Starter Motor Wiring Fault

[treesimon 0]

Hello everyone,

 

Im new to the forum so i hope i'am doing this right.

 

My problem is the intermittently none starting of my pug. Firstly i have read alot of posts concerning this problem and cant find the info that i need.

 

So far i have fitted a new engine wiring loom form a known good one and i checked it over very carefully.

Removed the brown multiplug that sits above the gearbox to take it out of the equation.

Fitted a second earth strap to the starter motor.

Tried 3 different Starter motors, large and the small version.

 

I have tested the voltage coming out of the ignition barrel ( the white multiplug that clips into the drivers side scuff pad) this is always 12.4volts with the key in the final position(start position) even when ive got it on hard fault.

 

I thought at one point it was the relay that had packed up in my toad alarm and had a new hornet alarm fitted. no joy still intermittently faulting. Had the alarm fitter take the starter out just to completely eliminate the possiblity of wire size causing resistance.

 

At one point i found wire 46 in the fuse box position D if i remember correctly, i cut into this and fitted a direct wire off of this to my starter motor. It never faulted once for over 6months. But! in doing this for 6 month my cold start would never shut of until the heat in the engine bay actually closed the bi metal strip (could take an hour or more) Definetly not a faulty SAD because put the wiring back to normal and it would work fine.

 

I know that in the engine loom wire 46 is joined by 2 other wires 1 being the sad from the ecu and another these then are crimped together then becoming 2. 1 for the starter and 1 for the SAD.

 

Does anyone know what i had done when i cut into the fusebox wire. Why the starter would fault and why the SAD wouldnt work.

 

Also people refer to piggy backing the starter motor cable from under the driver dash. From what part?

The white multiplug from the barrel? If so would this effect the SAD again?

my pug is a 1990 G reg phase 1.5 With the wiring back to normal, i use a length of wire when it faults now. Lol!

 

Any help would be appreciated as im out of ideas.

p.s i dont want to fit a relay or start button, Im trying to keep her standard.

[DamirGTI 344]

SAD is earthed via this the starter solenoid wire No. 46 hence non closing of the SAD when you add an piece of wire directly from the fuse box terminal to the starter solenoid .. though you can wire up SAD heating element separately if you wish , it's easy , anyhow heater element is really needed in order to fully close the SAD (as you've found out)

 

Perform continuity test with multimeter across this 46 solenoid wire , from the fuse box connector all the way till the end of the wire until you find where it's broken .. also check/clean up contacts inside the brown multi plug (i bet that theres your problem in the first place - oxidation ..)

 

Damir

Edited October 21, 2009 by DamirGTI

[treesimon 0]

SAD is earthed via this the starter solenoid wire No. 46 hence non closing of the SAD when you add an piece of wire directly from the fuse box terminal to the starter solenoid .. though you can wire up SAD heating element separately if you wish , it's easy , anyhow heater element is really needed in order to fully close the SAD (as you've found out)

 

Perform continuity test with multimeter across this 46 solenoid wire , from the fuse box connector all the way till the end of the wire until you find where it's broken .. also check/clean up contacts inside the brown multi plug (i bet that theres your problem in the first place - oxidation ..)

 

Damir

 

Do you mean the 9 pin brown multiplug located under the dash? as i would not have thought this would have oxidised being inside of the car. The 7 pin multiplug above the gearbox has already been remove.

 

also you are saying that wire 46 on the fuse board goes directly to the already referred to 9 pin brown multiplug and does not deviate?

 

Thanks

[DamirGTI 344]

On a Motronic car (without tachy fuel pump relay) this the solenoid wire No. 46 goes from the fuse box directly onto the starter motor solenoid but somewhere at the middle it connects with the SAD heater element earth wire No. 46a .. and that's it .. it does not go anywhere else as far as i'm aware .. and yes i meant the 7pin brown multi plug in the engine bay above the gearbox (if the multi plug itself was removed and wires re-soldered recheck the connection ..)

 

If it was Jetronic car then this solenoid wire No. 46 goes to the starter motor solenoid but it's also connected in line with the tachy (fuel pump) relay and ECU as well .

 

Damir

Edited October 21, 2009 by DamirGTI

[treesimon 0]

On a Motronic car (without tachy fuel pump relay) this the solenoid wire No. 46 goes from the fuse box directly onto the starter motor solenoid but somewhere at the middle it connects with the SAD heater element earth wire No. 46a .. and that's it .. it does not go anywhere else as far as i'm aware .. and yes i meant the 7pin brown multi plug in the engine bay above the gearbox (if the multi plug itself was removed and wires re-soldered recheck the connection ..)

 

If it was Jetronic car then this solenoid wire No. 46 goes to the starter motor solenoid but it's also connected in line with the tachy (fuel pump) relay and ECU as well .

 

Damir

 

My car is a jetronic. Do you know the location or route of this wire as the fuse box is a mess of wires and very hard to trace. Does anyone know where it originates from before the fuse board and where it goes after because it goes under the dash somewhere?

 

Will i need to strip it completely? Someone must have been here before?