DME relay test
12-27-2003, 01:11 AM
#2
It's not worth it to test it. Most of the time they're intermittent and may
test good but fail later. Just buy a new one and one one as a spare
in the glove box.
For info only the following:
Function; the ignition (86 & 85) closes contacts for power to DME (87),
and DME (85b) closes contacts for the fuel pump (87b)
86 & 85 & 85b should be the coil windings
30 & 87 87b are the contacts
Have Fun
Loren
'88 3.2
test good but fail later. Just buy a new one and one one as a spare
in the glove box.
For info only the following:
Function; the ignition (86 & 85) closes contacts for power to DME (87),
and DME (85b) closes contacts for the fuel pump (87b)
86 & 85 & 85b should be the coil windings
30 & 87 87b are the contacts
Have Fun
Loren
'88 3.2
12-27-2003, 02:44 AM
#3
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Why are you wanting to test it? Is there a problem with starting, or fuel pump not working? There are actually 2 relays built into one relay. The way it plugs in, the contactor towards the front controls the f.p. the contactor closest to the plug sends power to the DME control unit, that portion on the relay gets its signal from the Ref. mark, speed sensors. To see if they are both closing, disconnect your batt. unplug relay, take cover off relay, plug back in, actuate key, watch to see if both contactors close when you turn the switch to start it. If both contacts close, and engine starts, the relay must be good. Good idea to keep spare in glove box though, they are cheap enough, about 35 bucks.
12-28-2003, 02:20 PM
#5
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Only one contact closed when the key is turned so it needed to be replaced. A new DME was all it took! I did test fuel pump and injectors by jump wiring 86 to 87and87b,everything fired up so the DME relay was the problem. A little hint when shopping for a part at a Porsche dealership, Call other close dealerships (say within 300 miles) and ask what they charge for the part. Your dealership should match it. The DME relay was $55 in Naples FL. but $45 at Champion in W.P.B. FL. so I got it for $45 in Naples FL.(SHELTON PORSCHE) Ten bucks isn't a lot but imagine if is was the DME control box I might save hundreds! Pays to shop by phone.
