Electrical Issues

patrickt · #1 (**permalink**) 09-06-2011, 10:59 AM

Quote:

Originally Posted by HighPlainsDrifter

Hi,
Take the alt off and file or sandpaper the places where the bolts go through to hold it to the head, your BAD GROUND is there.
Perry.

The ERA wiring harness has a black wire that runs the ground to the alternator -- but it never hurts to check all the ALT connections (which he'll certainly do if he removes the alternator).

HighPlainsDrifter · #2 (**permalink**) 09-06-2011, 11:13 AM

Hi,
The alt puts out alot af amperage and needs a #8 pos and #8 grd wire. I find that more amperage is blocked by a high resistance grnd at the mounting bolts. Also with a chrome alt you need to grind or file the chrome off so there is a good ground at the mounting bolts.
The fans need a relay to isolate them from the alt and ignition or they can back feed a voltage spike and blow the ign. On MSD igition you need a relay on the main power or the engine can run on from backfed voltage from the alt or fans, NHRA tech will check that the engine does not run on.
Perry.

TKlauber · #3 (**permalink**) 09-06-2011, 07:14 PM

Thanks for the extra advice Perry. Nice looking Daytona BTW. I think ERA scrapped their plans to build their version of the Daytona. To earlier posts it seems I am confusing ammeter and voltmeter. I guess a voltmeter would read 12 volts at idle and ammeter zero assuming nothing major drawing the current.
I am busy this week with work so it will be this weekend before I can get to the car. Gotta work to pay for these toys! Tom

Blas · #4 (**permalink**) 09-06-2011, 07:55 PM

Unplug both headlights. Try to replicate the problem. If nothing, plug in one headlight, repeat test, if nothing, unplug the 1st headlight and plug in the second, test again...now you have some idea of where to start looking..

patrickt · #5 (**permalink**) 09-07-2011, 04:20 AM

Quote:

Originally Posted by TKlauber

I guess a voltmeter would read 12 volts at idle and ammeter zero assuming nothing major drawing the current.

Tom, when the car is not running you will see about 12.6 volts on your volt-ohm meter (VOM). When the car is running you should see 1.5-2.0 volts higher, say around 14.3 volts, or the like -- but not 15 volts, that's too high.

PDUB · #6 (**permalink**) 09-08-2011, 12:14 AM

Quote:

Originally Posted by patrickt

you will see about 12.6 volts on your volt-ohm meter (VOM).

I, too, thought that the M in VOM was meter, until someone explained that it was actually "Volt-Ohm-Milliampere..."

But it took years for me to remember it

! Now with the digital meters available it's easier to remember DMM for digital multi-meter...

You're (we're) showing our age here Patrick

.

TKlauber · #7 (**permalink**) 09-10-2011, 02:17 PM

Well I finally got off my duff and got my hands dirty with this. I took the alternator off last night and took it into NAPA for a test. Kelly the guy that works there is an old friend (he is into Model A Fords BTW). The alternator tested bad. I could not believe it. It looked in mint shape. So I bought a rebuilt one and kept my core. $40 bucks. What a great price. Put it on and of course it seems to be working fine. I checked continuity of the wires to the alternator and they were fine. I dug into the horns as there seemed to be an intermittent loss of horn and found a bad ground at the harness at the driver front. It is at the left horn harness. Actually I should have filed off some of the powdercoat there when I put it together 15 years ago. I also found that one of the horns doesn't work and probably never did. I tried a direct wire to it and never could get it to sound. I did not mess with the tuning screw which looked like it was in proper place. Replace the horn some day. Now the lights. I checked fuses - OK. I noticed I could get the instrument lights to work some of the time but not the headlites. I noticed the reostat for instrument lights and turned it a couple times and the instrument lights would come on and off so I think the reostat has some minor corrosion internally. I worked it some and finally all the lights would come on. It is cheap but period correct. It probably needs to be used a little more. Plus Marion SC is in a swamp - Swamp Fox City is our motto so damp is ever present - another excuse to get out and drive. I cranked it up and it cranked fine. It idles a little rough like a plug or wire is off so I will check that. Who knows how long I have been running on battery? I have never tuned the car - do you tune an electronic ignition? I know how to tune a points ignition but not this newer stuff. I will figure it out. Maybe advance or retard the spark some till it sounds right. I have a nice SUN timing light. I did replace the plug wires with some from NAPA. They are 7mm and should be 9mm so they gotta go. Maybe put them on the boat. They don't even fit in the looms. Thanks for the help fellas. Seems everyone had something to offer on this. Tom

patrickt · #8 (**permalink**) 09-10-2011, 03:20 PM

Quote:

Originally Posted by TKlauber

I have never tuned the car - do you tune an electronic ignition? I know how to tune a points ignition but not this newer stuff. I will figure it out.

Tom, if you have an electronic ignition and a hydraulic cam, your tune-ups are pretty much limited to replacing your spark plugs, adjusting your timing, and cleaning/adjusting your carb. That last item more than anything. I have a friend who recently had some Holley carb trouble and took it apart for a thorough cleaning. Inside the bowls, the gas literally "sparkled" with what looked like glitter from a little girl's craft kit. The ethanol was slowly eating the coating away and, of course, causing havoc with all the carb's circuits. And teeny-weeny clogs do act differently as the carb heats up and as vacuum values change (from another thread).