RangeRovers.net Forum banner

1 - 12 of 12 Posts

·
Registered
1995-2002 Range Rover P38A
Joined
·
36 Posts
Discussion Starter #1
Sudden compressor failure, RL bag blowout, issues from jumping relay 20

Hi all, First off while many of my Q's are likely answered here somewhere, with the amalgom of all problems together I thought I'd condense into one post.

Rear bags were leaking, which of cousre meant compressor was working overtime. On recent pump up left rear bag blew (my bad, I know) and compressor shut off. Would not come back on automatically. But no faults were listed. So system was depressurized, air tank emptied, and over-temp switch in comp. likely triggered.
So after some research did the following: New rear bags, both. Jumped relay 20 and comp. turns on. So to refill air tank and ultimatley recharge the system but not lose my battery, manually ran comp. with engine running 10 mins approx. And end pulled of jumper wire, reattached relay and no compressor action. Turned engine off, would not restart. Get alt. malfunction fault.

So I guess the questions are: Do I need to rebuild/replace compressor if it wont engage automatically? Can manually running comp. while engine is running damage the alternator in only 10 mins? Damage battery? Best course of action from anyone who has encountered this scenario. Based on my knowledge or rovers, many I'm sure.

A bit wordy, sorry. Many thanks in advance.

michael
01 4.6 HSE
 

·
Registered
1995-2002 Range Rover P38A
Joined
·
32 Posts
Re: Sudden compressor failure, RL bag blowout, issues from jumping relay 20

Ok, ,,,,,the compressor running to fill the tank doesn't need the engine running, I would think the compressor could run for an hour at least before you could measure any volt drop on the battery. Is the battery a bit weak anyway, if you think 10 mins of compressor time'll knock it back enough to flatten it?
The compressor relay bypass definately shouldn't affect the alternator,( still makes me wonder how good your battery is:?:)
If the compressor runs ok with the relay bypassed, then the compressor's fine. Start by checking the relay, and work you're way back from there.
 

·
Registered
1995-2002 Range Rover P38A
Joined
·
36 Posts
Discussion Starter #3
Re: Sudden compressor failure, RL bag blowout, issues from jumping relay 20

oldironbloke,

Thanks for the reply. Battery's two years old max, with no overdo stress on it so pretty sure it's fine. Pulled relay 20 and replaced with similarly rated relay and still no function. Also checked fuse 44 and maxifuse 2, both look solid. If it is the over-temp switch, any thoughts on reseting it (if possible) aside from tearing down the compressor and rebuilding, which given the mileage 109K, might want to do anyways. Thanks much for the insight.
 

·
Administrator
Joined
·
27,802 Posts
Re: Sudden compressor failure, RL bag blowout, issues from jumping relay 20

"pretty sure it's fine" doesn't mean anything. Neither does battery age. If I were in your shoes I'd be running the electrical stickie tests above to check the status of your battery, alternator and cables. You can have a brand new battery and tip top alternator but with a failing cable or duff connection the resistance will kill you battery.
 

·
Registered
Joined
·
931 Posts
Re: Sudden compressor failure, RL bag blowout, issues from jumping relay 20

When the engine does not start,is it because the the battery is flat ie engine will not turn over or does it turn over but not fire?.

To test the thermal switch, remove a bit of the insulation from the orange wire going to the compressor plug.Do not disconnect the plug.Then wrap/connect a length of wire to the spot on the orange wire you have bared and connect the other end of this wire to a vehicle ground point.If the compressor now runs ,the thermal cutout has failed.You can buy a new one and replace it the compressor with a bit of effort or buy a new compressor.
 

·
Registered
1995-2002 Range Rover P38A
Joined
·
36 Posts
Discussion Starter #6
Re: Sudden compressor failure, RL bag blowout, issues from jumping relay 20

Thanks guys for the help. RRToadhall, engine does not turn over so I know it does seem like battery is suspect yet found it hard to believe running comp and engine wld drain battery, unless of course it was already weak. Will chk on that as well as jump the thermal switch. Thanks John for the tip. Had found that on youtube. These are great vehicles when they run...

Cheers to all.
 

·
Registered
1995-2002 Range Rover P38A
Joined
·
32 Posts
Re: Sudden compressor failure, RL bag blowout, issues from jumping relay 20

Like RRtoadhall said, it's well worth checking the main leads. Don't just give em a wipe and look at, you need to undo the battery leads all the way along from end to end, clean up the eyelets and the points where they attatch. A little bit of corrosion gives a huge resistance, enough to cause arcing. Certainly enough to stop the alternator from charging the battery.
 

·
Registered
1995-2002 Range Rover P38A
Joined
·
36 Posts
Discussion Starter #8
Re: Sudden compressor failure, RL bag blowout, issues from jumping relay 20

Good point. Will do. Also working on the dreaded H-Core O rings via glovebox route. Having lots of fun with both issues.
 

·
Registered
1995-2002 Range Rover P38A
Joined
·
1,851 Posts
Re: Sudden compressor failure, RL bag blowout, issues from jumping relay 20

Hi

The fuse that supplies power to the compressor and the starter motor is the same unit. Make sure your compressor has not burned its motor and fried the fuse. Sniffing the compressor will tell you as well as the discoulered paint on the housing around the electromotor.

The fuse is one of the very large fuses in your fusebox.

Regards

Jos
 

·
Premium Member
Joined
·
1,339 Posts
Re: Sudden compressor failure, RL bag blowout, issues from jumping relay 20

As already said, your compressor probably has a broken thermal switch, meaning you should be able to activate it, but the EAS wont run it automatically because of the (faulty) overheat signal. You can replace the thermal switch or bypass it as a temporary fix, but first make sure the compressor runs as it should.
Replacing fuse 40 should also solve your starting problems.
 

·
Registered
1995-2002 Range Rover P38A
Joined
·
408 Posts
Re: Sudden compressor failure, RL bag blowout, issues from jumping relay 20

Did the message display on the dash say max speed 30 mph or anything when the airbag failed? If so you may simply have a hard fault stored in the EAS module under the left front seat, make up a cable and use Storeys software to reset!
 

·
Registered
1995-2002 Range Rover P38A
Joined
·
36 Posts
Discussion Starter #12
Re: Sudden compressor failure, RL bag blowout, issues from jumping relay 20

Thanks Jos. Had checked fuse 44 and maxifuse 2, no breaks in either one. Like what the gentleman from Belgium mentioned it does seem the themal switch would be the likely cause. No fault msg re: max speed or failed air bag. Just failed alt. gearbox, etc. what seem to suggest a weak or failing battery. Been busy fixing the wife's Saab so the rover lies dormant in the driveway. Jealous no doubt of the spanking new f150 rental next to it. Will bypass thermal and see if that's the deal. I see a comp. rebuild in my future.

Thanks again mates.
Cheers.
 
1 - 12 of 12 Posts
Top