trigmk2
New Member
- Posts
- 2
- Location
- West country
Hi all,
I am currently being plagued by a problem on my 1997 ('R') Discovery 1 300tdi Auto ES.
Just as I was about to leave for a journey from my parents' in Sussex to my place in Gloucester, the Check Engine came on. I had no choice but to make the journey, so a quick check of fluid levels and I left. The car drove absolutely fine all the way but I noticed that my mirrors were no longer controllable (I like to dip the N/S while parking). I found that fuse #18 (rear wash/wipe, mirrors, gear selector lights) was blown. I replaced the fuse, but as soon as the ignition was turned on it blew again.
Bit of investigation around the electronics revealed that there was an isolator switch in the cab that was wired into the earthing circuit (body to battery). I removed this and some aftermarket spotlight wiring, then added an earth strap from the body to the battery.
With this removed the Check Engine light disappeared and the fuse stopped blowing. This gave me full functionality of the rear wiper and mirrors, along with illuminating the gear select lights (suggesting they are not at fault, not that time anyway).
A month later, and again as I am leaving Sussex, the Check Engine light came on and I lost the rear wiper and gear selector lights. It made the journey without any running issues.
I looked into it last night as a grounding fault, based on the last occurrence. I cleaned the existing chassis earth and added another strap straight to the battery, but the light stayed on.
I noticed a single white wire with brown tell and plug floating loose, so cleaned it and looked what it could connect to. The only thing close was what I believe to be the oil temperature sender above the filter. Still the light is on. I checked this plug against the earth and found it had .02ohm resistance, is that correct or does that imply that it is incorrectly making contact with the earth?
I got a multimeter and checked fuse #18 slot (as it was blowing 20A fuses and the multimeter rated at 10A I couldn't take a current reading). There was a constant ~12V passing through which I assume there shouldn't as none of the associated electronics were in use. Knowing that the constant current draw should be low, I put a 15A fuse in to check if it was a current spike when the ignition was turned on. The fuse blew immediately, telling me there is still a massive current draw through the fuse.
Apparently the cruise control is also run off this fuse, but that hasn't worked since I bought the car, but I unplugged the vacuum pump anyway, still no change.
It has an OBD port in the footwell, but I don't know if it is OBD or OBDII, there have been many people saying many different things...
Is there anybody who can shed light on this??
I have to assume that the fuse blowing and Check Engine light are part of the same problem as they arose together both times.
Any help or insights would be greatly appreciated.
Trig
I am currently being plagued by a problem on my 1997 ('R') Discovery 1 300tdi Auto ES.
Just as I was about to leave for a journey from my parents' in Sussex to my place in Gloucester, the Check Engine came on. I had no choice but to make the journey, so a quick check of fluid levels and I left. The car drove absolutely fine all the way but I noticed that my mirrors were no longer controllable (I like to dip the N/S while parking). I found that fuse #18 (rear wash/wipe, mirrors, gear selector lights) was blown. I replaced the fuse, but as soon as the ignition was turned on it blew again.
Bit of investigation around the electronics revealed that there was an isolator switch in the cab that was wired into the earthing circuit (body to battery). I removed this and some aftermarket spotlight wiring, then added an earth strap from the body to the battery.
With this removed the Check Engine light disappeared and the fuse stopped blowing. This gave me full functionality of the rear wiper and mirrors, along with illuminating the gear select lights (suggesting they are not at fault, not that time anyway).
A month later, and again as I am leaving Sussex, the Check Engine light came on and I lost the rear wiper and gear selector lights. It made the journey without any running issues.
I looked into it last night as a grounding fault, based on the last occurrence. I cleaned the existing chassis earth and added another strap straight to the battery, but the light stayed on.
I noticed a single white wire with brown tell and plug floating loose, so cleaned it and looked what it could connect to. The only thing close was what I believe to be the oil temperature sender above the filter. Still the light is on. I checked this plug against the earth and found it had .02ohm resistance, is that correct or does that imply that it is incorrectly making contact with the earth?
I got a multimeter and checked fuse #18 slot (as it was blowing 20A fuses and the multimeter rated at 10A I couldn't take a current reading). There was a constant ~12V passing through which I assume there shouldn't as none of the associated electronics were in use. Knowing that the constant current draw should be low, I put a 15A fuse in to check if it was a current spike when the ignition was turned on. The fuse blew immediately, telling me there is still a massive current draw through the fuse.
Apparently the cruise control is also run off this fuse, but that hasn't worked since I bought the car, but I unplugged the vacuum pump anyway, still no change.
It has an OBD port in the footwell, but I don't know if it is OBD or OBDII, there have been many people saying many different things...
Is there anybody who can shed light on this??
I have to assume that the fuse blowing and Check Engine light are part of the same problem as they arose together both times.
Any help or insights would be greatly appreciated.
Trig
