voltage problems

**Harmon C.** · August 16, 2003, 04:51 PM

Re: voltage problems

John At this point you need to buy some reading material. A 1973 service manual and a wiring diagram would answer many questions. Your headlight switch also switches the vacuum to raise the headlights and could leak or the hose may have came off. The regulator is inside the alternator and make sure the wires are hooked up right. Working on your Corvette will turn out better after reading the manuals. With the right tools you can fix your vette. Good luck Lyle

**john wensley** · August 16, 2003, 05:10 PM

Re: voltage problems

I couldn't agree more and I have already purchased a couple of manuals and they are quite helpful. But my question is could the voltage regulator shorting out couse the other problems or should I be looking some where else, and would a short couse the vacuum problem in the light switch. I have already checked the hoses and they seem to alright and are connected to the switch

**Harmon C.** · August 16, 2003, 06:30 PM

Re: voltage problems

John I don't think the vacuum problem was caused by the short as the hose just fell off or the switch is bad. Anytime you short things out anything can happen and I would make sure what you did to make it happen is hooked up right now and see what happens and then try to fix it.You may have fried some wires in the harness. Lyle

**Jack H.** · August 16, 2003, 07:06 PM

Re: voltage problems

HL switch has two separate stages: (1) vacuum to initiate the HL buckets to open/close, and (2) electrical switch the lights on/off. The ONLY thing these function have in common is they both actuate by the HL knob/rod. So, NO there is no interaction....

Frying wiring is NOT GOOD! The original insulation on the wires in the harness were a from of PCB that can/does BURN! The only alternative to a safer and more robust wiring harness is to purchase from M&H Fabricators who exclusively uses raw lead wire made from type GXL cross linked polyethylene. You can take a blowtorch (literally) to their reproduction harness's and all you'll get is localized melting--no open flame spreading through the harness!!!!!!!

As to the alternator, like Lyle said the v-reg function is a solid state module that's build inside. If you want to check/verify it, remove it from the car and take it to any local auto parts store that has a bench tester (most of the big places do these days). This will give you a go/no-go test but it's not an all encompassing test of the charging system generator under all conditions it has to survive and work within.

Last, bear in mind, there are a number of fusable links built into your wiring harness that are a 'last resort' safety feature. Some are visible and some are wrapped inside the wiring harness itself.

Most who aren't electrical techs or engineers use the term 'short' to indicate any/all failures in an electrical system. There are short circuits (will try to pass infinite current) and there are open circuits (won't pass any current). If you blew one or more of the car's fusible links during your 'episode' (Note: the Chassis Service Manual most always starts a given debug session with, Step 1: disconnect the battery) then you may well have open circuits (circuits that are plain dead--don't/won't fuction).

This is quite different from a short condition where you'll typically see smoke! So, the thing to do is either get, read and absorb, the technical literature or go find a compentent auto electric shop in your area and let the pros do the work for you in terms of fault isolation and repair.

**Jim T.** · August 16, 2003, 07:52 PM

Re: voltage problems

John you can test your voltage regulator on the car. If one of your manuals is a 73 Corvette service manual look in the alternator section and it should show you where to insert a screwdriver into the back of the alternator and test the voltage regulator. When doing this test solo you will need a voltmeter to measure the output or have someone watching the guage in the car for a charging indication. Also there may be a fusable link wire that comes from the alternator that could of burned into. My 70 has one. And then you have diodes in the alternator that could fail. Good luck.

**john wensley** · August 16, 2003, 10:01 PM

Re: voltage problems

thanks for the help I have ordered a new switch for the head light and I replaced the voltage regulator. I want to know if I cap off the vacuum lines to the headlight switch can I run the car until the switch gets in, all other problems have been fixed.

**Jim T.** · August 16, 2003, 10:43 PM

Re: voltage problems

Taking a shot in the dark here, if you pull down the control beneath the steering column will this turn off the vacuum to the headlight switch? It overrides the function of the headlight switch in keeping the headlights up? Of course if you want to drive the car with the headlights down the pull down switch has to be up, so would have to block off the vacuum hoses to the headlight switch. The headlights are easily raised and closed by hand if there is no vacuum being applied.

**Harmon C.** · August 17, 2003, 06:36 AM

Re: voltage problems

John You can drive your corvette just plug the lines or connect them with a tube. To make them go up or down use the overide switch. I never checked the headlight switch to see if the vacuum is open or closed to make the headlight doors stay closed. I'm glad you found the wiring problem and I would suggest you install a battery cut off and use it so you are sure of no problems when you are not near your Corvette. I use one on all old Corvettes. Lyle

**john wensley** · August 17, 2003, 08:56 AM

Re: voltage problems

Thankyou for all your help. It sure helped alot

voltage problems

voltage problems

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