Welcome to the new version of CMN!
Some help showing the new functions How-To

How-to: Browsing the forum effectively

JCB 801 boiling batteries

Discuss compact excavators here

Topic author
Bivvysenior
Posts: 14
Joined: Sun Jan 19, 2014 3:51 pm
Real name: Rom Swiokla
Been thanked: 1 time

JCB 801 boiling batteries

Post #1 by Bivvysenior » Mon Apr 20, 2015 10:45 pm

The battery is being "cooked" with a voltage reading of 18v measured at the battery terminals when running. I assume it is a fault with the voltage regulator not working correctly. Can anyone advise where it is located on the JCB 801 digger.
Any suggestion where I couild buy a replacement or is this a JCB dealer item only?


Jeremy Rowland
Moderator
Posts: 6821
Joined: Sun Aug 05, 2007 8:36 pm
Real name: Jeremy Rowland
Has thanked: 1034 times
Been thanked: 822 times

Re: JCB 801 boiling batteries

Post #2 by Jeremy Rowland » Tue Apr 21, 2015 7:51 am

Rom the battery voltage regulator is usually part of the alternator; it should be possible to find a company that will be able to repair your alternator or offer you a re-con job.

Jeremy


sdarmstrong
Posts: 112
Joined: Thu Feb 03, 2011 10:50 pm
Real name: david armstrong
Location: Ireland
Has thanked: 27 times
Been thanked: 12 times
Flag: Ireland

Re: JCB 801 boiling batteries

Post #3 by sdarmstrong » Tue Apr 21, 2015 1:46 pm

There is a seperate regulator on the 801. I think it's up high on the rhs of the engine and bolted to the back of the engine compartment. I done away with mine a good few years ago when getting a new altenator.


Topic author
Bivvysenior
Posts: 14
Joined: Sun Jan 19, 2014 3:51 pm
Real name: Rom Swiokla
Been thanked: 1 time

Re: JCB 801 boiling batteries

Post #4 by Bivvysenior » Tue Apr 21, 2015 1:55 pm

Thanks guys for the advice I will get out on site and investigate . I have ordered a regulator on spec from Holt JCB will let you know


Topic author
Bivvysenior
Posts: 14
Joined: Sun Jan 19, 2014 3:51 pm
Real name: Rom Swiokla
Been thanked: 1 time

Re: JCB 801 boiling batteries

Post #5 by Bivvysenior » Fri Apr 24, 2015 9:05 pm

Fitted the new regulator still the same problem 18volts on the battery when running.
Has anyone got a electrical drawing for the regulator and alternator? Or can you advise on how to locate the fault any help will be appreciated.


Jeremy Rowland
Moderator
Posts: 6821
Joined: Sun Aug 05, 2007 8:36 pm
Real name: Jeremy Rowland
Has thanked: 1034 times
Been thanked: 822 times

Re: JCB 801 boiling batteries

Post #6 by Jeremy Rowland » Fri Apr 24, 2015 9:54 pm

Bivvysenior wrote:Fitted the new regulator still the same problem 18volts on the battery when running.
Has anyone got a electrical drawing for the regulator and alternator? Or can you advise on how to locate the fault any help will be appreciated.


I can't help you with a wiring diagram but I would suggest checking all of the terminals on the alternator and the regulator; you really need an vehicle sparky to sort this kind of problem unless your very adept at using a multimeter.

Jeremy


Topic author
Bivvysenior
Posts: 14
Joined: Sun Jan 19, 2014 3:51 pm
Real name: Rom Swiokla
Been thanked: 1 time

Re: JCB 801 boiling batteries

Post #7 by Bivvysenior » Sat Apr 25, 2015 7:11 am

Hi Jeremy
I am Ok with the use of a multi meter, My problem is to try to get access to a electrical drawing to see what is missing. As there is a 18v reading on the battery when running the engine I am assuming that the regulator is not latching one of the relays to reduce the output.


Jeremy Rowland
Moderator
Posts: 6821
Joined: Sun Aug 05, 2007 8:36 pm
Real name: Jeremy Rowland
Has thanked: 1034 times
Been thanked: 822 times

Re: JCB 801 boiling batteries

Post #8 by Jeremy Rowland » Sat Apr 25, 2015 6:14 pm

Bivvysenior wrote:Hi Jeremy
I am Ok with the use of a multi meter, My problem is to try to get access to a electrical drawing to see what is missing. As there is a 18v reading on the battery when running the engine I am assuming that the regulator is not latching one of the relays to reduce the output.



Ok Rom I hope that somebody on here can provide you with the circuit drawing.

Jeremy


2414.ginger
Posts: 8
Joined: Mon Nov 05, 2012 10:01 pm
Real name: pete
Location: Somerset
Has thanked: 1 time
Flag: Great Britain

Re: JCB 801 boiling batteries

Post #9 by 2414.ginger » Sat Apr 25, 2015 10:51 pm

OK I have a service manual that seems to have an extensive section on electrics, if you send me a PM with your email I will send you a copy.
Pete


Topic author
Bivvysenior
Posts: 14
Joined: Sun Jan 19, 2014 3:51 pm
Real name: Rom Swiokla
Been thanked: 1 time

Re: JCB 801 boiling batteries

Post #10 by Bivvysenior » Tue Apr 28, 2015 5:13 pm

Thank you Pete for the pdf manual for the JCB 801 The manual quite doesn't cover my machine as it is older. However, it more than explained the electrics bar a few diodes in circuit I can say it is almost identical.

So armed with the information I discovered
1. What I thought was an alternator light was in fact the oil pressure warning light fitted to wrong socket in the panel I had assumed this was telling me the alternator was OK .
2. When I put the oil warning light in the correct socket, and a working bulb in the altenator warning light socket the alternator warning light was found to be permanently on.
Therfore the relay in the regulator was not being latched to extinguish the light when running, it identified that no 5volt voltage was coming from a tap winding in the alternator. A routine continuity of the wiring found no faults
Checked with JCB and found that two types of alternator available a 35amp or 40amp. My machine being the older model was no longer subject to service exchange and therefore commanded a higher trade price of £243 . The reason for the price difference they could not get spares to refurbish the older faulty units.
Took a leap of faith and ordered a alternator to fit.
Will fit when it arrives .


Return to “Compact Excavators”

Who is online

Users browsing this forum: No registered users and 1 guest