Cruise control retrofit

[karl1171]

I've searched the forums but can't really find any details.

Is it possible to fit the cruise control from a 730 auto to my 525 manual (same year)?

What parts are required, where are they located in the donor car, and where do they fit on the 525?

[genphreak]

IF you are talking M30 to M20 some parts will be similar, but there are major differences. The electronics will probably look the same but be different. You can go off part numbers- but I'd say the answer to your question is, on balance, probably really... no.

[myles]

You can use some of the parts, depending on production dates of both cars. I've done it on 3 E34s and 1 E36. First thing to check is to see if your car is pre wired for it. I've never seen an E34 which isn't but it's possible that it doesn't have it. E32s use the same system. If your car has EML or ASC this may not be correct.

The switch - There are a few different types of switch. The switches are different depending on if the car has a drivers airbag or not. You will also want to look to see if your car needs the 2 wire or the 5 wire type. 5 wire type is used on most cars. I've fitted 5 wire switches to all cars. The 2 wire type might be used on cars with EML.

The actuator - All E34s and E32s use the same one. Pre 09/94 E36s have the same actuator as the E34.

The actuator mounting bracket - These will be different depending on the type of engine and model. M50 and M20 use the same bracket.

The cruise throttle cable - they use different ones depending on the engine model. M50 and M20 use different cables. I always buy new cables.

The brain - In 09/91 they changed the brain. In early cars it's in the e-box next to the engine ecu, but in later cars it is behind the front left footwell speaker. E32 uses the same brain as the E34 and pre 09/94 E36 use the same brain as post 09/91 E34. The early brains have the mounting bracket attached, but the late ones have a separate mounting bracket which you will need to remove from a wrecked car.

Clutch switch (for manuals) - you will need to add a clutch switch. They are all the same. On E34s you will also need to add the small clutch switch mounting bracket.

Clutch switch (for autos) - this is a tricky one. The autos that I've done have the wire in the loom for a clutch switch, but this needs to be jumpered so that the cruise will work (since there is no clutch). I have always used a factory made jumper from a wrecked car. They did change the connector for this at some point. 89 and 90 E34s that I've done have a two wire clutch switch connector and the 94 E34 had a 4 wire clutch switch connector.

Safety cable clips - don't forget to add the safety clips to the throttle cable at the throttle body. Don Gale has some info on them on his web site. -

[genphreak]

Awesome info Myles- thanks. I have been battling with e30 whish use E28 and and later type setups, they change heaps of bits but your suggestion that one simply needs to change the thrttle cables around I was not aware of- I might experiment some more- the old e30 style setup appeared not to fit the late e30 (M20) we have at first- but I now suspect that it will with some tinkering (have to get the right bracket though)

Great work- I need to remember what you've contributed as I have an M50 525 to convert now. Just need the parts, however I have an e28 actuator so might try this depending on what I can get

Cheers, Nick

[Lordsneldon]

myles, I am trying to fit a cruise control to my 94 e34 auto, i have the corect actuator, taken from a wrecked m50 and also the column stalk, but I can't see the plug in the engine bay for the actuator, but i managed to find the one for the stalk????

[Jon K]

If anyone needs a cruise control actuator I have one from my 1992 525i. I suppose there is also some computer/module, I would have that too

[myles]

myles, I am trying to fit a cruise control to my 94 e34 auto, i have the corect actuator, taken from a wrecked m50 and also the column stalk, but I can't see the plug in the engine bay for the actuator, but i managed to find the one for the stalk????

I found mine between the aux fuse/relay box and the left headlights tucked up under the left front guard next to a bunch of earth wires.

[genphreak]

If anyone needs a cruise control actuator I have one from my 1992 525i. I suppose there is also some computer/module, I would have that too

Let me know Jon, inc. USPS shipping to Aus! I'd take your ICV too, but mine has proven ok now. My intake backfire on warm start was due to the throttle body heating (me thinks) now dosconnected all is good except starts are not immediate, like with the M30s.

A decent suggestion is that they heated the TB on the M50 to maintain emissions during start/warmup, not just to prevent icing of the butterfly. No doubt you disconnect yours...

[Jon K]

Genphreak-

Yeah I have no coolant lines to the throttle body. I don't have much, if anything, in the way of emissions any more though. I am not sure how the coolant would change emissions, but who knows!

I am willing to ship it anywhere for a decent price! Make me an offer in PM if you want anything. Anything else you might need just inquire, as I have a ton of stuff that I don't think of immediately.