5 GT Turbo 5 gt turbo electrical issue's

[clarky_gtt]

I'm having a nightmare with a number of peculiar electrical problems.

I can't get my oil level and pressure gauge to work. Keeping in mind I have fit a new engine loom, new genuine level sensor and new genuine pressure sensor.

I also don't have the oil pressure light, handbrake light, water temp light or the oil pressure dial part on start up.

I have tried 4 different speedos, all known to work and the same issues.

I have 12v to the speedo, 2.3v at the oil gauge plug on the speedo, 2.3v at the level sensor plug

Also, the left hand indicator bulb on the speedo stays illuminated when the lights are switched on. I've cleaned the rear earth under the light and the a pillar earth many times, no change.

I'm no auto sparky, but there's power where there needs to be power. I've tried all the usual fixes and still all of the above!

Any advice a help? Please dumb it down haha

 

[Brigsy]

I had the no warning light issue years ago on my old white gtt. I believe the issue was down to earthing on the engine loom. Maybe give the connector of doom a wiggle under the bonnet.

 

[Brigsy]

Also are all earths intact on the dash harness? From memory they are both sides in footwell.

 

[Big Steve - Raider]

First thing would be to short the connections to the oil level sensor, and see if that moves the dash needle.. if not, it will probably be the needle at fault..

 

[clarky_gtt]

Also are all earths intact on the dash harness? From memory they are both sides in footwell.

I thought it was just the passenger inner a pillar that has the earth's? I've cleaned these up and no difference

First thing would be to short the connections to the oil level sensor, and see if that moves the dash needle.. if not, it will probably be the needle at fault..

I tried that with the level sensor, absolutely no movement. But, I took one working speedo, shoved it in my phase 1 and everything works, then straight into my phase 2 and nothing!

 

[clarky_gtt]

I had the no warning light issue years ago on my old white gtt. I believe the issue was down to earthing on the engine loom. Maybe give the connector of doom a wiggle under the bonnet.

I've wiggled, cleaned, un plugged and plugged the doom plug in many times. No change

It's got me stumped and doing my head in!

 

[clarky_gtt]

I noticed today with the engine running the oil warning light is on. I have no idea if I should be concerned or if its just another electrical issue. You can also see the gauge is slightly illuminated like it does on start up.


And still no oil gauge!

 

[Will D93]

i think there is an earth on both sides of the dash, I think earthing sounds like your issue.

the oil temp and level gauges will have 12v feeds, earths and a signal wire

handbrake/level is just 12v into the clocks, through the bulb, and if either the hand brake or the reservoir switch ground the light comes on.

oil pressure switch is grounded with engine off, so when clocks get 12v (ignition) the light comes on. When you’ve got pressure the sensor (switchopens and the light goes out.

Oil light staying on while running, and indicator staying on suggests to me you probs have a mix up of earths and power.
probs just one mistake

a multimeter, basic as you like, 2 functions, voltage reading, and continuity. Should be able to work through it and see what is working properly and what’s getting confused and why.

continuity through a wire in itself,
And continuity between something and earth

Helping with wiring over the internet is a nightmare, I hope some of that makes sense and doesn’t confuse things further

 

[clarky_gtt]

Thanks Will,

i thought the sender wires maybe back to front, So i checked my original loom and sensor, nope, they are correct! Orange wire, large connector, brown wire small connector

i flipped them around and ran the car anyway, only change was no oil light or gauge light. Still no life in the oil gauge

so i'm still at square one!

 

[Brigsy]

Check the engine earths are decent, especially the engine loom to the front of the block. Jump lead on the block to neg to test.

 

[clarky_gtt]

i have painted the block and zinc plated that front earth bracket, so possibly.
I probed the positive of the battery to earth at front of the block, shows 12.5v. I'll try the jump lead tonight

 

[clarky_gtt]

a few people say there are earths on both sides of the dash, is that true?

i was sure it's just the passengers side?

 

[DaveL485]

a few people say there are earths on both sides of the dash, is that true?

i was sure it's just the passengers side?

There are usually earths to the looms on both sides, my 9 defo does have.

 

[clarky_gtt]

again, conflicting stories of there being none

and i looked last night. i couldn't see any

 

[Norwich Nick]

 

[MOS]

Looking forward to your findings! I also have issues with the oil gauge, and I also fitted a new loom recently.. Sometimes I can get it to work when I switch the wires around on the sender unit, then next time I turn on the egnition it it works no more.. I've come to suspect the ignition barrel or a relay somewhere, but haven't looked too much at it yet.

 

[clarky_gtt]

I have another dash loom in my attic, I'm going to look for a drivers side earth.

I searched on a gtt Facebook group, everyone confirmed it's passengers only though???

 

[Will D93]

Too many conflicting opinions. Some may have had 2, some maybe not. Difference between ph1 and 2 maybe?

best to look at your own and check it out

 

[clarky_gtt]

my auto sparky friend spent a couple of hours on the car with me yesterday evening. His prognosis is my new oil sender is faulty!

i'm going to try my original one that i had plated this evening and see if any change