Electrical problem
I have a 65 convertible. Off the frame, all new parts. Car is running and putting out to many volts. Right at 18 volts. Three new regulators, One had the points burned off. New alternator. Taken off and checked putting out 14.6 volts. The battery guage is going crazy. Will read plus 40 then spike to plus 100. Bounces all over the place. Then will go back to zero. Car does not run hot. Water temp is excellent. The alternator after running for 5 minutes is hot to the touch. The car starts right up, one revolution of the motor and runs great. After car gets hot exhaust starts to pop. IF you drive it its pop pop pop. Chased down the wires in the loom and all appear to be wired correctly. Anyone had this problem?
-
-
Re: Electrical problem
Welcome to the TDB, Mark.
The popping exhaust and charging voltage are likely separate issues.
Symptoms with erratic voltage point to a faulty regulator or a wiring issue that prevents the regulator from working properly. The question is why did three regulators fail? Were they defective when new? Or are they failing to work properly because of a wiring issue on the car?
When you say "Taken off and checked putting out 14.6 volts"... how did you run the alternator with its regulator off of the car? One method is to start the car, disconnect the alternator output from the horn relay buss (typically a 10R wire), then check voltage at the alternator output post. If the alternator and regulator work normally when isolated from the car, this points to a wiring issue in the car... bad ground, short, loose connection... that sort of thing.
Several things can cause exhaust popping. I suggest checking ignition timing first. As a test, disconnect the VAC, plug the vacuum line and see if that makes a difference. Then check and adjust initial timing.
Let us know what you find.Mark Edmondson
Dallas, Texas
Texas Chapter
1970 Coupe, Donnybrooke Green, Light Saddle LS5 M20 A31 C60 G81 N37 N40 UA6 U79
1993 Coupe, 40th Anniversary, 6-speed, PEG 1, FX3, CD, Bronze Top -
Re: Electrical problem
Mark, thank you for your reply. I have the third new VR on now. I took the alternator off the car and took it up to the auto parts store and asked them to test it. They put it on their test rig and got 14.6V. I will make the checks you suggest and report back. It is a new loom. We ran a ground jumper from the alternator and the VR and it didn't make a difference. I will check the points to see if they are fried or the dwell has changed. The dwell was at 29 when we tuned it. Thanks again for your help. I will report back.Comment
-
1966 L79 Convertible. Milano Maroon
1968 L71 Coupe. Rally Red (Sold 6/21)
1963 Corvair Monza ConvertibleComment
-
Re: Electrical problem
Thank you, Ill check that.Comment
-
Re: Electrical problem
Mark,
I have a known good spare alternator off of my '64. We live less than two miles apart, would youl like to try out my altermator?
JamesComment
-
Re: Electrical problem
I havent had a chance to work on the car but will tomorrow morning. The alternator is new. I took it out of the car and had it checked at an auto parts store. It was putting out 14.6 volts. When the car was at idle it charge at like 14 volts. When you rev it up it goes to 18. This was over at Jerry B house. Ran fine going over there. On the way home started to pop and at my house popped real bad. Im going to take the tape off the loom and see if I got a bad wire. I will let you know if another alternator might help. Thank you for the contact.Comment
-
Re: Electrical problem
I agree with Rich that a connection or wire placement in a terminal is wrong. I always check the harness to firewall fuse box connectors as issues may be found there.Comment
-
Re: Electrical problem
Well the problem is solved. believe it or not, I ran into 3 faulty voltage regulators new in the box. I replaced the VR with a 4th new one and now it charges fine. Does not over charge. James brought me over a different alternator but didn't need to install it. This is what I learned. Just because its new in the box doesn't mean it works. Thanks to all for your input.Comment
-
Re: Electrical problem
Mark - glad to hear you got it squared away and yes, that is unusual to run across '3' faulty but 'new' voltage regulators.
Were they purchased from a local auto parts place or mail ordered from a Corvette Parts Vendor? Just curious.Mike T. - Prescott AZ.Comment
-
Re: Electrical problem
Mark, got to watch out for those China made Reg. even if its in a Delco box it doesn't mean anything also the same goes with the Coil there all junk one of 50 may work stick to a NOS or a good use one that you know it works., DannyComment
-
Re: Electrical problem
Mark is it a 300 hp car?Comment
-
Re: Electrical problem
I keep a non points style VR (electronic style) in my tool box for testing purposes for exactly what you ran into.Comment
-
Re: Electrical problem
No, it is not a 300 car. Its a 365hp car.Comment
Comment