what were talking about and then look elsewhere for on at radio shack or something but is there a certain one or part# to get?
Is there a special way to install it?

Why does this Alt. backfeed happen it almost seems like the diode is covering up other problems,or is this just one of te joys of owning a 33 year old car.

Thanks again guys
John
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post #6 of 8 (permalink) Old Aug 18th, 02, 07:09 PM
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Join Date: Feb 2002
Location: Williamstown,PA
Posts: 500
Just a thought but why didn't you just eliminate the relay on the HEI? I've hooked quite a few of these directly to the IGN terminal on the fuseblock and NEVER had a problem. If you insist on the diode it's a 1N4001 or Radio Shack cat.# 276-1101. Install it between the white wire on the new alt. plug and the blue wire on the old harness with the striped end of the diode toward the blue wire.

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'69 RS Camaro
355 5-speed 4.11
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post #7 of 8 (permalink) Old Aug 19th, 02, 10:45 AM Thread Starter
JMD
 
Join Date: Mar 2002
Posts: 9
Thanks 1 2Run that was the diode information I was looking for.
As far as that relay inline,the relay Im using is some kind of high amperage battery isolation relay thats triggered buy the spade connector on the fuse box then it supplies juice to an Aux fused distribution box that Ive added for all off my swithched accesories. Some guy that does alot of stereo installs send it would be a good idea because its kind of adding another ign on circuit.
So actually when the key is off and the engine still running the high amperage relay is keeping everything on the distribution box running.

What Im wondering is could I have had this alt. backfeed problem when I converted alt. originally with the L6 only I didntknow it because there was no relay affecting the ign coil?

Thanks again guys for all your help.
John
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post #8 of 8 (permalink) Old Aug 20th, 02, 04:23 PM
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Join Date: Feb 2002
Location: Williamstown,PA
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The alt. light circuit is a tricky one. The bulb is connected at one end to the ignition switch and the alt. windings at the other. When the alt. is putting out the white wire becomes positive. Two positives won't light the light. When the alt. is not putting out the white wire is grounded through the windings and the light comes on. Since the newer style alt. is excited directly from the battery (red wire next to the white) the white wire stays positive until the alt. stops spinning. The fact that it back feeds through the alt. light usually doesn't cause any problems until you get something touchy like a relay coil.

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'69 RS Camaro
355 5-speed 4.11
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