Restoration-Mini

Technical Forums => Maintenance and Modifications => Topic started by: dutchy1978 on March 21, 2011, 05:20:18 AM

Title: Dash cluster electrical problem.
Post by: dutchy1978 on March 21, 2011, 05:20:18 AM
Hi all,
I installed the wood grain dash from my 1994 half cut mini into my 1988 mini today and found that the engine would not turn off when I turn the key off. If I take the big plug out of the cluster the engine will turn on and off with the key like it should but not with the plug in.


Things that I have worked out so far are:

I pulled out the bulb for the battery light and it didn't fix the problem. thought there might be feed back from the alternator.
When I turn off the key the engine still runs and the orange oil light stays on until I disconnect the plug from the back of the cluster.
I checked the Diode and it is there so I guess it is OK. I even tried my old 3 dial carb cluster and it too had the same problem so I am guessing it is not the cluster that is the problem although it must be something to do with its wiring.


The following voltage is what I have measured at the cluster plug while plugged in.

When the ignition is on and the car is running:
White ignition wire is 12V
Brown/Yellow wire is 12V at cluster plug. 15V at the alternator plug (after diode)
White/brown wire is 12V (goes to the engine management relay)

When the ignition is off all of the above applies till the engine stops after about 20-30 seconds. slowly dies.
once the engine is off:
White ignition wire is 5V
Brown/Yellow wire is 5V at cluster plug. 0.7V at the alternator plug (after diode)
White/brown wire is 5V (goes to the engine management relay)

It seems as though the plug to the cluster still has some sort of power even when the ignition is turned off.

Once the plug is removed the voltage reads:
White ignition wire is 12V
Brown/Yellow wire is 50V (fluctuates from 5-50V) at cluster plug. 0.7V at the alternator plug (after diode)
White/brown wire is 5V (goes to the engine management relay)

Hope i haven't scared everyone off with this.

The good news it that the engine does eventually die after 20 or so seconds but as mentioned, the oil light never turns off.

Any help will be appreciated.
Title: Re: Dash cluster electrical problem.
Post by: Willie_B on March 23, 2011, 03:56:08 PM
Sounds like you still have power to the coil. For the engine to continue to run there needs to be power to the coil from somewhere.  I would start by tracing any wiring for a tach if you have one.
Title: Re: Dash cluster electrical problem.
Post by: dutchy1978 on March 23, 2011, 05:02:39 PM
Cool thanks. the Tacho has a seperate wire to the dash and is not part of the plug for the rest fo the dash cluster. I will check the wiring to the coil tonight for traces of power when the key is off.

i have done some many tests over the past few days that I have forgotten what results appeared for each test. With the key on, with it off,cluster plug in, cluster plug out etc. just over it now.
Title: Re: Dash cluster electrical problem.
Post by: macmanron on March 23, 2011, 05:21:45 PM
Willie-B  did I sell you that crazy dash out of the woody wagon?? I had to delete my other email account and I lost your/his email?
Title: Re: Dash cluster electrical problem.
Post by: dutchy1978 on March 23, 2011, 05:26:02 PM
Just in case you are thinking it is the dash, I actually put my old dash in which is a 3 dial dash too and it made no difference. I figured it is no the dash that is the issue but more the wiring feeding back to the dash.
Title: Re: Dash cluster electrical problem.
Post by: London Dry on March 23, 2011, 09:46:20 PM
Did you ever have the engine & dash running while it was parked on the 1/2 Mini? With my SPI, I was warned that the ECU can be squirrely.

Two sites I troll for advice are:

http://www.minimania.com/msgthreads.cfm (http://www.minimania.com/msgthreads.cfm)

http://www.theminiforum.co.uk/forums/index.php? (http://www.theminiforum.co.uk/forums/index.php?)
Title: Re: Dash cluster electrical problem.
Post by: dutchy1978 on March 23, 2011, 10:57:09 PM
YEH, it was all running when i bought the half mini. i made sure of that.

back to basics tonight. check every accessory that i have added to eliminate bad wiring on my behalf.
Title: Re: Dash cluster electrical problem.
Post by: dutchy1978 on March 25, 2011, 04:02:47 AM
Woo hoo. All sorted.

When I pulled the wiring harness off the half mini, I marked every plug. Unfortunately the oil pressure switch was broken and was only showing the bolt and no pin. So I thought it was just a plug in the engine block. The Connector for the oil switch was grouped with the 3 coil wires so I attached it to the coil cos the coil had 4 pins. Hence the back feed when the dash was plugged in.  :-[

Any way, disconnected the oil switch connector from the coil and all fixed. Engine turns off with the key.
Tomorrow I will take the oil pressure switch out of my 998 and put it in my SPI then connect the wire to it so the oil light works.

Live and learn I suppose.

Title: Re: Dash cluster electrical problem.
Post by: Willie_B on March 25, 2011, 04:12:35 AM
That was the extra power to the coil. Good job figuring that one out.  4.gif
Title: Re: Dash cluster electrical problem.
Post by: 94touring on March 25, 2011, 08:14:23 AM
Yeah good job, I'm horrible with wires.