Engine Grounding Points (electrical gremlin)

TW,

Where are the spots that the motor (and electrical system) are grounded to the frame of the truck/truck body?

So far, in a brief search I've found the one by the battery tray (negative side). I am having an electrical gremlin and am thinking a ground wire is loose somewhere (that or I'm having the issue of a few others here on TW and have leaky fuel injectors - the issue is most pronounced after the engine is warm and is attempted to crank within a short (less than an hour) time frame).

When I go to start up I get nothing, dead motor. Turn off key, push in clutch a little deeper, try key again and sparks to life.

Recently I had the starter replaced, and I put in new spark plugs and wires about 1 month ago. Also I put in a new battery today to see if my issue was battery related (needed replaced anyways).

 

Off-hand I can tell you there should be a braided ground strap going from the back of the engine to the firewall.

 

That's a start, thank you. I plan to do a good look over tomorrow as well. It's the weirdest electrical gremlin. It's not consistent in its occurrence

 

It could be something as simple as a loose screw or bolt such as the ones that secure that braided strap for example. So check those too.

 

One on the firewall to the head/block I’ll have to look
From the battery to the block by the oil filter
From the battery to the fender

Add a ground from the block to the frame and you’ll be better off

 

does it have a clutch start cancel switch?

 

Sounds to me like the clutch safety switch is out of adjustment!!

Then maybe your just not pushing the pedal in far enough .

The switch needs to be closed for the engine to crank.


Leaky injectors most often causes a very long crank time before starting .

 

In my 2.7 engine it is on the back fat black wire between the engine and firewall. If the issue is not intermittent you can measure the voltage between the engine block and truck's body. This is the first thing I checked when diagnosing the issue with my temperature reading.



At first I was shocked to see any reading at all, but then I did the math. DC clamp meter showed 8.58A going between the engine and the body.



So the resistance is 0.02A / 8.58V = 0.0023 ohm. That is perfectly right.

 

this

next time it does not crank, instead of pushing the clutch deeper, just hit the button, and with your foot off the clutch see if it starts.

if it does, I would think its what others have already stated, the clutch cancel switch should be looked at.

 

It does have a clutch cancel switch...

 

Thanks! I had thought it may be a leaky injector scenario b/c I was having slower turnover when warm. Though, since yesterday, right before replacing the battery and afterwards, I'll have an on again/off again click and no firing/turnover when I go to turn the key. Power is still there (as in the lights on the dash light up in the ACC position). Then without a good indication as to why, and maybe 2, 3, or 1 try later it'll fire no problem.

So the clutch and clutch cancel could be out of adjustment, eh? I'll see if I can crank with that switch when this happens again (today I'm assuming).

 

This is very helpful. I'll have to get a meter. Just haven't pulled the trigger on buying one yet!

 

I Don't think the clutch cancel button can be out of alignment. but what it will do ( in my opinion ) is tell you if your clutch safety switch needs to be looked at since the clutch cancel button BYPASSES the clutch safety switch, and tells everything else its "OK" to start up without depressing the clutch.

please please please, make sure you are in neutral if you try using the clutch cancel button. We don't need your next update to be that you ran the truck into a wall trying this out

 

If you hold the key to start with the clutch out then while holding the key to start press the clutch in, if you hear the starter click then you know the clutch switch is working.

Your description makes it sound like a starter problem or possibly the wiring to the starter.

 

That's good to know! Thank you I actually haven't used it yet, so that is a BIG help. Also, makes sense that this is an easy test to see if the clutch safety switch is functioning properly.

 

This is true. I had thought that possibly the wiring was loose (hence why I thought initially a ground somewhere was loose since it was intermittent and not consistent). And the starter was just replaced a few weeks ago...it's possible the connections could have rattled loose. All things I'll check later today when I can get to diagnosing. Thank you for sharing

 

OK, the clutch cancel switch DOES work. Fires up no problem. I'm going to continue to observe the behavior of start-ups and also check the list of possible problem areas:

1) a loose grounding wire or wires
2) loose wires to the starter
3) clutch safety switch (highest probability?)

 

If the problem is related to the clutch switch there is a little rubber "cushion" on the clutch pedal arm that contacts the switch. It can get old and brittle and break apart. I just wanted to let you know if you are going to inspect that area.

 

That looks in good shape still. May have been replaced at some point since it is purply-blue and looks "fresh" still.

I'm going to go sleuthing for loose wires...though so far in experimenting with starting up (6 or so times now), I've had success each time I've tried...fired right up, no issues. Time will tell...

 

UPDATE:

Seems my power wire to the starter was loose, but not overly so. I couldn't loosen by hand, though when I put the 12mm socket on there I was able to tighten about a half turn or more total. That could be the gremlin and explain the click with dash lights and no start that occasionally occurred.

Will continue to monitor.

Thanks for the help all whom chimed in.