engine and drivetrain '72 Tii Electrical Issues

[Mitch_M]

Help me figure this out ladies and gentlemen: In the last week or so, I've noticed that my temp gauge has been reading high, and reading higher when the lights are on (it jumps up when I turn them on). I'm pretty sure the engine is not running hot because sometimes I'll be sitting at a light and it will read about halfway up the temp gauge in the dash, which is where it has always read, and then when I put it in gear it will jump up (not gradually like the engine is getting too hot on acceleration) and then jump from the halfway mark up to the red as I drive along.

 

This may be unrelated, but tonight I drove over to the gym and noticed the VDO voltage gauge in the center console was reading low. I turn the car off in the parking lot and try starting it again. Nothing. I figure well the wife will be off of work soon I'll get her to jump my car after I workout. Go workout for about an hour and a half. Car starts right up. I get home, turn it off, won't start back up. Anybody else experienced this?

 

The only thing I've done electric wise lately is get a new voltage regulator, because my voltage gauge kept jumping up into the 14+ volts range as I would drive along. Could the new VR be faulty? Sorry for the long post, but ya'll are always so helpful. TIA.

 

--Mitch

[OriginalOwner]

I'm thinking a grounding issue ..... on my '74tii there is a big brown ground wire in the area behind the alternator, and it is bolted directly to the engine block.  I had a couple of symptoms like yours.  I unbolted the wire, cleaned everything thoroughly, and rebolted.  No more problems.

 

Cheers,

 

Carl

[Mitch_M]

That's what I was thinking too after doing some searching on here. Thanks for the tip Carl. I'll give that a shot in the morning!

[conkitchen]

check your negative grounding wires at the alt to block and block to chassis, and baterry to chasis, plus the negative leads from the back of the cluster. Often times you mau need to wiggle them at the contact point to "clean" them and or tighten. Runnig extra ground straps never hurts too.

Reason it may not be starting when hot is due to heat sink resistance in the grounding wires.

Just go over all the leads from the battery out and inspect, tighten, replace.

Good luck and BTW 14 (13.8) volts at running is normal to charege the battery.

Also Esty might snap at you to do a search so do one next time. :-)

[ray_]

The VR is grounded through the fastening bolt. Clean that ground as well.

 

GL,

[PaulTWinterton]

Under the voltage regulator on the left front fender is a ground as well. It's fastened with sheet metal screw into the fender. Clean contact areas, and through-bolt for better ground and connection.

[Mitch_M]

Awesome. I'll check all those in the morning. Thanks so much everyone! And conkitchen - I'm fine with her snapping at me. I freaking suck at searching on here haha.

[Mike Self]

And one more thing to check...the negative ground strap and its two branches--especially the skinny cable that grounds the body.  If that isn't making good contact, the only ground path is via the accelerator linkage, a pretty tenuous path. It can also cause your temp and gas gauge needles to jump, plus other strange electrical occurrances.  The ground strap that leads to the engine generally stays pretty clean; it's the body strap that's usually the culprit.

 

mike

[saaron]

When I changed my VR, I got one that was plastic-bodied instead of metal-bodied.  That created many funky electrical issues.  I had to track down a proper metal one.  Installing that, along with cleaning the grounding point behind it, solved the funky problems.  

 

That said, my problems were a little different than yours...but they started with installing a new plastic-bodied VR.

 

Scott

[conkitchen]

So in summary I think we are all saying to check your ground wires. ;-)

[ray_]

So in summary I think we are all saying to check your ground wires. ;-)

 

It's a good tribute.

 

 

(apologies to the OP!)

[conkitchen]

We are now referring to it as faux

[ray_]

That's not faux!

 

I see only three in the pic!

 

[conkitchen]

More like a tre bute in that pic.

[Mitch_M]

Checked the alternator to engine ground. Cleaned it. Still having the hard start issue and it's getting worse. Where is the engine to chassis ground located so I can check it?

 

Edit: I also forgot to mention that my battery is in the trunk (done by the PO). Don't know if that makes a difference. Also, I hate electrical problems haha.

Edited September 15, 2014 by Mitch_M