electrical problems after paint

[rclayton12]

Hey guys, I had my 1973 240z repainted about a month ago, and I am having an electrical problem. It seems like there is some spot that is drawing current from the car on and off. When driving I can look at my ammeter and usually it is a little bit past half way, but now after paint, it is about 3/4 of the way to the right. Everynow and then, it will go back in the other direction about 1/8 of the way over to the left, it will cause my headlights to flicker dim. When that happens, everything seems to have power sucked from it, the blower motor slows down, and my lights will go dim. My question is there a place that i can check that maybe the guy at the body shop might have missed connecting a ground, or paint might not be giving it good contact? Thanks!

[xray]

Haven't experienced this problem myself, but have noted other folks who have electrical issues after paint seem to be attributed to painting over grounding points or similar type issues. Any belligerant overspray in the engine compartment? Check along the passenger firewall and frame rail and be sure the grounding ponts for the harness and negative battery cable look OK.

Of course, it may be coincidental (association with painting, I mean) and could be bad battery, battery/alternator connections, failing VR or failing alternator.

Good luck,

Steve

[rclayton12]

Is there a specific way to test the voltage regulator, i was suspicious that it may be malfuntioning?

[rclayton12]

Bought a replacement voltage regulator from Autozone for $30 and intalled it. It solved all of my problems.

[justaZcarguy]

Nice fix, and thanks for posting it.

Nothing like a faulty VR to come and go like a ghost...

Had that haunting already myself

~Brian

[Ramses]

I had the same thing happen to my '73. I replaced the vr as well and it fixed my problem, after I went through the entire grounding parts of the electrical system. I added 1 extra ground off the battery and one and replaced all of the connectors to the grounds.

[rclayton12]

ok now I have a new problem....Just before replacing the VR, my heater blower motor went out, the smell of burnt wires was lingering in the cabin of the car. Now i've checked every fuse, even the one that is behind the control pannel up on the transmission tunnel, and simply cannot figure out why the fan is not working. I do have the after market honda blower motor installed. Another thing that is strange is that the lights that illuminate the vent controls for the heater no longer work either, they went out with the heater... any ideas??

[Nissanman]

Well,you've let some smoke out and that is a no no:(

Couple of possibilities: -

a fried or broken a power wire,

a fried or broken blower motor

a fried or broken speed control resistor device

If the blower works on full speed but not at reduced speed, the speed control resistor or switch could be kaput.

You really need to do some voltage measuring on the relevant connectors to see when and if you lose the 12V supply.

[The blower fuse a likely suspect, check it again with a Ohm meter for continuity, or a voltmeter for 12V]

[Zs-ondabrain]

definately check the fuseholder for the fan. It's plastic and when it over heats, it loses contact with the fuse.

Use an ohms meter to make sure it has power going in and out of the fuse holder. And double check yer grounds.

let us know.

Dave.

[Nissanman]

A continuity check with an Ohm meter should ONLY be done on an unenergised circuit.

To check power you should use a Voltmeter.

Just trying to prevent a fried meter or confusing results:finger:

[rclayton12]

Success!! Finally got the heater fan working again. Turned out that there was two inline fuse holder underneath, one white and one black. I had just found the black one for the first time, and the end was melted off. Bought a replacement from radio shack and it solved the problem. Thanks for the help!!

[The Wingnut]

My blower motor is dead as well. Where exactly is this extra fuse holder? On the blower / heater core housing?