engine and drivetrain '72 Tii Electrical Issues

[peterschop]

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.

 

That is the same question that I asked. As it turns out, I had no engine to chassis ground. I attached a 10 ga wire from where the coil mounts to an engine bolt. It took care of my jumpy temp gauge and fixed my tachometer that never worked above 4K and bounced all over the place. Now it is rock solid all the way up!

 

Make sure that the battery in the trunk had a cable going from the neg post to the body, same as if it were in the front.

[conkitchen]

Since battery is in trunk: You may have 1) too thin of a + cable wire to the starter 2) a poor ground connection at the battery (trunk) location. Back out your connections from the starter and verify.

once you move a battery to the trunk the current resistance increases due to the length of travel.

But what do I know.

[Mitch_M]

That is the same question that I asked. As it turns out, I had no engine to chassis ground. I attached a 10 ga wire from where the coil mounts to an engine bolt. It took care of my jumpy temp gauge and fixed my tachometer that never worked above 4K and bounced all over the place. Now it is rock solid all the way up!

 

Make sure that the battery in the trunk had a cable going from the neg post to the body, same as if it were in the front.

Peterschop: Do you have a photo you could post for a reference? That may be my problem as well.

[peterschop]

Simple fix but it worked wonders. One end of the ground wire is attached where the coil mounts and the other end to an intake manifold bolt. I tucked the wire behind the distributor. 

 

Edited September 15, 2014 by peterschop

[Mitch_M]

Simple fix but it worked wonders. One end of the ground wire is attached where the coil mounts and the other end to an intake manifold bolt. I tucked the wire behind the distributor. 

 

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Thanks for posting that Peterschop. I'll try that out tonight/tomorrow morning and see what happens.

[Mitch_M]

UPDATE: I took my alternator to engine ground wire off. It partially broken so I replaced it with a new 10 ga. wire. Seems to be starting and charging better now. The temp gauge is still jumping around when I shift gears and then steady when I'm in gear. I'll check that ground when I have time to pull the cluster and report back. Thanks for all the help everyone!

[peterschop]

When I bought my car it had no alternator to block wire and it did not charge. Added the wire and that solved the charging problem. Then I added block to chassis wire and it took care of jumpy gauges. I would recommend that ground also.

Edited September 16, 2014 by peterschop

[Mitch_M]

I've got the block to chassis wire, and it looks like a battery wire (very thick). It looked like it was in good shape, but I may take it off and try a new one to see if that solves my jumpy gauges. On another note, when I went to start it after it had sat for a little over an hour, I had to push the gas pedal to the floor for it to start. I didn't even get a crank until I did that (like the battery was dead, but it's not). Would that be an electrical issue? To me it sounds like it's a fuel delivery issue (cold start valve not opening?). Thoughts?

['76mintgrün'02]

Not cranking until the pedal is depressed would not be a fuel issue, but still an electrical one.  That symptom suggests Mike's description in post #8 in this thread.  I would definitely remove, inspect, clean and reattach the ground strap/cable/wire.

 

 

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.

 

[ray_]

Also, read everything here: http://tiiregister.com/

 

Darn, seems he lost the domain. Try here: http://web.archive.org/web/20140105192729/http://tiiregister.com/

Edited September 16, 2014 by ray_

[Mitch_M]

Mintgrun - My battery has been reloated to the trunk, so I don't have that branched ground strap. I'll take the chassis to block ground off tonight and make sure it's cleaned well.

 

Ray - I was actually just looking at the register to help with this. Thanks for the link!

 

Edit: As much as I hate electrical troubleshooting, it's a relief to me that this is electrical and not fuel related. I don't want that Kfisch going bad!

Edited September 16, 2014 by Mitch_M

[nutbehindthewheel]

Here is how car grounds:

Alt grounds to motor via small (brown) wire

Battery grounds to motor via negative cable attached to block

Negative cable also grounds to chassis via ground strap

You need all 3 grounds attached regardless of where battery is

I believe if alt ground no good, only results in non- charging of battery,

otherwise everything ok until battery doesn't have enough juice for starting

[Mitch_M]

So Nut: how would you suggest I ground the batter to the motor? Just a long ground cable?

[peterschop]

So Nut: how would you suggest I ground the batter to the motor? Just a long ground cable?

 

I would make sure you have neg to chassis in the back and chassis to block in front as well as alternator to block.

[conkitchen]

Since we are all throwing our hats in the ring: Point of clarification on a bad Alt ground wire; the only result of not charging may be true as well as it will internally burn out the Alt. That is all.

Edited September 17, 2014 by conkitchen