How do I keep rain from affecting my cluster connections?

[mtnbob]

Every time it rains my tach starts acting weird, battery charge idiot light comes on, oil pressure idiot light comes on and engine appears to overheat. The engine isn't overheating and the pressure is great. Is it just water hitting the contacts? Is there a way to clean the contacts on the alternator and oil pressure sensor and then maybe coat them with something to protect them? would shrink tubing help or something else maybe??
Thanks
Robert

[Doug]

I doubt that the problem is under the hood. More likely you have a rotten windshield sill and seal leaking allowing the water to drip through the electrical cluster behind the dash. Check for signs of water damage there. As an aside check your rain tray (where the wiper motor and meechanism lives) drains to make sure they are open. This can also cause water to back up flooding into the back of the dash area.

[duffer]

I doubt that the problem is under the hood. More likely you have a rotten windshield sill and seal leaking allowing the water to drip through the electrical cluster behind the dash. Check for signs of water damage there. As an aside check your rain tray (where the wiper motor and meechanism lives) drains to make sure they are open. This can also cause water to back up flooding into the back of the dash area.

Or...

Alternatively...

Buy a 15ftX20ft tarpaulin,
secure it to your car with
strong cord, cut a small
hole, so that you can see
where you're going and
head out on the open road  :lol:

[mtnbob]

:? funny----   anyone have any serious suggestions? There are no windshield leaks. Could water getting on the sensor contacts under the hood be doing this?

[Baselyne]

I for one know im having this windshild leak problem! All rabbit's ive seen have this problem....

I'd say that's a pretty serious take on whats happening!

[clbanman]

If you suspect that underhood is your problem, wait till it's raining and the problem crops up.  Hose down your alternator connections and any connectors you suspect with WD-40 and if that is the cause, it should go away. (The WD-40 will displace the moisture).  
Having said that, I would agree with the others that it is far more likely that it is water coming through the body around your windshield.  A quick test that I wouldn't necessarily recommend at this time of year is to turn on your water hose and run water down the windshield in various areas to see if you can trigger the problem.  That should help nail the area down.  Do you have a problem with windows fogging up?  If so, that is often a sign of leakage into the cabin even if you are not seeing visible water.

[duffer]

:? funny----   anyone have any serious suggestions? There are no windshield leaks. Could water getting on the sensor contacts under the hood be doing this?

My apologies if I offended you, in any way.

It was approaching 3:00a.m., I was a little light-headed and a couple of Drambuies didn't help.

Sorry for not taking things more seriously.

[mtnbob]

Not a problem, no offense taken This group has been fantastic for a new diesel vw owner!!! Without it I'd be sunk. Maybe I dismissed the windshield leakage problem too quickly. I had a new windshield put in 6 months ago, and all was bone dry when I put in a new cluster a month ago, but maybe I need to look at the drip tray to be sure. It was pretty dry here a month or two ago, but now we are getting a lot of rain. :shock:

[TedV]

check for the water leaks.  

check for poor connections or corrosion on electrical connectors. Add dielectric grease on contacts to help prevent the corrosion in future.

could be a bad ground or short only seen when you turn on headlights and wipers. get wire diagram and see where all those circuits interact. Turn stuff on, see if you can reproduce when dry.  Hose down parts of car to duplicate.

Alt belt good and tight? if so, rain water will let belt slip when wet.

hows that for a lil list of straws to grasp at?  :wink:  :lol:

[mtnbob]

To start with the alt belt and a/c belt are loose and I'm having probs trying to figure out how to tighten it. :shock: I have the Bentley book out but still puzzled Going out to try again

[burn_your_money]

Good luck. AC is the devil. There are lots of hidden bolts and adjusters that need turning in order to tighten the belts, I prefer to rip the AC out

[rabbitman]

Do you have the plastic rain tray to keep water out of the heater? I know when it rains I get lots of water on the fuse panel, I put a plastic grocery bag above it and I think it helped. Water also dripped on the passengers feet but I think I solved that by unclogging the drains in the rain tray.

[mtnbob]

yes the plastic rain tray looks ok. I got all the belts tightened. What a PITA!! I'll get some dielectric grease tonight. I wonder if a very loose alt belt could cause fluctuations in voltage resulting in sensors acting weird. It would have been made worse by wet weather making the belt slip. Just wondering.  :shock:

[rabbitman]

Maybe try unplugging your alternator and run the car and see if anything gets weird. I wouldn't think a slipping belt would do what your seeing. When I drive my rabbit through deep (1ft) snow drifts the belt slips and the lights dim a little bit for a few seconds then the belt catches and everythings back to normal, I don't have a factory tach though.

[DonGTI]

Not sure if what you're seing is anything like this but here it goes:

One day it was raing vey heavily and went through some flooded roads with my U-boat i mean Golf (had lights and wipers on). After the first few puddles the alternator light turned onn and stayed on at low revs, kept going. Oil light came up but was sort of dim and constantly ON. After some time I started seeing gauge abnormalities... The temp gauge, the fuel gauge and the digital MFD oil temp were all showing 25-40% in excess of what they were a few seconds before! Kept going, parked in garage and next morning started up and went out again. Although there was no rain, Temp gauge, MFD Oil temp and Fuel gauge were all showing 25% more. On turning on the lights the oil light turned on and stayed on.

Before i started messing around I hosed everything with 2 bottles WD40 but to no avail. Then came all the things my electrician suggested and ended up doing himself :

Replaced rectifyer/regulator on alternator - Nothing happened
Replaced some wire connections to various sender units on engine - Nothing happend
Replaced light switch - Nothing happened

At this point i was banging my head on the wall when i decided to take the cluster out and check it using the factory workshop manual. Whilst removing the dash I found

- the Earth wire (some german genius coloured it brown) of the light switch was burned at the core with the plastic insulation peeling/crumbling off.... Followed wire to fusebox, replaced it from end to end... amazingly no blown fuses. - CHANGE ! oil light stopped turning on when lights switched on

- took dash cluster out, was dry and with no water evident, replaced regulator  on back of cluster, gave cluster another Earth for no reason whatsoever, bolted everything back up and all was back to normal...

Went through some large stretches of flooded road after a few weeks and nothing happened again... Still clueless as to what actually happened tho since no explanation make complete sense...