Mark R.

Now it's snowing..! LOL...
Snowing quite hard here, and sticking.
A few days ago, we had a big ice storm.
Truly weather roulette around here.
Probably see a rainbow later today...

Kevin in Atlanta

So, I got like 3 ohms with the injector harness connected to its ground point (VIII). I realized i did not connect the wounded wire to its ground point (IX)so I did and checked my readings again. Now the ohms are like 165! From reading other thread from Rich9928p I should be looking for a cut wire or a problem at MP VII. MP VII is the ground strap connection.

i. Power and Ground connections are key points to inspect and clean. The LH is grounded via Pin 17 to chassis ground point VIII. Use an Ohm meter to measure the resistance between LH connector Pin 17 and a chassis ground point. It should read as close to zero as possible. If it reads a high resistance, a corroded ground connection at MP VII or cut in the wire could be the problem.

Kevin in Atlanta

Checked the ground strap and it registers 0 ohms. I think there is a broken or cut wire, I guess.

the flyin' scotsman

how did you check it?............end to end the strap should read zero ohms.

Kevin in Atlanta

I tested it from the end at the wing bolt to the battery clamp.

Kevin in Atlanta

According to this picture the 'hook end' of the connector should be next to pin 1. On the connector on my 88 the 'hook end' of the connector is near pin 18.

I looked at the 90 GT in my garage and it too had the same orientation.

I confirmed constant 12 volts at pin 4 and near 0.3 ohms at pin 17. That would indicate the grounds are fine and 12 volts is being provided.

I can't reconcile the difference in the connector styles. I got that picture from a thread about '88 pinouts I think was provided by Andrew.

Or should I just ignore that and carry on?

Rob Edwards

I have never understood the orientation of that diagram- perhaps these real photos are clearer, they're both from a '91 harness:

LH:





EZK:

Kevin in Atlanta

Nice pictures.

So, if my connectors look like your connectors does that mean my harness is not a 88? Was there year they changed over?

John Speake

This picture from the WSM should answer your question:-

Landseer

The grounds can test with no resistance with a meter, but have insufficient capacity to sustain the volume of current, ie, number of electrons, to operate the car. On top of that, a ground failure can appear random because presumably humidity or mechanical disturbance will make the passing of sufficient current variable. It is very misleading when narrowing issues. That's why we clean all the grounds, polish and re-fuse the CE panel, and replace the ground strap on these old things before even trying to start them.

dr bob

Kevin-

Just a reminder that Ohm readings need to be taken with the battery disconnected, particularly when checking grounds and primary wiring. A wire with resistance will have a voltage drop through it when any current is flowing. Amazingly, Ohm meters pass a small current through the part or connection you are testing, and that can easily mess up your readings if there's more than zero Ohms.

Hope this helps!

Kevin in Atlanta

Wow - I did not know that - and it confirms my lack of knowledge. Thanks!

I rechecked my readings with the battery disconnected. 0.00 ohms at pins 17 and 5.

Pin 6 to chassis I get no reading at all. Above it says I am supposed to get less than .50 ohms

the flyin' scotsman

I believe that's for pin 5.

Pin 6 should read zero ohms

Kevin in Atlanta

OK, I misunderstood the arrows above I guess.

I am going to press on with the IX ground wire repair and put it back together for additional testing.

the flyin' scotsman

an easy check to ensure your meter is functioning correctly is set the selector to resistance/ohms and touch the negative and positive leads together..........the meter should read zero and depending on model may also beep.

Separating the leads should give a max reading or no readout on the meter.