I am fairly sure there are TWO switches on the foot brake and yes one is for the brake lights. It's the other that's the interlock.

Elec. guide will show.

 

Peter this car is not your dads Buick! First you should read the OBDII codes and document them (not what they mean the real codes) then clear them and see what comes up again.

The shifter interlock not allowing you to move the shifter is controlled many things and I am providing a wiring diagram link for you to look at.

Link http://www.jagrepair.com/images/Auto...x2062004en.pdf

The car not going over 1000RPM tells me it is in restrictive performance it will limit the RPM’s and when it is in “P” or “N” it will also limit the RPM’s

You need to read the codes and then post them so we can see what is going on.

 

I got a new J-Gate for very cheap second hand. Unfortunately that did not solve the problem. Furthermore, I also checked the brake switch under the steering wheel. JagV8 was correct, there is two. The one which controls the J-Gate is not working. Is there anyway to over-ride this?

When I start the car, by jumping the relay and select reverse, by manually over-riding the safety switch in the J-Gate there is a sudden jump into gear. Then when I select drive it takes alot of revs to get moving, as if it is in the wrong gear (maybe in 4) instead of 1.

Also, when I select the sport button on the J-Gate nothing happens.

I have checked the bolts on the gearbox and they are all tight, but would it be possible that the gearbox and J-Gate gears do not match. Would this stop the car starting/ working correctly?

Ps - thanks Gus for the electrical diagram. I will look through it.

 

I've read the codes and no error is coming up on the handheld device.
I'm struggling to figure out how to get this car going. I'm going to look on the side of the gearbox (Drivers) to make sure all the wires are connected later today.

Is there anyway to over-ride the brake switch?

so to review:

- The bolts on the side of the gearbox are tight.
- The brake interlock appears not to be working.
- It won't start in P.
- It wont allow the shifter to be moved out of P

How I start the Car:

- Remove Relay and jump connectors.
- Runs and revs freely upon accelerator application.
- By manually releasing safety switch on the shifter I can select gears.
- Large thud when selecting reverse.
- When selecting 'Drive' it takes a lot of Reving to get the car to move. As If it is in high gear.


Any final tips or ideas before I brake her, or throw her up as Spares/ Repairs?

Thanks

 

It seems you've identified the relay as one of your problems. May I ssuggest you replace it rather than continuing to jump it? It won't fix all the other problems you've noted, but you will correct one of your problems.

Also the sport switch affects the shift pattern of the transmission. With the switch activated, the tranny shifts to the next higher gear at a higher RPM. In my experience, the sport switch has no effect unless the car is in gear and moving.

 

Given that you've only spent 30 quid and a few days time poking around, this seems a little premature.

I'd fix the brake pedal switch first as you'll need that to work once the transmission issue is resolved. If you're sure that the J gate and cable assembly is fine, move on to the transmission next.

Have you checked fluid level?

 

Hey Guys. Thanks for all the replies. I swap the relay with another one which is the same, and still had the issue - so the relay is perfect. But thanks for the tip!

I haven't looked at the fluid level yet, but yes now that you mention it that could be the cause of some of my issues regarding it taking lots of revs to get the car moving.

Does anybody know the correct name for the gearbox switch on the brake padal. I've been searching eBay but cant seem to locate one. Is there a way to by pass it, to allow the car to start? Am I correct in saying this will stop the car from starting.

I'm starting to think there is a problem with the gearbox ECU, where would this be located? is it inside or the outside of the gearbox? Thanks for replies!