Old 535 cutting out

[luckyone]

My old 89 535 has a strange fault where every so often while driving in any style the engine will cut out & the ABS light comes on. It comes back with in a second or two but it’s getting on my nerves.

Has anyone heard of this before?

I’ve been told the ABS light coming on indicates a loss of electrical power, but I’m not sure where to start, I’ve checked the battery connections etc…

[fixedwheelnut]

Is it a 6 pot or early V8 ?
I would start with the ignition switch or DME relay [5 pin white or pale green one]wire up a test light and see where you are losing power.

[dazren]

An 89 would be a 6 cylinder.

DAZ

[luckyone]

Yep - 6 cylinder.

The problem is that I only lose power for literally 1 or 2 seconds then it’s all normal again, so tracing the power loss is a bit tricky!

I may well try sticking in a new relay – would this failing cause the car to lose all it’s power?

Just reminded my self that I think the last time it happened in the dark the lights went out also. Where is the main bolt in fuse when the battery is under the back seat? I couldn’t find it last time I looked & forgot all about it

[fixedwheelnut]

The main link fuse is either under the back seat near the battery taped up in line with one of the smaller main battery cables or under the bonnet by the right hand top mount suspension turret, but that normally effects central locking and electric windows more than engine/lights etc.
Could be ignition switch or even a battery dead short, if it effects the lights that rules out the DME relay as that would only effect the engine management.

[luckyone]

fixedwheelnut said:

The main link fuse is either under the back seat near the battery taped up in line with one of the smaller main battery cables or under the bonnet by the right hand top mount suspension turret, but that normally effects central locking and electric windows more than engine/lights etc. Could be ignition switch or even a battery dead short, if it effects the lights that rules out the DME relay as that would only effect the engine management.

Thanks for all your help! I am still having trouble locating the main fuse though. My dad had a 520 with the main fuse next to the battery on the turret, which failed causing, as you said, central locking probs. But I can't find any thing that looks like his fuse any where under the bonnet or under the back seat. The only thing I can see is something that looks like it is in heat shrink in the power line, under the back seat next to the battery - is that the fuse?
I realise you don't think it is the fuse, but have been having this problems for a couple of years now & it got really bad a one point. So out of desperation I tried cleaning the battery connections, which seemed to help, but now I wander if just moving the cables moved that fuse (if that’s what it is) easing the problem.

Failing that is the ignition switch a single part I can replace easily or is it wired to the loom & /or attached to the barrel?

I have gone through a couple of batteries since the problem first occurred so it shouldn't be that!

Sorry to keep on, but it's something I like to get to the bottom of so I can take the car on the track, it's just to dangerous as is it, if it cut mid bend I'd fly off!

[fixedwheelnut]

yeah that will be the fuse wrapped in heatshrink