Waterproofing/Electrical Issue

noozeyeguy · 01-18-2010, 08:49 PM

Had an interesting day today... coming back from a weekend of dry-camping and ATV riding in the Mojave Desert, we ran into the latest iteration of the storm-to-end-all-storms currently besieging Southern California

No worries other than my usual windshield-wiper issue (the control unit shorts out when it gets wet... nice design feature National).

All of a sudden the engine started acting weird. It felt like it was hunting for gears, it would kick down then immediately upshift. I made sure the O/D was off (I usually leave it off while towing)and dropped into 3rd. The motor wouldn't rev above 3k. We limped into Palmdale and I started trying to trace down the problem.

The more I thought about it the more I became convinced the wiper short and the engine problem were connected... and weather-related. I popped the "hood" and checked the fuse block; there was some water pooled on top of the box. Opening it up, I found the inside cover was dry but one thing jumped out at me: the fuel-pump relay is located at the upper-outside corner of the fuse block... hmmm.

I pulled the relay and found that there was a light coating of rust on the terminals. Voila! Obviously water intrusion is an issue. It must be collecting between the back of the fuse block and the firewall, then I guess the wind pressure pushes the water into the terminals from behind. The corrosion and moisture could easily cause a short to ground under load... exactly the symptomology the moho was exhibiting.

A few squirts of WD40 and a wipedown later, we chugged out onto surface streets to see if that was indeed the culprit. Engine ran fine, even the wipers were working normally (they saw what happened to their buddy Mr. Relay and decided to straighten up and be serious, I guess

). Just to be safe, we stayed off the freeway into the San Fernando Valley. Made it home finally, no further issues... so I'm going to proceed under the assumption that my initial diagnosis was correct. Once this part of the world dries out I'll pull the fuse block and pack the back of it with dielectric grease, that should serve to keep the water out.

So... long story short: Anybody else ever have this problem?

Belgian · 01-18-2010, 10:22 PM

We had the same problem with the wipers on our first trip after buying our Dolphin. Found the same answer about using dielectric grease in the connection and haven't had a problem since. Thankfully we have not had the engine problem. But I will be checking the fuel relay tomorrow. One other solution I have seen here at IRV2 is to add rubber stripping to the hood opening to stop the water from entering the front of the engine compartment. Thanks for the heads up on the problem.