Hi everyone,

Well, its my first big trip in my 1998 H100 and 4 days in I'm nursing a flat battery. I managed to start the van buy bridging the engine battery (showing 11.6v) with house batteries (I've conevrted it to a camper) to get it running but only really have 1 or 2 more cold starts in the house batteries and cranking is not good for those batteries.

Unfortunatly I don't have a workshop manual to refer too, but I'm reasonibly compitent with fixing old cars (this is my first "modern" car and first diesel).

Taking a peak under the "hood" I can see a couple of ancilliary belt drive devices. The upper is driven by a double belt and looks like it has a hydraulic connection on the back (power steering pump??) the other down low has the characteristic fan behind the pulley, which looks like it will need to be accessed from below.

Obviously I need to get in there and have a good look for loose connections and fixings etc, but looking online at replacement parts (after recovering from the shock of the price) the pic's I find show the hydraulic fitting on the back of the atlernator.

So, My questions are:

1, What is this thing on the back of what might be the alternator? If not the alternator is this the powersteering pump?

2, There is what looks like a small relay box in the back of the battery compartment, what does this do? Should I be checking something in there?

3, Other than checking mounting & connection to the alternator is there anything else that people would suggest before I start getting carried away with my roadside repairs?

Many thanks.

This post has been edited by Finn: Sep 13 2009, 09:55 AM

welcome to the forums (IMG:style_emoticons/default/00000732.gif)

l does sound like you have a worn out battery or the battery is not being charged. you need to get a meter to check the charge rate.

if there is no (or little) charge check that the drive belt for the alternator is not loose, check the connections on the back of the alternator (and the battery). if this is all o/k then it is likely to be a faulty alternator.

the 'box' with the hydrolic pipe comimg out from it on the back of the alternator is a pump that provides pressure for the brake servo......this can be removed from the alternator if required when fitting a new one

the pump at the back of the alternator is actually a 'vacumm' pump for the brake servo.

does the charge lamp come on when your engine is running/driving on the road, that would indicate an alternator problem, otherwise check the battery condition first.

A bad battery wont hold charge and it sounds like your symptoms.

Attached page from the service manual.

the pump at the back of the alternator is actually a 'vacumm' pump for the brake servo.

does the charge lamp come on when your engine is running/driving on the road, that would indicate an alternator problem, otherwise check the battery condition first.

What's the voltage when your RPMs are 2000 and above?

A bad battery wont hold charge and it sounds like your symptoms.

Attached page from the service manual.

[attachment=14286:Engine_E...ystem_19.pdf]

Thanks for the responses.

Thats interesting as I couldn't a see a brake servo & wondered what was powering them.

I'm taking it to a local garage here tomorrow and have the battery charged for the day. I will also disconnect the house batteries and see if that makes a difference to the charging rate.

I am simply measuring the charge over the terminals on the on the battery. Usually I get 14 + volt, but seem to be getting 11.8 ish at about 2000 rpm. 11.4 volt at idle. Ill try and measure the voltage at the terminals on the alternator and see what that yields.

Any suggestions on accessing the alternator? Seems to be quite well tucked away.

Charge lamp goes out once the engine is running. Well sort of.... the charge light, park brake light & fuel filter light all came on at about 1/3 brightness 200 miles ago. They are dim enough to be difficult to see during the day, but deffo are turnign on/off. I have drained the fuel filter and checked the hand brake light switch, so figured it was a blip in the matrix. Charge does go off as expected.

Thanks for the wiring diagram, I'll try and get that printed off.
Thanks again.

This post has been edited by Finn: Sep 14 2009, 08:09 AM

I did a bit of exploring under my van last night and un bolted the alternator.
The pump on the back connects to the sumptuous via what looks like a 19mm rubber hose. It's difficult to see where the output hoses on the top are going too. Perhaps pumping oil to the forward mounted oil pump?
I think an alternator swap is going to be too much hassle to to roadside and may have to curtail my trip an do it at home where I have a better selection of tools.

I also wonder/if it is worth taking the radiator out to do the job which would give me access from/above/front as well? Any thoughts.

you shoud'nt need to take the rad. out but it would give you more room, it depends on your mechanical skill level

the vacuum pump on the back of the alternator does have an oil feed going to it

I fitted a 2nd hand alt yesterday and changed the oil and filter too.
I'm assuming that I don't need to do anything special like bleeding the oil feed to the vacuum pump? It looked like it was gravity fed from the oil cooler sandwich plate.
I had to tension the belts up pretty tight to stop them squealing. Like use a screw driver as a lever. 30 miles later the fan seems to be rubbing and the charging problem has returned - 3 dash lights on - haven't checked the charge but will do so tomorrow.
Any ideas?

the 3 lights went out ok once the new alt went in and was charging at 14 volt. The 3 dash light are on, but flash off occasionally while driving. I've only driven about a mile since the problem re-occured.

Any ideas would be helpful, it's just bit stressful.
Cheers

you do not need to bleed the oil feed pipe.

it does sound like you may have a weak or worn out second-hand alternator, you really need to check the charge rate before you go any further, also make sure that all the terminals on the alternator, battery and earth/ground leads are clean and secure

It turned out that the pulley was loose on the front of the alternator. Tightend it up and problem solved.

Thanks for the help.

However, as one challenge is overcome another emerges..........