All Instruments Failed w/Defrost

[Dave951M]

I was coming home from the mountains this weekend (where it rained every day) and while pulling into a gas station, ALL of the gauges went dead as did the defroster. Current line of thought is a ground. All fuses check OK. Car still ran ok all the way home. Wipers ok both on regular and intermittent. I don't think that the battery box leaks. Any ideas or suggestions of where to look? My first choice is the ground for the instument cluster.

Dave951M

[This message has been edited by Dave951M (edited 07-29-2001).]

[mideastmafia]

there is a fuse called "instruments"

try REPLACING the fuse even if it doesnt look burnt.


SHAUN

[Dave951M]

The fuse was the first thing checked. It not only looks ok, a meter confirmed it. I'm still looking.

Dave951M

[MBuck951]

When my gauges went dead after playing with the fuses, I had to unhook/rehook the battery. Reset the DME and all was fine.

[Lawrence Coppari]

Is the fuse hot? Is voltage getting to it. Prior to it is a relay, I would assume.

[MDESMOND]

Originally posted by Dave951M:
I was coming home from the mountains this weekend (where it rained every day) and while pulling into a gas station, ALL of the gauges went dead as did the defroster. Current line of thought is a ground. All fuses check OK. Car still ran ok all the way home. Wipers ok both on regular and intermittent. I don't think that the battery box leaks. Any ideas or suggestions of where to look? My first choice is the ground for the instument cluster.

Dave951M

[This message has been edited by Dave951M (edited 07-29-2001).]

I had this haapen to me and it turned out to be a relay. Check relay G2 in the fuse box (this is the k15 realy in the schematics). If this relay dies it doesn't pick up when you turn the ignition switch on and various loads such as the gauges will not work.

One easy way to check is to swap it with the horn relay (G13) as they are the same and see if this fixes your problem. If so, it's a cheap fix.

Note that all of the relay designations are from a 1986 951.

Mike

[Dave951M]

The beast is alive once more! There was a hole under the battery towards the front of the battery box. It was camoflaged by some trash, and a bit of dirt. The size was just under 1/16 dia. Since the car was parked facing downhill, any rain that went into the box, collected right over the hole. Small size hole, very slow leak, all water concentrated over the hole and presto- electrical gremlin. I dried it out, fixed the pinhole and everything seems to be ok. The hole is in a place where unless the car is parked facing down a fairly steep hill, it doesn't leak at all. The hole is so small that it's barely visible. Thanks for the suggestions and help.

Dave951M

[Dave951M]

I spoke too soon. The gauges died again along with the other stuff. I checked the DME, ok, checked the ground bus on the firewall behind the glove box, one bad connector, fixed. Still no gauges. I'm trying the relay idea next, this is getting mondo frustrating.

Dave951M

[MDESMOND]

Originally posted by Dave951M:
I spoke too soon. The gauges died again along with the other stuff. I checked the DME, ok, checked the ground bus on the firewall behind the glove box, one bad connector, fixed. Still no gauges. I'm trying the relay idea next, this is getting mondo frustrating.

Dave951M

Dave,

I had this same probelm (gauges worked intermittently) and it turned out to be the relay. At first I thought that it was the ignition switch but it turned out to be the relay I mentioned in the earlier post.

Good luck and let us know how it goes.

Mike

Let me know how the relay

[Dave951M]

Problem solved, I think. The relay was indeed going bad intermittently, that coupled with a bad ground on the firewall behind the glove box made for an interesting troubleshooting session. For those who haven't been through this, there is a ground bus on the firewall with at least 8 circuts grounding there. One of them was kinda cruddy and making intermittent contact. Couple that with a flaky relay and the result is the failure of several seemingly unrelated systems.

MDESMOND- thanks a bunch for the relay tip, now my horn only works intermittently, and who really needs that.

Thanks for all the ideas and advice.

Dave951M

[MDESMOND]

Originally posted by Dave951M:
Problem solved, I think. The relay was indeed going bad intermittently, that coupled with a bad ground on the firewall behind the glove box made for an interesting troubleshooting session. For those who haven't been through this, there is a ground bus on the firewall with at least 8 circuts grounding there. One of them was kinda cruddy and making intermittent contact. Couple that with a flaky relay and the result is the failure of several seemingly unrelated systems.

MDESMOND- thanks a bunch for the relay tip, now my horn only works intermittently, and who really needs that.

Thanks for all the ideas and advice.

Dave951M

Dave,

Happy to see the problem is solved. You are right that this can be a painful diagnosis. I was halfway through pulling my ignition switch out before I decided to take another look.

FYI the Automotion part number for the relay is 141.951.253 B, (up to 1988 951) cost is 14.20 so it's a cheap fix. I am sure our friends here at Pelican can hook you up.

Mike

[julahti]

This tip solved my problems as well. thanks a lot!
Got to go to find a new relay now.