xjs 1990 top will go up but not down
 

can anyone help? my top suddenly stop going down, yet will go up. checked the pump and other basic vitals, may be a faulty switch? any suggestion appreciated.
steve

Most likely a relay. They do tend to fail over time. You need heavy duty 40 amp relays, most standard relays are 30 amp. I bought them from an electronics supplier (digikey) rather than a parts store, but either should work.

Not sure about a 90, but my 94 has them in the trunk next to the pump. There are relays for the top up and top down, and windows up and down. At this age, replace them all.

steve,

When you try to put the hood down, do the windows go down? If the windows do go down, it's most likely the hood Down relay. If the windows don't go down, then it's most likely the switch, as it's unlikely that the windows Down & hood Down relays have failed at the same time.

Of course, this is always assuming that the hood always goes up. Remember the most likely cause of failure of hood not going down AND not going up is the handbrake switch. But, if as you say, it does go up, then that's not the problem.

Good luck

Paul

Try swapping the up and down relays to test them

xjs'90 conv. hood goes up not down
 

thank you all for your feedback. appreciated.
i swapped the replays (only the wood) and they both work but same thing only the up function works. Paul advised to replace the whole 6 relays? should i? where could i buy them? may it be also a faulty switch and if so where can it be bought? the area is super clean and pump work very well, i can hear the 'click' when i push the up button but not the down one.
thanks for your further jaguar experienced suggestions.
steve

oops, sorry for the typos... i swapped the relays (only the hood one)...ther rest of text is fine.

Could be the switch. This is what you have? http://www.jaguarclassicparts.com/il...es/DAC7529.jpg

Part #3 on the diagram. Console Switch and Cigar-Lighter - Parts For XJS from (V)179737 to (V)226645 | Jaguar Classic Parts UK

I would order the switch from the dealer or Jaguar Heritage in the UK (link above). You'll see aftermarket parts made by Uro, but if you look at the picture the original switch has metal springs on the edge to hold it into the wood trim, and the aftermarket switch has plastic. The plastic is too thick and won't fit, so the original switch is the only way to go.

Relays are something like this: CB1-R-12V Panasonic Electric Works | Relays | DigiKey

Digikey is fast shipping, and cheap.

Try swapping the roof switch for the Windom switch. I believe they are the same. The switches are the same on my 89

steve,

IMO, don't change all 6 relays, that would be a waste of money as it's not your problem. IF you're able to raise the hood and the windows then at least 3 of the relays are functioning.

First of all, can the hood definitely be made to go up? Put it in manual mode, lower it manually and then try and raise it. If that works, try and lower it. Do the windows go down even if the hood doesn't go down? If the windows won't go down either then try swapping the hood switch for one of teh window switches as suggested by BC XJS.

However, be very careful about removing the switch plinth. It invariably cracks. It's safe to actually remove the ski slope intact and then just swap over the window and hood wires underneath to test the switch.

Good luck

Paul

Mechanically, the switches are all the same.

Not necessarily! The system is a bit odd, in that when putting the hood up, the ground path is through the 87a terminal of down relay. Similarly, going down, the ground path is through the up relay.

The catch is the relays are rated differently for the primary and secondary contacts, so it might be rated at 40A through the 87 terminal, and 30A through the 87a terminal. So the relay will work when the coil is engaged to raise the hood, but not work as a ground path for the down operation since it is is rated for a lower current and the contact can burn and be non conductive - but only one way, the primary contacts can still be ok.

Took me a while to understand that a relay can only be half good!

Jagboi64,

That's fascinating! I'm going to go and re-educate myself on this section of the wiring diagram!

Cheers

Paul

xjs 1990 top will go up but not down
 

thank you JagBoi64 going to follow your advise, found a relay from my Jad dealership (OEM) and look forward to a successful outcome.
would you know where i can locate an 'how to' replace the switch? seems pretty straight forward but one never know.
thanks
steve

I'm going from memory on my 94, so I might miss a step or two.

Open the armrest lid and remove the trim piece at the front that has the catch for the lid. Under that there should be some screws that hold the wood down, remove those. Now you should be able to lift the rear edge of the wood up. You can get a hand underneath to release the wiring connectors to the switches, it's a tab on each end I think that needs to be squeezed.

Once the wires are disconnected, it's easier to lift up the wood trim and pull it out. The switches are in a plastic frame, which snaps into the wood. Not sure if it has to come out to remove the switches or not, I can't remember. The frame is likely very brittle, so be extra careful, or order another to have on hand for when it breaks! Part number is BCC2303.

Squeeze the metal tangs on the ends of the switch and it will push out. You may be able to do this from underneath and not disturb the other switches or need to completely remove the wood, depends on your hand size.

Connect the wiring to the new switch, snap it into place and put everything back as you took it apart.

Just as an aside, the screws on these cars that look like a Phillips head are not, it's actually a Pozidrive screw. They have small hash marks at 45 degrees to the main cross as an identifier. A phillips screwdriver will work, but the proper one does work better.

Steve,

I know I keep asking but do the windows go down when you try to lower the hood?

If they don't, then don't start with the relay, but start with the handbrake (most common problem with hood non-operation) or the switch itself.

Good luck

Paul

Once you disconnect the switch take it apart and clean it. Take care not to loose any parts and remember how it goes back toget her. It only take 15 minutes to clean. If you aren't comfortable with that get some electrical contact cleaner and spray it between the rocker and the housing then, let it sit a few minutes then blast it out with compressed air. Repeat a couple times and the switch might work if it's not broken internally.