electrical issues....help thankyou please yes very much kindly!!

[badgerpoker69]

helllooooooo....

a have a technical electric-trickery type problem if anybody might hold the knowledge!

i'll list them, it's easier!

for reference the car is a 1992 J carlton 2.6 cdx auto estate. not many miles (103k) and it has been fitted with a brand new gm part alternator by a vauxhall garage.( a pro auto electrician diagnosed that the faults were caused by a dodgy alternator!)

1.  the fuel gauge/temp gauge dont work
2. the rev counter doesn't work initially, then when you rev the engine it bursts into life, but it pulses in time with a pulsing battery light and massively under-reads ( I checked the alternator output and it was a steady 13.9v throughout the rev range.)
3. the gearbox very occasionally will go into what i believe to be a "safe mode". where the "s" lamp will flash and the car will pull away in 3rd.
4. the "range" function on the lcd computer thing has a big "F" (presumably meaning "fault" cos the fuel the fuel gauge isn't working

all the problems above have now become intermittent since cleaning a multi-pin plug that plugs into a black plastic box located just behind the battery. is this just a coincindence or is this unit in some way connected to the dashboard

[Murph]

That unit sounds like the ABS relay box - wierd if so because the ABS isnt (shouldnt be) connected to the fuel guage..

Check the multiplug that's located by the airbox - opposite the battery.  This plug was responsible for problems with my 2.6 - it looked OK until I gave it a good jiggle and found it not connected properly.

I had no temp guage, intermittent fuel guage and the car would occasionally cut out.

Also, it will be worth hooking up a multimeter at the battery to check the voltage while the car is running - just in case.

[Whippit]

Most faults sound like a dodgy regulator on the instrument cluster.
http://totalcarlton.com/forums/index.php/topic,8959.msg71558.html#msg71558
Exactly the same fault here?
Though its VX dont rule out dodgy plug connections

The Gearbox..........does it tend to do it more in Damp weather?
Usual causes for this are damp in the ECU, or dodgy connections to the gearbox (usually the 2 plugs in the engine bay)
Give these and the ECU connector a good clean and make sure your scuttle drains are clear of debris.

[badgerpoker69]

the gearbox has only done it once since i've had it. also i'm not convinced that plastic box i mentioned is the one you're thinking of. it as a mini throttle cable running to the throttle linkage. thing is, since i've cleaned this plug the dials seem to work more than they don't! and very occasionally the fuel gauge springs to life, the "F" dissapears and the "range" function works. but then i can literally turn the engine off and re-start it 5 min later and nothing but the rev counter will work! do these items all share a common earth point? (first one to say "the chassis!!" gets wee wee in their tea! )

[Murph]

Aaah thats the cruise control actuator!

The cruise control is pretty self contained although it does take some info from the dash binacle.  Does your cruise control work - they usually dont!

[badgerpoker69]

it only works if i keep my foot really still on the accelerator pedal!! so basically...no! but the sunroof works fine..yeay!! somebody mentioned the multi-plug by the airbox, would this be the big one in the side? just thinking about it i think the daials only started working from time to time after i removed the airbox to modify it. i did it at the same time as messing with the plug on what has now been established to be the cruise control module. tomorrow i'll do a few con checks (or live checks if anybody knows what potential should be on what pin?) if it turns out to be this plug then the "profesional" auto electrician who diagnosed the fault as a dodgy alternater needs to be dressed up in a clown suit and sent to an I hate clowns convention!

[Murph]

This plug here is the one I was talking about.. the one in the middle of the pic.


The cruise is supposed to work without your foot on the pedal at all - give that a go...
It should hold a steady speed until you brake or accelerate.

As Whippit says, it will also be worth checking the ECU plugs for signs of damp.  The gearbox ECU is located under the black plastic cover at the bottom of the windscreen, passenger side.  It is possible to get at it OK without removing the wiper arms.

[badgerpoker69]

aye..that be the beasty! i'll give that a clean up with a fibre pen and see if that helps. cruise control doesn't work, saying it only worked with my foot on the accelerator was my poor attempt attempt at childish humuor wasted on a clearly intillectual audiance!

[Murph]

Intellectual?  Naahhhh!

I just seem to have left my wits in bed today LOL

[badgerpoker69]

it's definately that multi-plug! i wiggled the wires and all the dials worked including the fuel gauge, then wiggled them again and the dials would work then not work. so i've nabbed a generic 21 pin multi-plug/socket from work and i'm going to chop the old one out and fit this (the joys of being a RAF electrician..free stuff!!)

[Whippit]

Loving the bodge Murph

If in doubt Wedge it LOL

[Murph]

Thats how I found it!
It's not wedged at all but I'm notsure the bracketry is quite what it should be.

[badgerpoker69]

changed the plug for the new one, all the dials seem to be working so far except for the fuel gauge, it just refuses to play ball unless it feels like it! anyone know where the fuel sender is? (yes i know it's in the tank! but i can't find a plug for it!!) so a semi-success then! at least i wont be gettin done for going 108 when my speedo says 75!! (which it did!!)

[Pedro]

Glad you made it over here matey, and are getting things sorted!

[badgerpoker69]

yo!! yeah steadily getting there! the old girls done well considering it was sat under a tree for 8 months!! it sprung a couple of fuel leaks on me after the 1st couple of trips in it but they were very easily sorted. just got to get the fuel gauge working and also i've noticed that it's a bit reluctant to start first thing, it takes about 3-5 seconds of cranking before it fires (it could be that i've just been spoilt with german/jap engines that start as soon as they sniff the key!) and it also hunts between 400rpm and 900rpm when cold (do these use an idle stabalising valve?)  one thing that has really got me puzzled though, the aircon doesn't work (as expected!!) however, the compressor doesn't even come on, neither does the little yellow light on the switch. also there is a seperate kenlow cooling fan arrangement in the condensor with a switch on the dash. this has the thermostat set so it takes it's measurement from an engine coolant pipe which seems a bit odd to say the least. there is no power to this system either and i can't find any fuses for it!

[doz]

a lack of gas means the safrty pressure switch stops the compressor from running and so no little yellow light 

[Murph]

The idling will be due to the Idle Control Valve (ICV) being clogged with crap - nothing a good clean wont sort, and there's even a "How To" guide in the "how To's and FAQ's" section.


The aftermarket fan setup sounds quite common tbh - it sounds almost exactly like the one fitted to Jon Paxton's 2.6 estate - the control sensor was fitted to the top hose.

[badgerpoker69]

yup, thats how mine's rigged. i take it the aircon system in these uses the old type R12 cfc gas? can they be retrofitted to use R134a hfc gas?

[carlton_mad]

all depends on the size of the fittings larger fittings are r134 smaller r12

[chrismec]

all depends on the size of the fittings larger fittings are r134 smaller r12

Can be converted I think, big thread from Diplomat I think on here some where

[badgerpoker69]

i must admit i thought all the fittings were the same size, main incompatibilities are that r12 uses a mineral oil and the r134a uses semi-synthetic oil (or vice versa..can't remember, it's been 4 years since i did my C&G refridgerant handling course)) that will perish all the seals in an r12 compressor. not too fussed about one though reall, of all the other 14 cars i've owned this is the only one even came fitted with the potential to have air con!! main thing is i need to get the fuel gauge working cos i've ran it dry twicw already!! doh!!

[SJC]

Have you tried simply cleaning the connector on the sender itself?  I think the next port of call for the sender wiring is the instrument panel itself and the tripcomputer piggy backs off of it from there.

The other possibility, of course, is that you have a broken wire on that circuit - most likely around the area of the tank I'd say.  It's a blue/black wire.

[badgerpoker69]

i'll have a butchers today for that then! the fuel gauge does spring to life momentarily, usually when i first start the car then it stops working after about 5 min.

[doz]

Find the wire at the sender end and ground it out. Gauge goes to the top and stays there fault with sender unit. Gauge still fannys about dash and/or wire between sender and dash.

[SJC]

^ excellent advice