[Nick Spano (74chall)]

Hello, been having some problems getting my charging system to work. Brought the alternator and got it checked out, it's fine, 85 amp's. Brand new Interstate battery. Checked the voltage regulator and power is coming in and out of both wires.Is there any sure way to check if the voltage regulator is bad. I also have a new ballast if that matters. Open for other suggestions to what can be wrong. Thank you , Nick

[Dave-R (Roppa440)]

I have been busy Nick. Are you still having problems with this or is it sorted?

[Nick Spano (74chall)]

I figured it out, I just took the chance and replaced the regulator and it's carging now. Thanks

[Amy Douvlos (Douvlos)]

Hi. It's me again, Amy. I am still having charging problems with my Challenger. As stated earlier, I have replaced the alternator, voltage regulator, electronic ignition box and ballast resistor. I have not replaced the battery, but always charge it to full capacity before trying to perform any tests. Someone was kind enough to send me a wiring diagram for the 1973. Does anyone have the 1973 Chassis Manual for the Challenger that can get copies of all of the charging system tests to me?

I think that that is where I need to go from here. I checked continuity from the battery to the left side of the ammeter which was good, and the alternator output to the right terminal of the ammeter wich did not give me good results.

If anyone can help me, I'd appreciate it. And I am willing to pay for your copying services.

Thank you,

Amy D.

[Dave-R (Roppa440)]

Start the car and warm it up. Increase the rpm of the engine to about 1500rpm (with the idle speed screw) and put your voltmeter over the battery.

Tell me what exact voltage it reads.

[Dave-R (Roppa440)]

Then switch everything off, put the headlights on for a couple of seconds and then switch them off too.

Measure the voltage accross the battery again with everything off.

Tell me exactly what the voltage is.

[Amy Douvlos (Douvlos)]

Hi:

This is Amy again. I made a probe to check the wiring/connections for my charging problem on my Challenger, and cleaned the wires - especially from the battery to the firewall so I could identify them. Then when I went to start the car - NOTHING! What a disaster! Another problem. The key turns and nothing. But it will start if I use a screwdriver and touch the two nuts on the (solenoid?) junction near the battery where the battery cable, starter cable, etc. come together. Now what? Do you think that this is where my whole problem is (starting and charging)? Should I replace it and go from there, or do you think I jiggled something loose at or near the firewall? Or do you think the ignition switch is at fault? Please give me some guidance and this is driving me crazy and I think you'll soon see another Challenger for sale.

Thanks.

[Douglas Little (Dlittle)]

This is not a big problem. It happens a lot. The relay you by passed to start the engine is activated by a ground when the transmission is in park or neutral. Some times the hook up at the relay needs cleaning or the connector to the transmission harness. As this area was just work with it may be that a connection has been disturbed. It should have nothing to do with the charging problem. I would check for the charging problem from the alternator back to the battery rather than the battery side first. Go back over the area you cleaned and double check any connections that may have been disturbed. It seems unlikely that parts are failing while you are trying to solve the charging problem so I would not replace any more parts that have not proven themselves defective.

[Amy Douvlos (Douvlos)]

Doug:

Thanks for your response on my issue. I did run a jumper wire from the alternator output to the "B" terminal on the starter relay, then checked the battery voltage which increased. Any possibility that that burned out my ignition switch? The wiring that I cleaned was from the starter relay to the bulkhead at the firewall, where I was going to perform my next test. At this point the ignition switch would not crank the engine. And I did notice that one of the wires that clip onto the starter relay was off so I reconnected it. But no go. Any other thoughts on this matter please?

[Douglas Little (Dlittle)]

It is tough enough to chase a wiring problem even with hands on so help from here must be taken accordingly. Remember when making repairs, "first do no harm". I take it that the charging problem has been superceded by the failure of the ignition switch to start the car. Dave has posted some great wiring diagrams that I would down load and look at closely before chasing problems much more.

As fare as the starting problem goes, if you can start it at the relay by a by pass (power to the starter solenoid) then the relay will come into play. If you can ground out the relay wire that goes to the transmission and the car starts then the wiring or the safety switch at the transmission is at fault (but unlikely). Check again the wiring. When checking at the key switch make sure it is in park or if not try neutral. Check the relay to see if it is recieving power by turning the key to start. This should be possible in any gear. If you do ground out the safety switch remember the car will start even if in gear. If there is no power to the relay, check the connection at the harness from the steering wheel to the dash harness. If all this fails to find the problem it may be the key switch. I sure hope not. Any chance of some pictures of the problem area?

Dave, if I am running down the wrong path here please jump in before any harm is done. I am a shade tree mechanic at best and I know there are lots of you that can handle this problem in your sleep.

[Dave-R (Roppa440)]

I think hands on help is needed now. Everything Amy needs to know is right here.
I have given the best instructions I can without physically doing the job myself. I don't know what else I can do.

Amy has to take a methodical and logical series of steps to trace one fault at a time. I am not an autoelectrician or a mechanic. I only know what I would do myself. Obviously this is because I have a basic understanding of electricity. I realise many others do not and it must almost seem like 'magic' to some people I know!

Amy has to attach one probe of the meter to chassis/ground and use the other to follow the wire from the battery or alternator until voltage is read or voltage is lost (whichever matters not). The fault is there at that point.

The more you think it may be this or it may be that - the more confusing the whole thing is.

I had a local friend once with a few electrical problems like this. I helped him as much as possible over the phone but he got no-where.

When I finally saw the car there was wires twisted together or falling apart everywhere. A burnt out section had been 'repaired' with a length of coat hanger wire twisted at the ends. The wires for the ballast resistor were connected to the oil pressure switch. No wonder non of my instructions were any use! But with him not being 'an electrician' he could not see anything wrong with this.

So my final word on this is that if Amy has spent all this time and effort trying to find a bad connection and failed then I think the time has come to get someone to look at it that knows what he/she is doing.

[Dave-R (Roppa440)]

And I say to Amy if what I just wrote makes you mad then get back at me by finding this fault and rub my nose in it!

[Douglas Little (Dlittle)]

I build electric boats for money (can't make any on cars, they only take it). I helped a customer with an electrical repair over the net and by phone. It was long, stressfull and damaging to good components. The one thing that made the repair possible were photos of the wiring. The mistake was found and corrected. Like Dave said, you have to see it to really know what is going on. It may not solve the problem but a picture is worth a thousand words. Is a photo possible Amy?

[LITEMUP]

I believe the wire from my alternator that charges my batt. is part of the problem. i dont think its big enough. I am going to attempt to run a larger gauge wire directly form the alt to the batt. will this create problems and should i do it?

[dave-r]

Sounds like a good idea. It will not do any harm to try.

[71_DEPUTY]

Amy- check the two large wires that go to the firewall harness.
they are the worst trouble makers due to that the spade terminals are only really go to about 40 amps of current. after that they start to heat up and then get even worse with time. all my cars I have relocated both wires through another hole in the firewall with a rubber groment- this prevents this kind of problem when large amounts of current is needed to charge the battery, lights, heater and big kick a** sterio systems.

make sure that the terminals are real clean and fit tightly onto each other when the plug is put back in.

here is a Imperial site that I like to pass on- it should help you to under stand the wiring troubleshooting part.

http://www.imperialclub.com/Repair/Electrical/index.htm

and here is a pic to help you see where to use a meter.

http://www.imperialclub.com/Repair/Lit/ ... 6/back.htm

let us know if we can help anymore!!!!


John mac