Electrical oddity. 98 Jetta Mk3 TDI

ozymandias

Active member
Joined
Mar 19, 2010
Location
Desert, NM, US
TDI
1998 Jetta Mk. III
First off, sorry if this is a common problem to have, but not common enough to where it pops up on simple search. Anyways..

So I start up the engine and release the E-brake and the 'brake' light doesn't go off, but just dims a bit. The brake doesn't seem at all engaged and i can drive normally, but also there seems to be no power in the center console. Just the environmental controls. No fan. No AC. No recirc.

This happens fairly often, EXCEPT if i turn the fan on before before releasing the e-brake. If i do that, everything is fine. This seems like a weird controller problem... kinda...

any ideas? weird, right?
 

ToothFaiery

Member
Joined
Nov 25, 2015
Location
Georgia
TDI
98 Jetta TDI, 2005.5 Jetta TDI
Electrical Problem

Did anyone answer this question. I have a very similar problem, no blower, plus wipers don't work. I have to let the car run a minute, turn the car off, remove the key and then start again. Sometimes, I have to repeat a few times before all will work again.
 

Lug_Nut

TDIClub Enthusiast, Pre-Forum Veteran Member
Joined
Jun 20, 1998
Location
Sterling, Massachusetts. USA
TDI
idi: 1988 Bolens DGT1700H, the other oil burner: 1967 Saab Sonett II two stroke
T-F,
THere is a relay used to turn off a bunch of items during starter motor operation. This make more of the electrical current available from the battery do just to the starter.
The items you mention, and headlights, rear defroster, and a few others, are powered by this load reduction relay (LRR).
It may be that the contact (switch) within the relay isn't making a good connection after releasing the key from the start position and this prevents electric power from reaching those items, or the electromagnet coil in the relay isn't getting its power from the ignition switch when the key is released from the start position.

Knowing that the B4 Passat of the same era had a lot of ignition key switch issues (not column lock, just the electrical part of the lock and switch assembly), I'd try there first.

Start the car. If the electrical items do not come on, jiggle the key a bit or press it straight in deeper, no turning, to see if the items come on again. That's a sign that the contacts in the switch part of the lock/switch are receeded into the plastic that holds them, as happens with the almost identical B4 switch. It's not easy to get access to replace the switch, but it is a known, permanent remedy.

If the jiggle the key method doesn't work then it may be the LRR. It's a lot easier to access, not expensive to replace, but the new one won't work either if the problem is the key switch. That's why I suggest at least identifying if the key switch is a culprit before buying a LRR.
 
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