Tack acting funnie!

[jusjay]

Hey, anyone come across this in the past? My tack does not work until I drive about 10 miles then seems fine? The rest of the it seems to be ok but if the car sits for more than 3hours. I have to drive about 5 miles before it works again? Anyone have any idea's? by the way, its a 98 auto disco.
Thanks

 

[basstard440]

I don't know if this is your problem but I had a Pontiac that the tac would act crazy when the battery was running low.

 

[joey]

There is also a wire on the back of the Alternator that can become loose and cause tach issues, but if it works fine after a certain number of miles I would say basstard440 is dead on. Check the battery.

 

[jusjay]

Thanks guys, I throw the load tester on the battery and see what happens.

 

[oscarthegrouch]

I have a 3.9v8. Tak doesn't work if there is a problem with the charging circuit. Mine did the same thing. New battery didn't solve the problem so the alternator was replaced. worked fine for a while until new alternator went U/S. Dealer had fitted alternator that couldn't handle the strain so I replaced the Lucas standard part with a heavy duty Denso. Problem solved.

The tack problem was intermittent to start with before becoming permanent. Discharging battery also makes the ABS fail and the light will come on, as will the SRS light for the airbags.

 

[FiveO Disco]

Charging system and or alternator

 

[wolf]

my tach went goofy a couple of years ago and then quit with the charging light coming on solidly - changed out the alternator (a very fast job on the Disco I 1997) and problem solved! One thing - be aware that your Serp belt tensioner bearings can start to go and that in turn will make your alternator's bearings over-work (that was what happened in my case).

Both alternator and belt tensioner are easy jobs to do at home (just make certain you have the nice long belt tensioner pulley wrench to slacken the tension on that pulley or you will be sweating bullets)