Land Rover Repair: 98 Disco computer problem?, windows radio, heat fan


Question
Thank you for your help.  Sometimes in hot weather (not severe heat, maybe 80 degrees) my '98 Disco will start but it makes a stange noise and nothing electrical-windows, radio-works.  Car will go into drive, but grinds if I shift back to park.  Problem corrects immediately if I turn car off and restart, so I assume I'm doing a computer reboot.  A related (?) problem is AC or heat fan when on high will cut off briefly when I am idling. Usually I turn off fan and turn back on which corrects it immediately. When this happens there is no change in tach or anything else I can see or feel. These problems are becoming more frequent.  Any ideas?
Thank you.

Answer
Hi Al,

regarding the hard starting during hot weather "strange noise and nothing electrical...", it could be the 'spider' - a multi-functioning immobiliser (part of the security).  There are sensors that monitor the temperature of the engine and fuel...maybe they are interferring with your electrics.  

The ideal solution would be to book your Disco with a LR mechanic on a very hot day.  This will ensure that the diagnostics would de done under the same conditions.  I think only a LR mechanic will find this type of problem.

As for the blower fan cutting out while being used on high, I've seen that problem with my '95 many times.  I think there must be a temperature sensor that cuts off the power to prevent overheating...otherwise, it could be a short that is triggered by the heat.  I've had this for years and it happens almost always on very hot days. So far, no major worries for me.  It would be major work to open up the dashboard and examine the blower motor and wiring harness.

If you see a change in your tachometer, its usually associated with your alternator.  The tach is measuring the alt rev's.  If there is no drop or spike when the blower fan cuts out...it almost confirms my theory that a switch of some sort is involved with the cut-out problem.

Have a dealer check out your Disco... that strange noise you mention is not normal.  Maybe its your alternator?

Best of luck,

JohnMc