76 Targa problems.

[Ciciro]

I have owned this car for many years and not to get into too much detail got the engine ripped off 7years ago at a shop that was to do work on it.Anyways I purchased another 2.7 L from a 77 from this site.It's now installed and a few other issues were dealt with to get the car running again.It has a rebuilt/reman starter a new battery and it has a new exhaust.Now here is my problem,it starts fine runs great,then out of the blue I'm taking my daughter to school and at the red light it dies,tach was bouncing all over the place car was running a bit rough and then stalls,turn the key and nothing,no cranking clicking or whurring.Turn the key off get my daughter into the drivers seat and push it around the corner.Now I go and boost it and it starts no problem and runs fine.I get it home and put it on the charger.Hope you're still reading sorry! A day later fires up up fine drive it for the next few days all during the daytime and no problems.Last night I drive it on a 20 min ride shut it down and 3hrs later I fire it up in the dark,runs great turn on the lights drive 2 mins up the road and it dies again same thing.Boost it this morning and drive it home.So I due some tests after i have charged it for like 4 hrs.I also cleaned the neg ground to the body and 14 pin connector after a few reads about this problem on another post..
Results
At Idle 12.6v
2400 rpm- 14.05v
lights on idle 12.09v
add radio-12.06v
add lighter plugged in GPS -12.05v
now I turn it off and 12.04v
everything is turned off with key on12.48v
Then I notice something is weird I turn on the running lights car off 12.6v
h/lights and fogs 11.98v here's the weird part the high beams are on with the fogs and the blue indicator is on in the dash.But this is in normal position.I try to get the high beams off and the dash indicator goes off but now so do the fogs.Isn't that backwards the fogs are supposed to go off with h/beams.almost done.Now is it possible the signal/headlight switch can cause this?If not where else do I look or test.Thanks for staying with it and reading!!

[Ciciro]

anyone with any suggestions?

[porwolf]

Hi Ciciro,

Not really being an expert in these affairs, it looks to me like you could have a bad battery or a charging problem. I think even at idle with headlights on the alternator plus regulator should keep the battery voltage at 13.8 Volts or slightly more. If at idle the battery voltage with lights on is only some 12 volts that seems to be too low. I have a similar problem with my 82'
Toyota Landcruiser in colder weather. I think in my case it is the diode regulator that in cold weather does not work correctly. I just watch it, and for longer colder temperatures I just recharge the battery if necessary.

[Ciciro]

is there any other tests I can do with a multi meter to check if its charging properly?

[Targalid]

The tach bouncing is a clue. It points to erratic voltage output. I cured the tach bouncing on my car by changing the voltage regulator which is mounted next to the CDI in the electrical box in the engine compartment a 35 year old unit from Marichal in France. You might check the connections at the VR since they are probably untouched in 35 years. You may see a change in charging performance simply by sanding the connections and reconnecting them. While changing the VR cured my errant charging problems and stabilized the tach somewhat, the final cure was replacing the original ignition wires with Magnecors from our host. The tach is now flat stable and no more dying engine. I found the cigarette lighter voltage meter from Vector quite helpful in diagnosing the problem: Amazon.com: vector voltmeter

[Ciciro]

now the voltage reading with the lights and a larger load on the system reads barely 12v is that normal or should it still be above 13.5v at 2500rpm?After testing it again today at 2500rpm I'm barely getting over 13v.Things keep pointing to my alternator,but I still am curious about my headlights.I'm thinking I wired the new h5's on with crossed wires.May have to double check that.I did it a long time ago but this is the first time I actually turned them on. I'll have to check the wiring dia.

[Ciciro]

Now after taking out the fresh air box I see a few wires not connected and a new red wire spliced into the fuse box and across to the glove box light.Now my mechanic disconnected this wire the other day and we didn't notice any issues.Now that I can see deeper it's more confusing.Looking deeper I see another spliced into a blue wire and connected to the clock and one side of the glove box light.I disconnect it from the light which works but not totally cause when you set it one way its on or the other its on.After looking I find the brown wire hook it up and now my light works totally.So off I go to see what else I find.I find a male connector just above the smugglers box not connected and still have no clue what it's to. Then I'm by the driver's side and see what appears to be a bl/gr wire so I hook up my test light and see,nothing!Turn on the ignition and I hear a switch and the test light blinking.So I turn the ignition off and turn on the hazard switch away she blinks and a bit brighter.Any Idea where it should go?Or does anyone have a simple wiring diagram for a 76.

[Ciciro]

Sorry also the wire that was to the fuse box went to a white block behind the clock connected to what appears to be the wiper motor. I also don't get a gen. light in my gauge anymore.What a nightmare this is.

[bassfishman]

Your alternator output is not enough to run the car and charge the battery.

My 76' Targa 2.7 output is 13.8 at idle. It drops to 13.5 with all lights on. At 3000 RPM I am over 14V. With the car off I am right at 12.5. If I turn the lights on without the car running it drops to 11.8.

[steely]

I agree with Targalid - search here for bouncing tach - think I read that it could implicate a faulty VR. I think you should be over 13.5 above 2000. You could try one of those cigarette lighter meters, but I don't know if you'd catch the spikes.

[Ciciro]

Thanks,I'm hoping its the regulator and not the alternator but time will tell.Thanks again all.

[peon77]

Your head light issue may be caused by the turn indicator/high beam switch, and unrelated to the charging issue.

[swiftdaddyo]

Make sure the fan belt is not slipping i.e. Loose, wrong size belt, oil on the pulley etc.

[Ciciro]

I was wondering if the headlight issue could be the signal /high beam switch. I need to get one first to test to see if that's the problem.Many issues but I need to take them one at a time.