Signs of a bad harness?

[tymarbry]

Hello All.

I am constantly worried that my car will catch on fire someday due to the harnesses Ive been hearing about, being old and overloaded.

I plan on rebuilding the harness to include relays but Im afraid I will mess things up badly.

My question though is,

Are premature headlight(s) failure a sign of a bad headlight harness?

I just bought New headlights (sylvania) for my 280z and I only got around to installing one so far.

The one I installed though has burned out already after like a week of use.

The headlight that I left in and didnt replace is now brighter and seems fine.

So whats going on here?

Thanks

[FastWoman]

I think the weak links in the headlights are the switches. Zs-Ondabrain (Dave) refurbishes them. He also makes some relay kits available through MSA.

Generally speaking, the harness wire should all be fine. There are a few trouble spots. For instance, if you trace out the heavy white and white/red supply wires, you'll find them factory spliced inside the wiring tree. Those splices can get corroded after a while. They're done with crimps and wrapped with electrical tape. The alternator output wire is also undersized for the later alternators.

Most of the electrical connectors in your engine compartment should be looking pretty crumbly and corroded by now, but those can mostly be replaced with new connectors from Ebay. Most are Bosch style 2-conductor connectors. Your throttle position sensor is a 3-wire Bosch and is available in wrecking yards off of more recent cars like Volvos. I don't know where you'd find another AFM connector, but that should be in much better condition anyway (less engine heat exposure).

All your other connectors should be pretty solid but could probably use a good cleaning/lubing. You might consider upgrading your fusible links to maxifuses, as those get pretty crumbly too.

[tymarbry]

Ohh yeah Ive got a handfull of "freebies" from the old boneyard in relays and such.

I did rebuild my healamp switch to get the corrosion off and they opperate as they should now. Really recomend rebuilding the switch also, very easy and fast, and fun.

But I forgot to mention that the dust/mud cover that goes inside the wheel well/inside the fender is taken out and I didnt place it back in because I thought it was useless.

could this be my problem? Could road dust and possibly rain watter have gotten into the headlight and fudged it up a bit?

[ktm]

The source for our connectors: Vintage Connections.

[SteveJ]

Hello All.

I am constantly worried that my car will catch on fire someday due to the harnesses Ive been hearing about, being old and overloaded.

I plan on rebuilding the harness to include relays but Im afraid I will mess things up badly.

My question though is,

Are premature headlight(s) failure a sign of a bad headlight harness?

I just bought New headlights (sylvania) for my 280z and I only got around to installing one so far.

The one I installed though has burned out already after like a week of use.

The headlight that I left in and didnt replace is now brighter and seems fine.

So whats going on here?

Thanks

Two causes that I'm aware of for premature failure are overvoltage and bad manufacturing.

The overvoltage condition is easy to check. Have someone start your car and operate the gas pedal. Check the voltage at the battery with a voltmeter and have your assistant take the car up to 2000 RPM. If you're reading much 15 volts (14.5 is preffered), the system voltage is going too high.

Now, this is where YOU SHOULD PUT THE YEAR OF YOUR CAR IN YOUR POST OR SIGNATURE. To diagnose an overvoltage, the year of your car is important to know. For instance, the 78 has an internally regulated alternator. If you put an interally regulated alternator in an earlier car, you can get an overvoltage.

Dave's standard relay harness is not designed for the 280Z. Contact him, and he might build one for your 280Z.

[esmit208]

TY

Also do you have a 40 amp or a 60 amp alternator? When you install components that draw more power the upgrade to the 60 amp alternator is suggested. Even todays car stereos can have issues if you don't upgrade the alternator. As well if you still have the old fuse box installed it would be a good idea to upgrade with a new one (no glass fuses) from MSA. In the unlikely event that you do damage the harness www.ezwire.com out of Ormond Beach Florida can build one to factory specs for less than $250. WHATEVER you do DO NOT splice anything into the main harness as this will cause a fire for sure. The car in my AVATAR suffered a BBQ one night as a result of splicing into the main harness.

[tymarbry]

Im sorry to hear that esmit208

My 280z is a 77' and I dont know of the alternator type.

I did buy some H4 housings as I am going the H4 or HID route now because I am tired of this problem already.

I guess I have a new question:

If I do upgrade my headlights to HID would I need to get the suggested harness to go with it, or will the lower power draw from the HIDs actually be better for a stock harness?

[SteveJ]

As well if you still have the old fuse box installed it would be a good idea to upgrade with a new one (no glass fuses) from MSA.

That wouldn't work, since MSA offers replacement fuse boxes for 240Zs. The OP has a 280Z.

In the unlikely event that you do damage the harness www.ezwire.com out of Ormond Beach Florida can build one to factory specs for less than $250.

The correct url is http://ezwiring.com/. I have to say that I'm somewhat skeptical that they could build a harness to factory specs for $250, though my definition of factory specs would be to match wire color/striping, gauge, length and connectors.

WHATEVER you do DO NOT splice anything into the main harness as this will cause a fire for sure. The car in my AVATAR suffered a BBQ one night as a result of splicing into the main harness.

Of course, that is true if you don't know what you're doing. I'm not trying to be mean. I'm just being honest. I spliced into my wiring harness 16 years ago and haven't had any problems as a result of my work. If you do it right, it's not a problem.

[SteveJ]

Im sorry to hear that esmit208

My 280z is a 77' and I dont know of the alternator type.

Run the test I described.

I did buy some H4 housings as I am going the H4 or HID route now because I am tired of this problem already.

I guess I have a new question:

If I do upgrade my headlights to HID would I need to get the suggested harness to go with it, or will the lower power draw from the HIDs actually be better for a stock harness?

Light output is VERY dependent upon voltage. Dropping from 12 VDC to 9 VDC will decrease light output by around 50%.

Relays and headlights have been beaten to death on here. Search and read up.

As for selecting headlights, contact H4Lights on this site. It's his business. He has evaluated many different products and is a treasure trove of knowledge on the subject. A cheap headlight conversion can cause a fire, too.

[tymarbry]

Thank you guys

I will run the Batt test tomorrow when im off and see what up. I know that the Voltmeter in the car reads like 16 I think when I drive which I think is broken but I dont know really until like you said, Test it out.

thanks again

[Zed Head]

The 1977 came stock with the external regulator. You could look at the spot where the external regulator should be to see if it's still there and plugged in, if you want to be sure of what charging system you have.

The voltmeter in the car is probably not correct. Mine was off by a couple of volts, read 16 instead of 14, until I adjusted it via the screws on the back of the meter.

Are you sure that the headlight actually burned out? Maybe you have a poor connection somewhere in the circuit (common problem). You can check the headlight with an ohm-meter to see if the filament is intact, or check the headlight circuit at the plug with a volt-meter (probably easier considering how hard it is to get the headlights out).

[Powderkeg]

Dave (Zs_ondabrain) built a headlight harness for my 76 280Z. You need to supple him with 2 or3 connections from a 280Z.

His harness works great!

Dave Ruiz