Fuel and Temperature Guage problems

AS Harmony on 2ltr Petrol Pug Boxer

Following a fuel pump replacement and cam belt & water pump change, all by a qualified mechanic, the following problems have arisen.

Fuel guage not working and the mechanic subsequently fitted an auxiliary digital one in the glove compartment. This worked ok for a few days but now when you turn the ignition on the digital readout fades to zero.

Following the cam belt/water pump change, carried out by the same mechanic, the temp guage has ceased to work. This despite the system being properly filled and bled.

The veh recently suffered problems with the 15 pin fuel control relay that sits behind the air cleaner in the engine bay and fitted behind the glove box fuse box. This relay controls the fuel injection system but I don’t know if it also has an effect on the dash board gauges.

Not having a workshop manual for the base veh I’m somewhat at a loss as to how to sort these probs out.

It could be something as simple as a bad earth connection but I can find only one from the battery Neg to the chassis near the radiator. Are there any more, if so where?

Any hel would be greatly appreciated. Thank you.

Grahame

On vehicles of that age, it was common for the instruments to be fed (within the dash) by a separate 12V regulator, so that their readings did not change as the vehicle battery state of charge changed. If multiple instruments stop working at the same time, it's worth checking to see if that regulator has failed.

As Roopert said older vehicles had a regulator sometimes called a voltage stabilizer. On some vehicles it was fitted to the back of the instrument cluster.

Thanks both Roopert & Dave 418. Knowing nowt about regulators etc I’m still flummoxed. What does it look like and how can I get to it. Does the dash have to be removed or is it accessible from the engine compartment. Any info greatly appreciated..

As Dave418 says, a better term is stabiliser. Unfortunately the details vary a huge amount from vehicle maker to vehicle maker. On British cars it was often a metal-cased device that looked very similar to a relay, although on my 60's car it was a small rectangular metal can bolted to the back of the (wooden) dash! They are typically fitted under the dash.

I would start by looking in the equivalent of the Haynes manual for the base vehicle, as you can often figure these things out from, for example, the colours of the wiring attached to various bits under the dash.

By the late 90's I would not be surprised to find that it was an integral part of the dash cluster.

Having said that, it may be that multiple sensors in the engine bay (i.e. the input feeds to the dash instruments) share a common earth point, and if that were compromised, you could lose several gauges at once. Typically you would start diagnosing a fault like this with a meter at one end or the other - so for example start with the sensors and trace the wiring through to the dash.

Have you had a good look in the engine bay to check there are no sensor wires that have been left off, there is normally a sensor on the engine block for the temperature and the top of the radiator for the cooling fan, the fuel gauge could be an earth wire not connected,

seams funny that they both stopped working when the mechanic worked on associated parts , the fitting of a digital one in the glove box is a bodge job by him and I would not be happy with that , if everything was working when the van went in it should be returned like that, find another mechanic. Have you tried the Peugeot forum

Thanks for your responses gentlemen. I'll get under the bonnet and do what I can to check out the dash board - meter in hand. Incidentally, I've just remembered that's the I do have a Peter Russick pocket manual for the veh, 
hopefully that will help. I'll keep you posted.

Thank you all.
Grahame

Possibly part the same problem could be fuse/relay related. The only fuse array I can find is in the LH side pax glove box and the only relay I'm aware of is the 15 pin fuel injection relay located on the bulkhead behind the air cleaner - are there any more tucked away? Does this relay serve anything else, if so what? Are there any other fuse boxes apart from that in the glove box - if so, where are they hidden. 

Thanks in advance folks.
Grahame

I have a vague memory that older vehicles used to have a little widget that sat on the back of the instrument cluster that was responsible for voltage regulation to the instruments. If that failed it affected both the temperature and fuel gauges.

Hi
On right hand drive mark 1 and mark 2 it is fitted u der dash between steering column and heater box, it is black and approx the size of a packet of 20 cigarettes not difficult to see and most likely the cause of the fuel problem. Best of luck
John Dean ( retired Peugeot boxer factory engineer )

Thanks John. Is it repairable or must it be replaced?

hi,
I retired 10 years ago , it was always replaced then, can’t say if it’s repairable now never done it sorry.

Thanks for your help anyway John. I too am retired, over 20 yes ago, and find it impossible to get under vehicles and dashboards the way we used to. By the sound of it ano domini has caught up with both of us. Best regards, stay safe and thanks for the info.

Grahame