Jump to content

Bodged wireing now car won’t start


Keith Cooper

Recommended Posts

Another thought you could try is whilst turning over the engine have somebody spray some easystart into the throttle body, if it tries to fire/run then you know you have spark & it's just fuel you're lacking. You could also take out a plug to check obviously, but I'm lazy

Link to comment
Share on other sites

  • Replies 31
  • Created
  • Last Reply

Top Posters In This Topic

50 minutes ago, Longboarder said:

A what's it for question. The connection from coil negative to 18 on the instruments? Who puts anything other than a switching wire on a coil negative?? Can you take it off the coil neg and do something else with the wire from18 on the dash?

This is an interesting point.   I initially assumed it was something to do with the rev counter, but when I got a spare instrument cluster I drew up a diagram for the printed circuit board on the back.   At first check that pin does not appear to be connected to anything on the cluster.   That doesn't make much sense (although this a Robin Hood we are talking about 😀).    I didn't follow it up (if it ain't broke don't fix it), maybe I should.

Because the Fuel pump doesn't run when the ignition is switched on I still think the problem lies with either the Fuel Relay (I had one fail on me), or the ECU Relay.    As I said before, if you can hear the stepper motor operating and the ECU relay switching off 10 seconds after the ignition is switched off then the problem is the Fuel Relay If not then it is the ECU relay.  And swapping each one with the Horn Relay (which is what I did), will solve the problem.

Link to comment
Share on other sites

Red herring. Probably to the rev counter as you say.

Another thought. Do you get warning lights on the dash? All there? Oil light goes out when cranking? Rev counter registers?

Disconnect 18 anyway in case its blown through to earth via the rev counter. (Thinking: when you wrong plugged it something in the dash got 12V it wasn't expecting or able to cope with. Hence the spark.)

Did you wrong plug when the ignition was on ( If so the spark might be unimportant or very important.) or did you get a spark when you switched ignition on after (in which case the spark is vital)?

Link to comment
Share on other sites

Cable in the post.  Once installed you will be able to test the 2 relays using software.   Not sure if you know already but the data port is a floating 3-pin plug near the ECU with a rubber cap.

Edited by alanrichey
Spelling !!
Link to comment
Share on other sites

Hi guys, I definitely have no spark, I have taken out the plug and checked, also I have no power going to the coil, I have put a multimeter on it and it has no power, there is a fuse below the coil and I have checked that but there is no power going to the fuse.. this is a bright green wire that appears to be going to the ECU.... it’s gets very difficult to see because it then goes behind the dash and visibility is very poor..., I may have to take out the dash.... 

all the indicators and lights work.... but I have no ignition lights at all.... the car does turn over just doesn’t start 

I'm convinced there is either a fuse I can’t find or the ECU has gone.... I have a friend popping over tonight who is a lorry mechanic so another pair of eyes may help

What is strange is when the multi-plug came out of the back of the clocks, the car would not start, when I pushed it back the car started and this happened a few times, I was going to work out a more secure way of fixing them in when I put them in upside down and got the spark.... it doesn’t spark anymore which is why I think something has blown...

Very confusing 

 

 

Link to comment
Share on other sites

Hi guys.... I think I have made some progress:

i ran a live wire directly from the battery to the live side of the coil and he presto I suddenly heard the whirring noise from the fuel pump... so I held the wire on the positive side and got my wife to start the car.... and believe it or not it started up perfectly ....

when she turned off the ignition the car continued to run until I disconnected the live I had put on the coil .... is it possible that somehow the ignition live on this car has been wired through the dash ?, very strange but at least I am getting somewhere .... 

any thoughts ???

Regard Keith 

Link to comment
Share on other sites

I did a search for the Escort Mk7 instrument cluster and it suggested that Pin 18 is an ignition switched live (output).    So I guess that makes sense if that is the primary source of power to the coil.  It also explains why I couldn't find it linking to anything as it probably connects internally to the 12V ignition input to the cluster.   You have probably burnt out part of the circuit board.   You just have to find the gap and solder a jump wire.

Or, if you can't find what has burned out all you need is an alternative source of ignition-switched live and join that to the coil.

Edited by alanrichey
Link to comment
Share on other sites

Hi Alan, yes I think that makes sense, I think I will be better off wireing a new wire from the ignition to the coil via a new relay, that way the dash clocks will have no effect on my wireing.

i have found a replacement set of clocks from eBay for £18, so I have ordered it to see if that makes a difference, I’ll let you know how I get on

I'm certainly learning a lot more about the Robin Hood a bit more quickly than I had planned :) 

 

best Regards  

keith way 

Link to comment
Share on other sites

Looking at your wiring diagram, no power to the coil also means no power to pin 2 on your ECU and no power to pin 20 on your dash as both those are fed from the coil positive. So you have a break between battery pos terminal and the coil positive terminal.

Prove the segments of this circuit a bit at a time.

Is there continuity between batt pos term and ign switch pin 1. Looking for wire failure or blown fuse between these points.

Is there continuity through the ignition switch to pin 4 when the key is turned on. (Could be a failure of the ignition switch).

Is there continuity from ign switch pin4 to coil pos. This last only if the wire goes direct from pin 4 to coil pos. Sometimes a builder and most manufacturers put a whopping (say 80amp) relay in, operated by the output of pin 4 to supply all the ignition live circuits (which would include dash, coil, ECU, wipers, heater,etc) so the green wire to the coil may not come direct from pin4 but may instead come from pin 87 on a hidden heavyweight relay.

Link to comment
Share on other sites

Hi guys,   Eureka ..... the 2nd hand clocks I ordered from eBay arrived so I took out the clocks ( which was a 2 hour nightmare) and swapped them over and the car started straight away...... I looked at the clocks in more detail and sure enough you can see where the circuit board behind has burnt out.... I have attached a picture (the break is next to the ford sticker).

thankfully I was able to swap over all the clocks from the broken circuit board set and put them in the one that works so I have my original mileage back :)...

thanks for all you support guys it was quite a few stressful days trying to work this out but at least I have learnt a lot of things about my car.... also the coil and fuel pump getting its power from my clocks..... who knew !!!!!

i just need to secure the multi plugs in the back of the clocks a bit better than the person that installed them previously 

I also modified the clutch at the pedal end as per your suggestions and I have changed the short clutch cable that someone put in the car and the clutch is 100 times better.... :)    so getting there :) 

9DC90DAC-2EC3-4BE6-9EDD-0FA758D0EDD9.jpeg

BF84B0EB-E8C3-4527-ACBD-D3ADC53F9983.jpeg

F7A45649-060E-4217-9D22-0CE8D39B4A68.jpeg

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
  • Recently Browsing   0 members

    • No registered users viewing this page.

×
×
  • Create New...