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Car won't start - relay problem?

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Very frustrating problem where the car won’t start via the key

parts replaced so far are ‘x relay’ (number 17) and ignition switch

obviously traced wiring back via red and black coded switch wire and can here relay switching but just no output to starter motor.

starter cranks first time linking direct onto it so can also rule that out.

Relay struggling  now and want to get up and running ASAP with this good weather lol


remember from a while ago a bloke rubjonny ??? Who was a MK1OC electrical guru?


any help appreciated.


Martyn 

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What year and model? Yes I just saw it is a 83 GX in your login name, but placing that in the Text of your message makes it easier on us old timers to see.

The X relay is the load reduction relay that takes HI-Load circuits as in Blower Motor, A/C /Headlights/Defroster/Wipers and temporarily disables them to allow full current to the Starter.

The Starter "Solenoid Pick" Runs from the Battery to the Fuse panel then Ignition switch, and out to the Starter.

You can add a Starter Relay to the Circuit, and then run wire from the Battery through the Relay then to the starter solenoid.  You use your existing Pick wire from the Ignition switch to power the relay.  (Ground for the relay is via a mounting screw).  Automatics had this issue and it was called a Heat Soak Relay as the starter would get toasty warm sitting under the exhaust manifold.

I have had ignition switches New out of the box be bad, and the problem is that in a 90 ish cabby over here with the Airbag makes then a PITA to change….

Make sure that your Solenoid Pick wire for the starter is on the right most spad connector of the solenoid.  Make sure that by removing the pick wire and using a meter, you have 12V to the end of the wire every time you cycle the key from off-to-on.  If you can't start the car you have to turn the Key to off, then back to start every time you try to engage the starter…

Grounds and Power Cables (Main) to the Starter from the batter should be clean and tight.  The Grounds for these little critters are Critical… IF you haven't replaced then yet, I would be thinking about this about now, as they run from the Battery to the Frame Horn, and then from the frame horn to the engine/tranny.  If yours is still oem, then it is probably an issue.  You can use two off the shelf cables from a parts store, and if you do that you can get a cable that has a couple of off shoot or connections so you can get some of the Grond rings off the screw.

I have found that over the years I can get the mind set that I have changed something so it is good…when in fact it was bad out of the box.

Also how old is your Battery and have you verified that your Battery is good, it could be that you have enough flash charge to get the starter to go one time, but it can't recover fast enough to give it a second spin.

Here is a how the "X" circuit works and how to diagnose it.  The "X" Circuit from the Ignition Switch. | VW Vortex - Volkswagen Forum

Also if you haven't had your starter tested, then you may want to remove it and take it to have it tested, as they have been known to get flaky.

For a quick Check of the condition of your Grounds, Take a Battery Jumper cable set and attach both end to the Ground post on the battery (NEG), then attach the other ends to a Lifting eye on the engine, and the Strut tower nut or other good ground point.

Let us know how it comes out.

Relay Struggling as in chattering when you crank the car is more of a Current issue on the battery, or a flaky Ground or power.
There isn't any water migration in to the Fuse panel is there?

And if the relay wasn't doing that before you changed out the ignition switch then you may have an issue with the switch still new parts are known to be bad out of the box.

Are you sure it isn't the Fuel pump relay that you are hearing?  They go out more often than the "X" relay… I mean that in the 15 years I have owned a 90ish cabby, I have never replaced one, as well as the 20 years that I drove my 81 Diesel Golf.

 

What do Divorces, Great Coffee, and Car Electrics all have in common?

They all start with GOOD Grounds.

Where are my DIY Links?
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