Fuel Gauge, Dash Lights and Oil Pressure Light

[CPBerry2011]

Hi everyone. Hope everybody is good and looking forward to spending time in your buses now the weather has improved

I just got my imported '71 bus through its first UK MOT so was looking forward to driving her around this summer. However, I am hoping my engine doesn't need an overhaul as during my trip home from the test centre the oil pressure light started to flicker after about 1/2 hour of driving and when I was exiting the motorway on the slip road and changing down gears. It went off as I went back up the gears but would come on, flickering, whenever I change down gears/reduce speed when approaching roundabouts and T junctions. Any advice/pointers would be appreciated.

Also, my fuel gauge has stopped working despite having a full tank. It was recently working ok. Again, any clues?

Finally, my dash lights seem like they may have an issue as they work intermittently and when they do work they are quite dull. ..is this normal? It is the stock dashboard. The high beam light works when high beam is on but the blue light is very faint. Again, any help would be greatly appreciated. Chris

 

[subheatadey]

Maybe a earth problem?

 

[CPBerry2011]

Hi. Thanks for replying. Would a bad earth contribute to all the problems?

Cheers.

Chris

 

[sparkywig]

The flickering oil pressure light could be an oil pressure problem, as the situations you describe it happening are the times when the oil pressure is at it's lowest.
It may be worth swapping the switch to be sure, but think worn bottom end as a worse case scenario unfortunately.

With regards to the other problems, drop the dash pod off and check all the connections, and then run through Speedy Jim's fuel gauge checks.

"Pull the Brw wire off the "G" terminal on the gauge.
Connect multimeter to chassis earth (dash metal) and to the Brw wire. Set meter to Ohms range. It should read between Zero Ohms (Full) and 100 Ohms (Empty). More important, it should be quite steady even driving the Bus.

That test should help decide if the sender is faulty or not.
You can test the gauge by jumpering the "G" terminal (where Brw wire was) to chassis earth. Gauge should go to FULL."

More on his website.
http://www.SpeedyJim.net" onclick="window.open(this.href);return false;

 

[CPBerry2011]

The flickering oil pressure light could be an oil pressure problem, as the situations you describe it happening are the times when the oil pressure is at it's lowest.
It may be worth swapping the switch to be sure, but think worn bottom end as a worse case scenario unfortunately.

With regards to the other problems, drop the dash pod off and check all the connections, and then run through Speedy Jim's fuel gauge checks.

"Pull the Brw wire off the "G" terminal on the gauge.
Connect multimeter to chassis earth (dash metal) and to the Brw wire. Set meter to Ohms range. It should read between Zero Ohms (Full) and 100 Ohms (Empty). More important, it should be quite steady even driving the Bus.

That test should help decide if the sender is faulty or not.
You can test the gauge by jumpering the "G" terminal (where Brw wire was) to chassis earth. Gauge should go to FULL."

More on his website.
http://www.SpeedyJim.net" onclick="window.open(this.href);return false;

Thanks for that, will run through it this weekend :/

 

[rlepecha]

Hi everyone. Hope everybody is good and looking forward to spending time in your buses now the weather has improved

I just got my imported '71 bus through its first UK MOT so was looking forward to driving her around this summer. However, I am hoping my engine doesn't need an overhaul as during my trip home from the test centre the oil pressure light started to flicker after about 1/2 hour of driving and when I was exiting the motorway on the slip road and changing down gears. It went off as I went back up the gears but would come on, flickering, whenever I change down gears/reduce speed when approaching roundabouts and T junctions. Any advice/pointers would be appreciated.

Also, my fuel gauge has stopped working despite having a full tank. It was recently working ok. Again, any clues?

Finally, my dash lights seem like they may have an issue as they work intermittently and when they do work they are quite dull. ..is this normal? It is the stock dashboard. The high beam light works when high beam is on but the blue light is very faint. Again, any help would be greatly appreciated. Chris

Blue light for high beam is feint in my bus too, I presumed this was how its supposed to be. The rest of the bulbs are as bright as expected.

Sent from my 02_jbla668 using Tapatalk

 

[Stevec]

With the lights none of mine are bright especially the high beam blue one. Sounds like a silly question but you have tried turning the light switch??

 

[CPBerry2011]

With the lights none of mine are bright especially the high beam blue one. Sounds like a silly question but you have tried turning the light switch??

Yeah, think it might be the earth as it does work and it does loghten/darken but seems to do it erratically.

 

[subheatadey]

I'd check the earth points particularly the one behind your dash just inspect them for any dodgy wires and poor contacts, check the earth bracket near the windscreen, the headlights earth i believe via the headlight shells so these wouldn't be effected.

 

[67panel]

sorry lads but this is the 10 out of 10 answer.you have 3 seperate faults:-
1 oil light posibly sender unit or low oil presure or oil needs changing or engine getting too hot.
2dash lights dim ,the back lighting is controled by reostat on light switch .they get corroded and this causes poor conections so when you turn swith lights can fliker /go out.try some switch cleaner.this does not alter warning lights so dim light is poor bulb or dirt in lens.
3fuel gauge as said check for conection to tank unit and also check gauge by earthin terminal and see if it reads full.

 

[CPBerry2011]

Thanks for everybodys input, appreciating it

 

[newhippy]

With reference to the high beam light being dull, I have just had my instrument pod out for cleaning/fixing behind the blue lens is a factory fitted cover with a small 1/4 inch hole in the centre. You could take that out to make it brighter.

 

[CPBerry2011]

Had a fiddle yesterday and the dimmer on the dash panel does work although when you turn the switch its kind of erratic so going to take the switch out and clean it up. Still to sort the fuel gauge issue and high beam warning light.

 

[CPBerry2011]

sorry lads but this is the 10 out of 10 answer.you have 3 seperate faults:-
1 oil light posibly sender unit or low oil presure or oil needs changing or engine getting too hot.
2dash lights dim ,the back lighting is controled by reostat on light switch .they get corroded and this causes poor conections so when you turn swith lights can fliker /go out.try some switch cleaner.this does not alter warning lights so dim light is poor bulb or dirt in lens.
3fuel gauge as said check for conection to tank unit and also check gauge by earthin terminal and see if it reads full.

Hi, thanks for the reply.

Had a quick look for the terminal for the fuel gauge sender test but failed to find it. Where is it? Should i be looking under the bus or in the engine bay? Any idea of wire colours for 71'? Any guidance much appreciated!

 

[Todster]

The easiest place to find this terminal, is behind the dash, connected to the gauge. The only thing with testing here is that you cannot be sure that the reading you are getting is from the sender or if the cable is damaged/shorting to earth this will make the reading incorrect. Don't know the wire colour, but it will be the one connected behind the gauge. Ahh, I've just remembered, be careful removing this, as the spade is held into the instrument cluster by a plastic ferrule that prevents the spade from shorting to earth on the back of the cluster. I had a problem with mine, where the gauge was all over the place, it used to change by half a tank in time to the indicators, thats when I found that the spade behind the cluster was just touching the metal at the back.

If it were me, I'd test behind the dash, see what resistance was across earth to sender wire, and take it from there.

Cheers
Mark

 

[CPBerry2011]

Thanks Msrk. Really appreciate that. So to sum up I need to check for resistance beween the sender wire and earth behind the fuel gauge on the dash. I have never reallu used a multimeter so forgive my ignorance for asking this but what do i setting do I put the multimeter on to do this and I presume I place the probes on eavh of the contact points.

Sorry to be a pain, I appreciate your help

Chris.

 

[CPBerry2011]

sorry lads but this is the 10 out of 10 answer.you have 3 seperate faults:-
1 oil light posibly sender unit or low oil presure or oil needs changing or engine getting too hot.
2dash lights dim ,the back lighting is controled by reostat on light switch .they get corroded and this causes poor conections so when you turn swith lights can fliker /go out.try some switch cleaner.this does not alter warning lights so dim light is poor bulb or dirt in lens.
3fuel gauge as said check for conection to tank unit and also check gauge by earthin terminal and see if it reads full.

Hi mate.

I hope/think the oil light was due to the fan belt slipping. Changed the belt, waiting for my registration to come through from DVLA so can take her out for a spin. Only prob now is G light comes on briefly when I first start her up. Seems to stop once engine has ticked over a bit though.

 

[CPBerry2011]

Thanks to everybody for your input. New to bus ownership and new to aircooled so learninh as I go

 

[Todster]

Hi Chris,
You'll have to set your meter to test resistance, could be marked on your meter as Ohm or the symbol - http://www.rapidtables.com/electric/ohm.htm" onclick="window.open(this.href);return false;
One probe to earth, one probe to the wire that you have taken off the gauge. See what the resistance is.

I've got the tank out of my bus at the moment, so when I get home tonight, I'll post up some pictures with it out. I'm sure mine is pretty much about right. It may help.

Cheers
Mark

 

[Todster]

Hi Chris,

I've took my sender unit apart, and took the following photos. As Sparkywig says, full should be 0 ohms and empty 100 ohms. If you look at mine, its a little out.

Full





Empty





Cheers
Mark