Momentary loss
 

Hello, while driving my 1996 X-305 yesterday I pushed the button for the front window demister and I think coinsidentally the tach dropped to zero and the speedo the same.The dash lights all came on brightly for a second and the srs light on the dash came on and stayed on.Everything then back to normal with the srs light on. Baffled where should I start. I then parked and restarted everything back to normal and no srs light. The car has 156000 miles on it.It runs great with no issues since the ferrite disc was replaced.Can anyone point me in the right direction or has anyone had this issue before? Best Regards

One of the instrument cluster fuses is the # 5 / 10 amp on the LH heelboard fuse box

Power to this fuse is hot at all times from the battery and runs through the large 250 amp fuse link under the rear seat pan

This is different then the 2 heelboard fuse locations in front of the seat pan

See page 32 point 3 in the square box

The specific fuse is on page 33

http://www.jagrepair.com/images/Auto.../jagxj1996.pdf

The terminal nut on the fuse link can come loose and when you hit the front windshield heat it demanded too much current through the nut clamps dropping out your instruments

The at the battery fuse link can do the same and are easier to get to as a first try

The positive battery cable clamp can stretch over the years and a battery post shim available at the auto parts store can resolve this , 2 bucks with some dielectric between the cleaned battery post mating surface

Thanks I will switch them and keep you posted. Is the ignition switch pretty reliable on my vehicle?

I have been reading your other archives and it mentioned blue relays are not sealed well.I am going to replace all those. Are there any others I should replace? Do you recommend using dielectric grease? thanks

See edited post for correction

Dielectric grease is OK for power circuit applications like relays but not sensitive sensors

I would start with a simple battery test.
There are shed down relays in those series cars.
Is your battery new? Do you keep it on a charger?
Anything less then 11/12 volts, the car will do strange things.
If the battery is over 4 years, replace it with a acid standard battery, NOT AN OPTIMA, they do not hold up well.
Good luck.
Also ground and moisture issues but start with the battery.
GTJOEY1314
CLEAN THE GROUND CONNECTION AT THE BATTERY AS WELL.

OK will do checked bat v 11.77 v. cleaned terminals 850cca about 2 yrs old..thanks keep suggestions coming

A fully charged battery is 12.75 volts

https://cimg5.ibsrv.net/gimg/www.jag...64bb978095.jpg

Ok I will put charge on it and load test thanks for the information

Momentary loss
 

Hi ,I think you are right mine did the same. I was so surprised I did not think but you are probably right but it was so quick I did not notice any power loss. Thanks for the input

Momentary loss
 

OK the battery is ok load tested ...exchanged relays ....checked fusible link for tightness...ok cleaned grounds by battery and cleaned battery posts....Since this the first time it has happened I will post results in a week to see if it occurs again....Just a quick thought.I had to replace my ignition switch on my 1994 X-81 for an intermittent no start. It cured the problem. Is there a chance that the ignition switch is worn out? Just taking a wild guess. Thanks again and if anyone has had this happen to them feel free to include your thoughts.

PM me if you go there as there are some things with the switch circuit before changing the switch

The load tester to use is a heavy one and mot the small hand held unit , some still have one in the back room

https://cimg7.ibsrv.net/gimg/www.jag...ede3711ce6.jpg

OK ...this was the small hand held unit.I will try to see if I can get the heavy duty load tester.

Some of the local parts stores have them still and will test for you

An old timer independent shop will have the larger more realistic one as well